Awesome video. You always hear these different new products that clean to do awesome things but it's great to see somebody actually put them to the test
Good video and good information. In 1980 I made a mister system with oil burner nozzles, a 24V solenoid valve, and a time clock to keep 8 low temp refrigeration systems on a supermarket running during the day when the oa temp was above 85 degrees, from June through August in Tennessee. These were older Hussman systems with undersized condensers. It increased the capacity and kept them running. It will work if it's the only alternative. It will also work temporarily while you are finding a replacement condenser fan motor. And it will help, in addition to throttling the suction service valve, if you have to do a hot case or walk-in start up low temp system on a really hot day. I am talking about roof top refrigeration condensing units when roof top temp is about 15+ degrees above ground level temperature. In these last two examples you don't need a mister, you can just use a water hose and fine spray nozzle.
The misters work in humid Houston but any energy savings is offset by the damage to the coil when it is clogged with calcium deposits and will accelerate the rusting of the steel surfaces on your condensing unit. You can buy a device that treats the water and supposedly prevents the deposits on the coil but I found that device to be expensive to maintain. You can build your own misting system using misters available at Home Depot, a sprinkler valve, and a small transformer to switch on the sprinkler valve when the condenser is running. As others have noted, it might be beneficial to only run the misters on 100+ degree days so a thermostat could be added for that function. How do I know all of this? I built a misting system as an experiment over 20 years ago.
He forgets that if the mist isn’t evaporating in high humidity that it won’t work. When that moisture wets the hot coil it’s going to evaporate regardless. The evaporation will still drop the temperature and remove heat. It’s not dependent on the air alone. So unless you can show me results based on Humidity, I’m betting your wrong.
Thanks for the good info! The kit I recently looked at buying included a filter and had a much longer hose than yours with I think 12 spray nozzles! Not sure how much difference it would make, but the instructions on it said to have the jets angled to that they sprayed mist directly on the condenser coils!
I did this, but instead of using misters, I used running water and caught it in a catch-pan and recycled the water. Month over month, I dropped at least $20 off my power bill. And this was during July/August, hottest months in Florida (not to mention the humidity) One thing you didn't mention was how long the unit ran to keep the house at the right temp. If no mister, and the compressor runs for 80% during the day, and with mister runs 60% during the day, I think that also makes a huge difference on wattage consumption. 100W difference between mister vs non-mister is one thing, but reduction in run time over the course of a day is another.
This one is interesting. Your method is probably the worst way to use water on a coil. As the water evaporates, the minerals stay in the water and become more concentrated. Eventually, very concentrated minerals will be deposited on the coil. Determining energy savings by comparing the electric bill is very inaccurate and should not be trusted. I will be publishing a video on indoor air performance in the near future. GFM
These type filters are not designed to remove all minerals from water. They are "treatment systems". When water evaporates, whatever is in it is left. That means deposits on the coil. Even if you put an RO filter in, you are then faced with pure water. That may sound good, but pure water is quite corrosive so then you would have a damaged coil. GFM
When I worked in the telecom business, I've misted the data center or computer room condensers when we'd lose a fan motor, and could keep running until the repair tech could come out to change out the motor.
Thanks! Very informative. I was seriously thinking of buying that $200 misting kit but I'm glad I watched your video. I'll just make sure the area around the condenser of clean and no grass, weeds, or grass clippings get in there. Maybe occasionally spray some water into the condenser on a very hot day especially here in Houston, TX.
I once had an process cooling and dehumidification installation that incorporated a l5 ton Trane condensing unit. One of the accessories that was spec’d for the condensing unit were evaporative pre coolers for the condenser coils. These were swamp cooler like modules attached to the condenser coil inlets, and used to make the condenser more efficient by pre cooling the condenser entering air temperature. It actually worked, until the calcium and hard water deposits that were left behind ruined the condenser coil. You basically turn an air cooled condenser into an evaporative condenser, which is more efficient, and will run with a lower condensing temperature, thus a lower amp draw to run the compressor. It’s fine as long as everything is clean, but once scale starts to form, the efficiency goes away.
I live in Altus, OK and I have a coworker who used a sprayer for 10 years and his system is still running. The water is very hard and he has a filter on it. So the 'expert' has little knowledge on this procedure. I had a system built in 1984 and used this and cut my bill down by 100 dollars per month. The system worked for 8 years until the motor and blower went out.
I’ve seen several videos made by homeowners who don’t know how the hell an a/c works demonstrating their mister systems and claiming it saves them all kinds of money. It’s good to see someone that actually knows what he’s talking about make a video that shows actual numbers.
JD. It doesn't matter if you understand the principles of AC or not if you notice that the utility bill goes down after you try it. On the other hand the home owner might not realize the condenser fins are becoming crusted with calcium until a few years later when it becomes very inefficient.
Most new window units splash the condensed water onto the coils, this increases the energy efficiency ratio (EER) but at the expense of the coil oxidation. I typically drill/tap a drainage on these units so that they may last without premature weathering.
@@DarkLinkAD why are you bothering changing the way it's designed to function, condensed water does not have the calcium and mineral deposits in it that tap water does.
@@44hawk28 It absolutely does. Any pool of water will collect minerals and accelerate corrosion. And my A/C funtions perfectly well, at 42F on a 98F day.
@@DarkLinkAD yes water will collect minerals. But can freshly condensed water, just like distilled water as far less concentrations within it. Perhaps you don't understand but water that sitting on the ground where there's a hell of a lot of minerals and water that condenses on a fairly clean object are in two totally different environments or perhaps you believe the calcium sound of thin air when water condenses.
I had an older unit that I was trying to limp through an incredibly hot summer. The unit was having a hard time keeping the house cool it was so hot and the unit was so old. The water misters did help the unit maintain temperature inside the house which it wouldn’t do without the misters. Now the outside temperature was hitting around 105 and did so for about 2 weeks. So in that extreme of conditions it might work a little better, but fortunately, we don’t see those conditions that often.
At 2 minutes 40 seconds you said what I was waiting for. Number 1 son is selling everpure water filtration along with other HVAC services. After some time with this company, he has noticed the filtration systems are not performing as promised. I would think, if misters were beneficial to the condenser, manufacturer's would have installed them years ago. Great subject and video with lots to think about.
Consider if, as a manufacturer, I could increase the efficiency of my air conditioner by 20% just by adding this product and not have to spend many thousands (or millions) on higher efficiency compressors, fan motors and coils. I would do it in a minute. Obviously, it does not work well. GFM
Great video. Thank you for being objective about everything. I see now that this would not be worth the detriment to the system. I'm in Florida near the water and everything likes to rust so added water would really exacerbate the problem.
I wonder if you would achieve similar results by directly cooling a six inch section of the AC pipe directly with slowly running water. The used heated water could also have great benefits for use in a nearby small underground irrigation system. Another variation of this theme is to cool a small section of the AC coil with the water using the water supply line that feeds the house. There is lots of water usage in a typical house during the day from flushing the toilets, using the sinks, washing machine, taking showers, etc.
I just spent 4 hours removing the hard calcium crust on the coil fins of my 4 ton a/c condenser unit that had a mister installed two summers ago. I used a 2 inch paint brush to paint on Muriatic acid full strength to soften the crust and then went through 3 plastic fin combs scrapping off the built up. I followed that up with a strong foaming coil cleaner and lots of water. Here in Oklahoma City our water has a lot of dissolved solids and by the way I used a calcium in line filter for the mister and changed it yearly. My advice is don't install a mister on your A/C condenser unit, you're asking for trouble.
Well, it's a good idea to clean the AC system once in a while, and 4 hours does seem like a sunday project but not too bad... Vinegar is what is used in bathroom cleaning products to dissolve calcium deposits, if you get one of those soap hose mixers for car wash and put vinegar there every few weeks, you can let your misters to do the work for you.
The bottom line is the misted water evaporates, cooling the lines in the compressor. Same as evaporative coolers from 60 years ago. Since humidity is not a concern outside, this might be worth something but, you might save a few bucks per month but you get the chance to build up mineral deposits in exchange. I can appreciate the decision to blow this idea.
Thank you for making this video. You broke it down for people to see what is really going on with these mister kits. This may be worth using in parts of the country where the air is dry but anywhere else it appears to be a waste of water and money for a kit.
The only flaw I see in the test and math is coverage of the misted air, discharge temp change and run time. If you reduce your run time by an hour per day that is also a savings of not using any electric for that time at all. That is not only the condenser, but also the evaporator fan at 200 watts or more for that savings period. If that savings is enough to offset the water increase then it's a plus. Add in the treatments to clean the coils monthly and your time... Maybe a wash, but personal time vs TV watching is less electric usage. #1 if you bought a spec house, everything in it is cheap and inefficient. Get in that attic and add some insulation. Add attic venting, add solar fans, add soffit venting, add a wrap or two to the A/C ducts, cover the evaporator with a wrap but make sure you only strap the insulation in the service side. Next service your A coil yearly. Imagine one filter worth of dust getting into the A coil. If you haven't cleaned it in 5 years it'll look like a shag carpet. If the envelope of the house is crap, the AC will perform like crap since it'll almost always be clogged... BTW most filters don't last more than a month, I don't care what they write on them. Can a mister system work on an already inefficient AC? I believe so, but you better help it all you can. 50°F discharge air flowing through R4 duct may pick up quite a few degrees in that 140°F attic then come out as 65°F air at the register. This video shows a far superior AC than most viewing have. I do still stand on the run time statement. Very good math, just overlooked an element.
I would think it would add cooling capacity on hot days when humidity is not excessive. Additional capacity might be more valuable than energy savings when your system is slightly undersized in extreme temps. What is your opinion on that gfm?
Jim Damiani I plan to use this system exactly for this. The outdoor temp can shoot upto 45-50°C while is AC unit is only rated to run upto 43°C, so this system can possibly help me on those super hot days.
The unit in this video also looks pretty new and nice. It's probably operating pretty efficiently already. But if it was an old POS that wasn't efficient, a system like this may have more of an effect. Just a thought.
Valid point. However, in that case, cleaning the coil would be a much more effective way to improve the system's efficiency than modding it anyway, and therefore should come first.
This analysis is completely ignoring the amount of time the AC unit is running. Misting the outside using makes the exchanger inside the house colder. This cools the house faster, which allow the AC unit to run less time overall. So, an AC unit that is not running is infinitely more efficient than an AC unit that is running. Here's how I know this to be true. Yesterday, the temp was in the upper 90's where I live, and the AC was not keeping up. So, I went outside, and "misted" the coils with a hose. I came back inside, and within a few minutes, the temp in my house dropped 2 degrees. A few hours later, the temp was high in the house, misted it outside again, and the temp dropped again 2 degrees in the house. This tells me that misting the outside unit kind-of "supercharges" the AC. On a regular day, it would allow it to run less often. You didn't take that run-time into consideration at all..
The outlet temperature didn't change at all in his test so it doesn't matter how long it runs because it will take the same amount of time to do the job and if your method worked people would be using it all over the world. Systems that work right don't drop the temperature 2 degrees in "a few minutes". I don't know what your measuring but I trust this old guys expertise over your one test with no documentation lmao if you have a for example a 3 ton or 36k BTU air conditioner you can not get more than 36k btu out of it by getting the coil wet. It doesn't work that way sorry.
@@mr.monitor. what are you calling the outlet? Just trying to get my head around your response. Also, another thing not taken into account is outside temperature. No test is performed here to determine if it might be more effective closer to the 100 F outdoor temperature mark. Just thoughts. Interested to see your response. Thanks!
@@UncleMartin by outlet I'm saying the wet bulb temperature of the air coming out of your ductwork basically. Measure it before and after misting the outdoor unit;it won't change much if at all. If you turn the ac on and check temps keep in mind it takes at least 20-30 minutes to get the base temp. When a coil is wet the head pressure will drop a lot and yes will decrease the amp draw...but it will also have a hard time sub cooling(I know I know this seems backwards but its not) the now lower condensing pressure/ temperature of the refrigerant which leads to a cascade of events in the metering and flow of refrigerant that pretty much balances out anything being gained....its not saving you much if anything.
Many thanks for your test. Like you I find savings that slight not worth the risk of mineral buildup. Also, that water might be better used-and harmless-sprayed to cool down brick walls and hot asphalt. Cooling around your house should make cooling in your house cheaper.
Interesting. Thanks for making this video. I wouldn't bother with a water sprayer either. However, this water spray system may possibly be a little more effective than it looks. I say that because this water spray system may reduce the supply air temperature, which would mean that the AC wouldn't have to run as long to cool the structure, so there may be a little more savings there. Also, if it was hotter outside, there may also be more of a difference.
The theory of this thing is the atomization will evaporate the water. I kind of got a shower when working with this thing, so the humidity must be much lower for it to work well. GFM
Good point. I'm just saying that this system may lower the supply air temp a little, making the efficiency improvement a little bigger than it looks. Still wouldn't be worth it though.
Avery Alexander Having your system run less sounds like a great benefit but it's not. The less the ac runs the less humidity it will remove from inside the house effectively oversizing the unit. Couple that with any upgrades done previously like new attic insulation, new energy efficient windows etc and very likely cause humidity issues.....
I highly doubt that a water spray system will reduce the run time of the AC enough to cause a humidity issue, especially since a colder coil will condense more water as the system runs. But good point.
seems to me the only logical place for a mister setup is the hot and dry desert areas, Arizona is a good example. next problem, how much water do they have to spare?
Couple of questions: 1. Would it be possible that the misters also caused an energy savings through reducing the overall cycletime that the condensor is on and running? 2. Even in high humidity areas, where the mist wouldn't evaporate, could the fact that some of it would still be pulled against the coils as water droplets still have an impact on the coils cooling?
jeremy baumgart 1.) It's unlikely to save you money, the difference you will paying for water 2.) Google evaporative cooling and no with high humidity means less water will evaporate thus less water carrying away heat.
JB, the cycling is controlled by the thermostat inside the house. Misting either makes the unit more efficient at cooling the house or it doesn't. The cooler water should have a positive effect on condenser temperatures no matter what. The heat of the condenser will cause the water to evaporate.
jeremy baumgart I think you are right. Part of the advantage was missed(mist, nerdy pun). If the outside temp is lower it also means the inside is as well, so the inside thermostat should trip it off sooner due to higher heat transfer bringing the temp down faster. Also it appears the misters could be more effective producing an improved gain. In the end I believe this will ruin your condenser due to corrosion and hard water buildup, so I wouldn't do it long term. A dedicated heat exchanger designed for it could be made though (cooling tower). The cost is why you won't see that done commercially for residential sized units.
Freddy McIntire, I don't understand what you are trying to say. I've heard of superheat and sublimation, but never subcooling. What is it? How do you measure it?
Another very nice video. The big benefit would be a reduction in head pressure during an exceptionally hot day that could make the unit lock out on a high head pressure. Also the electric company would appreciate the lower kwh use on that very hot day. However it would take many, many people doing it to make a difference. When I ran a very large chiller, the electric company would call me to see if I could reduce the load. I did but the people in the lab building were not happy when the temps went from about 72F to 80 plus. Also need to add water cost into the cost factor. Thanks for the video's.
The dew point at the time of use will have an effect on the efficiency. Anything above a 65° dew point, pretty much eliminates any gains. However a water curtain running down the coils does have a major effect by using the temperature of the incoming water and not the evaporative effect of a mister. I run a column of water down the condenser on my four ton unit, adjusting the flow to allow a ten degree rise of the incoming to outgoing water. Right now it is 96° outside and 78% humidity. Water on vs water off is 34% reduction in input energy. The outgoing water is drained to my large pond. No mineral build up at all. Last winter we used it on cold snaps to add heat as well.
Setting aside all the potential issues related to spraying the condenser coils (legionella, coil corrosion, mineral buildup) - I'm not so sure that this one's that easy to poo-poo away. Saving energy is always a huge plus, but even putting that aside, a system like this will give the overall system a performance boost on super hot days. In the middle of summer here in Georgia, there have been times when my AC unit was having trouble maintaining the temperature - the unit would essentially run continuously just to maintain setpoint. Especially after a power outage or if it had otherwise not been running for an extended period - it would take FOREVER to get the house cooled back down on a 98 degree day. Manually (temporarily) spraying water on the condenser coil to help it shed heat has always helped the situation. It's incorrect to assume that on a very humid day a system like this would lose ALL effectiveness. Sure, on a low humidity day, the air itself is cooled before passing over the coils, but a MUCH larger transfer of heat takes place when liquid water evaporates directly off of the coil surface. So even if the humidity was at 90%, liquid water being forced to evaporate off of the much higher than ambient temperature coil surface ensures that there is still a cooling effect. Think about it, even on a crazy hot, super humid day in Florida, and even right next to the ocean, everything still quickly dries (the road, patios, decks, etc.) right after it rains. Of course, the TRUE issue with something like this is what I "set aside" in my first sentence. Spraying water onto the outdoor coil clearly has a benefit - it's just that doing so is very likely to cause damage the system. Figuring out a way to get around all the mechanical risks is the key to making this work...
Growing up in West Texas, we used swamp coolers, I’m wondering if a shroud, using that technique, would cool the surrounding air without the mist harming the coils.
I know that I have ran water over the coils and as I started the air was hot. But once the coils got cooled down from the water I was spraying it was considerably cooler coming out of the top of the compressor. Those were my thoughts exactly. Just like in a fractionation plant the cooling towers have a huge water reservoir and water is used the same way to cool the process.
Thank you. I was sure considering this, since I live in Houston and my electric bill was ENORMOUS in June. But, I am glad that you did a realistic test. So, I will not do this now.
I enjoy your videos and knowledge I gain. Not long ago on Ask this old House show they showed how an air conditioner condenser was used to heat up a pool via freon circulation somehow. Very interesting and my thoughts were why not do this for hot water tanks inside the home
There are several ways to do this. One is use a "superheat remover" on your AC. It is a heat exchanger that is connected to your cold inlet of the water heater. Another is a designed "water heater heat pump" best used in southern climates. One more is an air heat pump that can be used to warm water or cool the structure. GFM
Well, your test showed a definite improvement in the operating efficiency of the AC unit and you didn't optimize the misting heads or spray patterns. This could be done with rain water and a pump that is driven by a solar panel w/battery, as the pump would not require much power. The point about humidity is valid in the context of ambient temps, however you also need to consider that the A/C coil is hotter than ambient temperature and therefore will heat the water enough to cause it to evaporate. Think about it - no matter how humid the weather you can still boil water and produce steam...well, the AC coils won't boil water but it will certainly still evaporate and improve the transfer of heat from the coil into the air. Also, the water can drip off the coils and provide cooling in that fasion. If I was going to do this, I'd probably catch rainwater out of a gutter pipe. The concerns over damage to the coils are irrelevant with proper and simple maintenance, like cleaning the coils as needed.
I don't think he knows what he thinks he knows, or that there are things that he doesn't know, or that there are people who know things that he doesn't know.
Yep, and he can also up the AC efficacy by cleaning the coils/innter system out once a year. Plus you could give the AC unit extra shade by placing a large beach umbrial over it. Or plant two trees near it.
Rain water isn’t a great solution for this as it’s likely not going to be as nearly as cool (relatively to the ambient) as tap or well water would be. That being said… this guy making the video isn’t taking into account if the system is running less to achieve the same temps inside the house. In other words, if the temps across the evaporator inside the house are dropping, the air coming out of your vents is going to be cooler and the system won’t run as long. Not sure if there is any truth to that but it’s a factor he never addressed
The only real-life application where a mister system make sense is a large commercial unit that has doomed condenser coils. It can buy you a little bit of time while you get the budget to replace the coils or the entire unit. Excellent video, sir.
Do you think it would make sense for old commercial condensers in a humid state like Florida? This is the only company I've seen on the internet that promotes misting systems: smartmistsystems.com/ac-mister.html
Peter Valadez Florida is typically very humid so the evaporative effect is lesser than a dry area. Again, for a large commercial application where you are planning to replace the equipment; it might buy you some time. Typically, a commercial mister system would be a 1/2" copper pipe run along the outside of the unit with Ts and mister heads every few feet. The system is controlled by a solenoid valve that opens when the head pressure gets too high.
I did design my own setup using a small current sniffer to turn on the water to the nozzles that detects the AC unit turning on without physically being connected to it and it draws just a few watts when running but I am also using a timer so this thing only kicks in when the sun is hitting the heat pump directly which is for about 3 to maybe 4 hot hours a day then it tapers off as the sun starts to set. I f I had to give an opinion I would say that the air in the house feels a bit cooler but that could just be psychological. Just a side note: Your video was done very well covering this topic and is one of the better videos on youtube. Thanks for making this video.
That's why you have to run a filter to make sure you're pulling garbage out of the water. We don't have calcium issues here so that's not a concern and as far as running this thing and damaging the AC unit outside that's not going to happen anymore then rain coming down from the sky while the thing is running and causing damage to it. I do understand where you're coming from but this thing only runs during the peak heat of the day which is only for a couple of hours when the sun is directly shining down on the unit outside. In other words I've got it setup on a timer and I don't even bother running it unless it's close to Triple digits outside.
The sun hitting the condenser coil directly will reduce the cooling system effectiveness. Your strategy might actually help with improving the cooling efficiency.
Anything that lowers high side pressure is good & the system doesn't have to work so hard ... If you don't believe me start your car turn on the AC & let someone spray cool water from the hose on to the condenser & see the difference it makes on the inside air temp coming out the vents in the car
Wrong, there is normal operating head pressure and excessive head pressure caused by several different factors. In a situation such as a fan not moving proper air across the condenser coil, (dirty coil, replacement motor of wrong specs, motor running in wrong direction-yeah i have found that, etc.) introducing water that is evaporating will effect the systems performance, but this is a band aid effect. the correct course of action is to insure that the system at both sides is operating within correct perimeters. condenser coil is undamaged, clean, and proper airflow over it. evaporator coil is clean, proper airflow across it. This will also include, compressor operating properly refrigerant charge within range, based of of proper airflow, sub cooling and super heat within manufacturers specs for current conditions. If spraying water onto an air cooled condenser coil had merit, all the manufactures would have standardized it long ago.
I see it mainly as a way to get a struggling unit through a bitterly hot day. If someone really wants to try it, they might as well save the $60 and use their lawn sprinkler or even a hose nozzle positioned on a post nearby. What are the capacitor and Victor trap for? Just to see who's paying attention? :-)
I agree Bill. It'll also probably help if the unit is undersized. And by the way, I love your channel. IMO, you have one of the best channels on RUclips. Keep up the great work!
Been there, done that. On a large commercial condenser that kept tripping out on high pressure in D.C., during a heat wave. It's a real "duct tape" type solution, but it got us through until my boss got money approved to replace the unit.
Perfect use for it. My system is leaky and 20 years old. I will be replacing it in the spring, but need to get it through this summer. I am basically doing the same thing with an old misting hose and turn it on each day. It is amazing the difference in how it is working, you can physically feel the air is cooler coming out of the registers & the unit runs much less often. I will not do it with the new one, but with every day being 90 degrees in NC & the hot sun heating up my attic, this has limped me through the summer nicely.
As an AC tech who has done this and also worked on evaporative cooling towers, I don't even want to get into the subject of water hardness and calcium deposits. What I do want to say, is when you lower the head pressure you will correspondently lower your suction pressure, and this will give you a correspondingly lower evaporator temperature, which can give you a little cooler discharge air. Not much, but some. Sometimes large systems would get away from us on hot days, and with hot rooms and hot outside temperatures, we would try to start a system up, but it would trip on high pressure. We would then run the system while spaying down the condenser coils until the rooms cooled. Then the suction and head pressure dropped, the load decreased and then it would run ok without water being sprayed on the condenser.
This is a very good forensic analysis if misters are actually beneficial in reducing head pressure thus reducing amp draw on the compressor. I am not very keen on blowing city water on to the condenser coils because of calcium build up. I just put a stand alone high velocity fan blowing into the condensing units coils. I really dont know if it really helps because I dont have an amprobe any more or the correct gauges to see if that stand alone fan is doing any good. Where I live electricity is real cheap so I am not worried about that. All I am interested in is reducing the compressors head pressure to prolong its life. I am a retired electrician but over the years I have learned a little on how central air conditioning works.
I've seen the rabid know it all videos who never worked on a/c systems put down veteran a/c contractors who do not agree on this snake oil version of savings, when I rinse a coil on a hot day the indoor area feels clammy while the coil is wet, what about premature rusting and I'm sure every one of these guys have a water treatment setup to prevent any minuscule scaling on coil, does the mister price win over the paltry savings and extra little water usage, some of these also want to build an enclosure to keep the sun off of condenser no such thing as high head pressure on a covered condenser, JK, some companies void warranties if they come upon a condenser with a bad compressor that has an enclosure, but what the hell do I know about a/c systems in my 20 yrs of doing it.
Outside in normal elements not the same as continuous. ever see a condenser get continually marked for territory, as in pissed on daily by the family dog? wrecks it, granted piss is harsher than city water, but natural elements are much softer than this misting system idea.
Nice test! A lot of window AC units have actually done this for a long time. The condenser fan at the back of the unit has a plastic ring around the blades that picks up condensate water and throws it at the condenser coil to help it cool. All 3 of my window AC units do this, even the 30 year old one I found in the trash. Someone actually drilled holes in the bottom of it, which rendered the water mist cooling ineffective. However, the unit did seem to perform better when I patched the holes. Obviously window AC units are pretty limited on how big the condenser coil can be, so that might have something to do with why it's so effective. Anyways, I thought you'd find that interesting
Condensate is pretty much mineral free (As long as the evap coil isn't coated in buildup) so it's no harm no foul to get the advantage of evaporative cooling to help the condenser coil. Split systems though the condensate has to travel quite a distance and may not even exit the house on the same exterior wall the condenser coil and compressor is on, hence why it's not used on residential units. Plus with the way most split systems suck air through the coils no cheap and easy way to sling on the condenser coil and even if you did then dust and dirt would potentially build up and turn to mud (a problem that even window units can have if not maintained). Large commercial plants do use water spray but they treat the water and those units are often different in layout.
@@Cragified Good point. The water mist system definitely makes window AC coils get dirty faster, but I haven't seen it cause corrosion or buildup since it's basically distilled water. But I think for most people it does more harm than good over the long run since hardly anyone bothers to properly clean their window AC units.
These misting systems are very dependent on humidity. Just like the patio ones that make sense in a dry area like arizona where the humidity is low but not here in Alabama where its high your just going to make things worse. Also the hardness of the water is a big deal as that will clog up your system in no time. So Desert environments maybe, but else where your wasting your money and in the end its going to cost you in repairs. Great video test of these, thanks!
The water is just another medium for removing heat. It will lower head pressure and it will remove heat. Evaporation is one factor. The temperature of the water is another. The temperature of the water will lower the air temp at the condenser. It will not affect the indoor humidity in any way. If it was an emergency like an old unit that can't remove heat anymore then its a great solution until you can replace it. On a new unit it will accelerate corrosion and shorten equipment life.
Michael Paddack ... and it messes up the coils and it rust out the body and makes a general mess and it is not recommended. Experience has taught me that snake oils do not work and I'm an air conditioning technician. I'm not a God I'm just saying you need to keep this simple and not mess your coils up
60F water would sprayed directly onto the coil for water to gas cooling, but as a mist with humidity at +90% or raining lol. evaporative swamp coolers are a good example, they don't do any good in humid areas. non evaporative types using cold water through a radiator or heat pump with liquid to gas condenser will work good. but then you have many more failure points and need pumps, filters, glycol antifreeze, etc.
I agree with the whole calcium thing as well. That was the first thing I thought when I saw these things. Hey can you make a video on the difference in energy,efficiency, and/or comfort if you leave the fan on instead of auto. Iv always felt that when the fan is on, the temp. is at its best comfort. But how much in energy is the difference and does it matter on which metering device. If you can. But regardless thank you. Glad your still makeing videos.
you did miss one important factor!!! the temperature of the air blown inside I believe if the air would be colder that would mean the unit runs less time.
Less run time equals inefficiency. They don't become efficient short cycling. The longer it runs the more efficient (20 minute cycle much better than 5 minute)
certainly an interesting concept. The industrial units are MORE cost effective due to the scale of the system. Always hidden costs of time, materials, water, cleaning minerals on coils, water filter (which won't get it all).
We had a site not willing to replace u units just yet. But on hot summer days coil efficiency was lower Than it should be. Units would trip on high head pressure. We installed misters there to keep it tripping out.
While you can achieve sub ambient temperatures through evaporation, you lose efficiency over time through scaling of the coils. In addition the cost of the water and if used descaling system and maintenance. The commercial systems use a waterfall with recycling their water, water treatment and coils designed specifically for water sub ambient Cooling.
Thanks for the showing the actual number so we can see if it is worth the hassle. We have nearly 0% humidity so I think it would be more effective here. But, if you even triple the cost savings at 21% I might get $10/mo. Now that is closer to being worth and it since my air runs 8-9hrs a day I might even get a bit more. HMMM!
I have a shade structure to keep direct sunlight off of my ac unit mainly for earlier parts of the day when the sun is directly over plus misters. of course i have an older system thats quite old but still cools pretty decent.
I live in the hills in LA and while it uses water, the unit cools my home faster and maintain a lower overall temperature. My house is older and the upstairs has no insulation just beams. I guess I am lucky because those mini swamp coolers work too
If misters where something that worked and delivered a 20% savings, AC manufacturers would add it. Manufactures would have there "marketing"demons touting it.
Evaporative cooling could certainly help in an arid climate to boost the efficiency of a closed system like this. The reason that AC manufacturers don't do this or implement it is because they have little financial incentive to. They don't pay for the AC bills that customers incur. If they added a system like this, their units would be more difficult (and expensive) to install, and they'd have to warranty more parts, which they also don't want to do. The real problem is total cost of ownership. Customers aren't savvy enough to know how to forecast their usage effectively, and thus wouldn't be able to understand if something like this would make sense financially. I see builders foolishly installing these condenser units on the sunniest spots of the properties out of convenience for them, apparently not caring that it will then get extremely hot during the afternoon when the demand for cooling is at its peak while the heat rejection part of the system is also in direct sunlight, and therefore is at its least efficient. Same thing for both parties: lack of craftsmanship and care for their customers or for the environment.
Michael Horsford Do they just mist water out in front of the condenser coil, or are they using pads like a swamp cooler has? The only systems I've seen that both work, and don't damage the equipment have some sort of water panel, basically a swamp cooler pad, in the air stream before the condenser.
Industrial ACs do this. One problem with such permanently hot and damp systems is that dangerous bacteria and fungi thrive in those conditions so the units have to be periodically inspected and treated (chlorination, peroxide or other) to prevent potentially severe and lethal outbreaks.
I was in The Bellevue-Stratford Hotel in Philadelphia at a ham radio convention at the same time as the Legionnaires' had there convention. The outbreak of Legionnaires' disease killed something like 30 men, quite a few people got very sick. I had my wife and 3 month old son with me, the CDC and Philly police came to my house and talked to us, we never got sick.
Another thing to consider, some ice machines run off a water cooled condenser for 10 to 15 years with no significant scale build up. Scotsman, Manitowoc and Hoshisaki all make water cooled units. Same with some hydronic systems. Will think about this for a while!
you know there's "heat pump/geothermal" condensers using water from lake/pond or loops in ground/wells right? the down side is they have many more things to go wrong, like pumps, filters, controllers, balance valves the risk of freezing in cooler climates and heat pump mode. so you have to run and maintain glycol in them. i'll avoid commercial size "chillers" and towers :)
I have done the exact same testing myself, with much different results. The only difference is that you used an insufficient amount of water to be effective. My test was conducted on a unit in full shade on a 100 degree day in west KY. (humid) Like you, my unit was running at 10 amps. With a generous amount of water the amps dropped to 6.5 or so, a huge improvement. I could hear the unit unload as the pressure decreased. Environmental conditions can and will make a major impact on results, therefore the savings will vary from day to day. But the theory is absolutely solid. Performance may vary with your experience. LOL
Thanks for the video. Just wondering isn't the job of compressor is to raise the temperature higher than outdoor ambient temperature to release heat? And therefore it'll change the subcool/superheat?
It is the job of the compressor to raise the condensing temp above the ambient. Subcool and superheat are not directly related to the condensing temp. GFM
I've always wanted to try having a swamp cooler pointed at the condenser to see how things would go. I know in the Arizona desert this would keep the condenser and compressor much cooler which would keep the AC unit running more effective along with the compressor lasting longer.
I used a garden hose with a spray nozzle ti test mine. I only saw about a 6% reduction in running watts in the morning with an ambient temperature of about 85 degrees F and fairly high humidity. Testing it in the late afternoon after the ambient temperature was over 100, I saw about a 30% reduction in watts. We’ve been running with a very low humidity in from about mid morning to evening so not sure how much the humidity helped vs the ambient temperature. I’m seeing running watts go from about 2000 watts in the early morning to about 2500 watts in the evening.
These work great in areas with low humidity. In high humidity areas there is nearly no evaporative cooling capacity, so very little power decrease is noticed.
Ok, you made an instant test, but I'm pretty sure that the unit is going to cool the room faster because liquid refrigerant is going to be cooler getting a better efficiency. Probably the compressor is going to work less time. I'd try misting the system for a whole month or more and compare to see if power consumption has really gotten lower. Thanks for your videos.
It depends on your climate and what the humidity is outside. Places like West Texas during the summer months it really does help reduce power by about 20%
A large industrial building I work at installed roof top misters and our roof heat load was reduced by about half. This reduced our electric bill by about 20%. A waffle hut in Alabama installed a lawn sprinkler on its roof and they told me it reduced their a/c bill by 30%. Of course it is controlled by a computer. I. would like to understand how must any added roof maintenance may have been. Thanks for your real world evaluation of a/c condenser coil misting.
The use of misters on a roof can be effective in reducing roof load on A/C systems. However, when large drops in power usage are listed, I am always skeptical. Power bills are notoriously unreliable in determining drops in usage as no month is the same. It also indicates there is a problem with insulation of the roof. GFM
That same principle is used in newer window air conditioners. The bottom of the case fills up with water and the fan slings water onto the condenser. They also fill up with algae too if you don't put an ounce or so of bleach into it every now and then.
may I have an idea of the ambient temperature and relative humidity. because the humidity affects the effectiveness of the spray making it easier or harder to evaporate and the temps also affect how fast the water evaporates too. also, I would like to know if the ac was running under direct sunlight this misters thing will work better. Thanks
Interesting. Our electricity is 20 cents a kw/h and our 1988 unit draws more power than the one in this video, so might be worth it. One benefit not mentioned is the reduction in how hard the compressor and motor have to work and effect on lifespan. My 30 year old machine might like a bit of a break.
Calcium is a dissolved solid. The only way to remove calcium is reverse osmosis or ion exchange (water softener). When you use a TDS meter you will see from softened water that TDS is the same. That why it's called ion exchange. Good decision not to keep spraying that nice Trane. It would absolutely clog the coil eventually. This was an awesome video. Thanks for sharing the research.
Hey nice vid informative , thanks for this I agree let it B, but was wondering in the other side of things do you think by doing this your AC unit over time doesn't WORK as hard & we get longer life ???
If your A/C is charged and installed correctly, with normal maintenance, it will operate with 100+ degrees F ambient for a very long time. It is designed for this use. What happens when you install misters is that you introduce an abnormally low head pressure that changes the hi side/low side relationship which can reduce compressor cooling and change superheat. GFM
Is it possible that some of the efficiency of the misters is the result of the AC actually getting the refrigerant colder for the same/similar amp usage? My vents feel like they blow colder and the compressor does not have to run as frequently to keep the house at the temperature setpoint. Even if the AC only uses 6% less energy while running, the total energy savings is still a lot more if runtime is also reduced by 15% (for example).
Хобби
He sounds like Hank Hill... great video!
He sells misters and propane keeps air conditioner cool and bar b que hot
Boy I tell you what 🤣
Desirey & Taylor Channel 🤦♂️he sells mister and misting accessories
Tell ya hwat
This comment section is a hoot 😂
I run my misters out west when we’re in the 90’s to 100’s, and our humidity remains well below 20%. Huge improvement!
YES, I BELIEVE YOU HAVE TO HAVE VERY LOW HUMIDITY FOR A BETTER OUTCOME, IT DID NOT MAKE ANY DIFFERENCE IN FLORIDA AT 78 PERCENT HUMIDITY
Awesome video. You always hear these different new products that clean to do awesome things but it's great to see somebody actually put them to the test
Good video and good information. In 1980 I made a mister system with oil burner nozzles, a 24V solenoid valve, and a time clock to keep 8 low temp refrigeration systems on a supermarket running during the day when the oa temp was above 85 degrees, from June through August in Tennessee. These were older Hussman systems with undersized condensers. It increased the capacity and kept them running. It will work if it's the only alternative. It will also work temporarily while you are finding a replacement condenser fan motor. And it will help, in addition to throttling the suction service valve, if you have to do a hot case or walk-in start up low temp system on a really hot day. I am talking about roof top refrigeration condensing units when roof top temp is about 15+ degrees above ground level temperature. In these last two examples you don't need a mister, you can just use a water hose and fine spray nozzle.
The misters work in humid Houston but any energy savings is offset by the damage to the coil when it is clogged with calcium deposits and will accelerate the rusting of the steel surfaces on your condensing unit. You can buy a device that treats the water and supposedly prevents the deposits on the coil but I found that device to be expensive to maintain. You can build your own misting system using misters available at Home Depot, a sprinkler valve, and a small transformer to switch on the sprinkler valve when the condenser is running. As others have noted, it might be beneficial to only run the misters on 100+ degree days so a thermostat could be added for that function. How do I know all of this? I built a misting system as an experiment over 20 years ago.
I ordered a filter and no trouble here, also very hard water.
@@marck4211what kinda filter did you get
Have you been using yours for all 20 years? Curious about the long term damage/scale on the coils.
He forgets that if the mist isn’t evaporating in high humidity that it won’t work. When that moisture wets the hot coil it’s going to evaporate regardless. The evaporation will still drop the temperature and remove heat. It’s not dependent on the air alone. So unless you can show me results based on Humidity, I’m betting your wrong.
Thanks for the good info! The kit I recently looked at buying included a filter and had a much longer hose than yours with I think 12 spray nozzles! Not sure how much difference it would make, but the instructions on it said to have the jets angled to that they sprayed mist directly on the condenser coils!
Yup not away it makes a big difference in the way they're facing
Really like the clip, the conclusion was backed by data and very honest. Very helpful.
I have been wondering about this for some time now. Thanks for the great video.
I did this, but instead of using misters, I used running water and caught it in a catch-pan and recycled the water. Month over month, I dropped at least $20 off my power bill. And this was during July/August, hottest months in Florida (not to mention the humidity)
One thing you didn't mention was how long the unit ran to keep the house at the right temp. If no mister, and the compressor runs for 80% during the day, and with mister runs 60% during the day, I think that also makes a huge difference on wattage consumption.
100W difference between mister vs non-mister is one thing, but reduction in run time over the course of a day is another.
This one is interesting. Your method is probably the worst way to use water on a coil. As the water evaporates, the minerals stay in the water and become more concentrated. Eventually, very concentrated minerals will be deposited on the coil.
Determining energy savings by comparing the electric bill is very inaccurate and should not be trusted.
I will be publishing a video on indoor air performance in the near future.
GFM
I think it should be explained that there is a difference between the sensible heat of water vs the latent heat of evaporation. Big difference.
Korishan Excellent point. And if people are worried about mineral buildup then just install an ice maker filter in the line.
Korishan whenever the condenser temperature is lowered the evaporator temperature will also drop resulting in faster cooling inside.
These type filters are not designed to remove all minerals from water. They are "treatment systems". When water evaporates, whatever is in it is left. That means deposits on the coil. Even if you put an RO filter in, you are then faced with pure water. That may sound good, but pure water is quite corrosive so then you would have a damaged coil.
GFM
When I worked in the telecom business, I've misted the data center or computer room condensers when we'd lose a fan motor, and could keep running until the repair tech could come out to change out the motor.
Thanks! Very informative. I was seriously thinking of buying that $200 misting kit but I'm glad I watched your video. I'll just make sure the area around the condenser of clean and no grass, weeds, or grass clippings get in there. Maybe occasionally spray some water into the condenser on a very hot day especially here in Houston, TX.
Thank you saving me time and money ! Almost bought into the product
I once had an process cooling and dehumidification installation that incorporated a l5 ton Trane condensing unit. One of the accessories that was spec’d for the condensing unit were evaporative pre coolers for the condenser coils. These were swamp cooler like modules attached to the condenser coil inlets, and used to make the condenser more efficient by pre cooling the condenser entering air temperature. It actually worked, until the calcium and hard water deposits that were left behind ruined the condenser coil. You basically turn an air cooled condenser into an evaporative condenser, which is more efficient, and will run with a lower condensing temperature, thus a lower amp draw to run the compressor. It’s fine as long as everything is clean, but once scale starts to form, the efficiency goes away.
As with so many "efficiency upgrades", the devil is in the details.
GFM
I live in Altus, OK and I have a coworker who used a sprayer for 10 years and his system is still running. The water is very hard and he has a filter on it. So the 'expert' has little knowledge on this procedure. I had a system built in 1984 and used this and cut my bill down by 100 dollars per month. The system worked for 8 years until the motor and blower went out.
This is exactly what I wanted to find out. Thank You for DOING IT!!
Best video/test yet! Thanks for the good info! Finally putting this to rest! It's just not worth it!
Thanks for the support.
GFM
I’ve seen several videos made by homeowners who don’t know how the hell an a/c works demonstrating their mister systems and claiming it saves them all kinds of money. It’s good to see someone that actually knows what he’s talking about make a video that shows actual numbers.
JD. It doesn't matter if you understand the principles of AC or not if you notice that the utility bill goes down after you try it. On the other hand the home owner might not realize the condenser fins are becoming crusted with calcium until a few years later when it becomes very inefficient.
Most new window units splash the condensed water onto the coils, this increases the energy efficiency ratio (EER) but at the expense of the coil oxidation. I typically drill/tap a drainage on these units so that they may last without premature weathering.
@@DarkLinkAD why are you bothering changing the way it's designed to function, condensed water does not have the calcium and mineral deposits in it that tap water does.
@@44hawk28 It absolutely does. Any pool of water will collect minerals and accelerate corrosion.
And my A/C funtions perfectly well, at 42F on a 98F day.
@@DarkLinkAD yes water will collect minerals. But can freshly condensed water, just like distilled water as far less concentrations within it. Perhaps you don't understand but water that sitting on the ground where there's a hell of a lot of minerals and water that condenses on a fairly clean object are in two totally different environments or perhaps you believe the calcium sound of thin air when water condenses.
I had an older unit that I was trying to limp through an incredibly hot summer. The unit was having a hard time keeping the house cool it was so hot and the unit was so old.
The water misters did help the unit maintain temperature inside the house which it wouldn’t do without the misters. Now the outside temperature was hitting around 105 and did so for about 2 weeks.
So in that extreme of conditions it might work a little better, but fortunately, we don’t see those conditions that often.
At 2 minutes 40 seconds you said what I was waiting for.
Number 1 son is selling everpure water filtration along with other HVAC services. After some time with this company, he has noticed the filtration systems are not performing as promised.
I would think, if misters were beneficial to the condenser, manufacturer's would have installed them years ago.
Great subject and video with lots to think about.
Consider if, as a manufacturer, I could increase the efficiency of my air conditioner by 20% just by adding this product and not have to spend many thousands (or millions) on higher efficiency compressors, fan motors and coils. I would do it in a minute. Obviously, it does not work well.
GFM
Great video. Thank you for being objective about everything. I see now that this would not be worth the detriment to the system. I'm in Florida near the water and everything likes to rust so added water would really exacerbate the problem.
I wonder if you would achieve similar results by directly cooling a six inch section of the AC pipe directly with slowly running water. The used heated water could also have great benefits for use in a nearby small underground irrigation system. Another variation of this theme is to cool a small section of the AC coil with the water using the water supply line that feeds the house. There is lots of water usage in a typical house during the day from flushing the toilets, using the sinks, washing machine, taking showers, etc.
I just spent 4 hours removing the hard calcium crust on the coil fins of my 4 ton a/c condenser unit that had a mister installed two summers ago. I used a 2 inch paint brush to paint on Muriatic acid full strength to soften the crust and then went through 3 plastic fin combs scrapping off the built up. I followed that up with a strong foaming coil cleaner and lots of water. Here in Oklahoma City our water has a lot of dissolved solids and by the way I used a calcium in line filter for the mister and changed it yearly. My advice is don't install a mister on your A/C condenser unit, you're asking for trouble.
Well, it's a good idea to clean the AC system once in a while, and 4 hours does seem like a sunday project but not too bad... Vinegar is what is used in bathroom cleaning products to dissolve calcium deposits, if you get one of those soap hose mixers for car wash and put vinegar there every few weeks, you can let your misters to do the work for you.
The bottom line is the misted water evaporates, cooling the lines in the compressor.
Same as evaporative coolers from 60 years ago.
Since humidity is not a concern outside, this might be worth something but, you might save a few bucks per month but you get the chance to build up mineral deposits in exchange.
I can appreciate the decision to blow this idea.
Thank you for making this video. You broke it down for people to see what is really going on with these mister kits. This may be worth using in parts of the country where the air is dry but anywhere else it appears to be a waste of water and money for a kit.
Welcome
GFM
The only flaw I see in the test and math is coverage of the misted air, discharge temp change and run time. If you reduce your run time by an hour per day that is also a savings of not using any electric for that time at all. That is not only the condenser, but also the evaporator fan at 200 watts or more for that savings period.
If that savings is enough to offset the water increase then it's a plus. Add in the treatments to clean the coils monthly and your time... Maybe a wash, but personal time vs TV watching is less electric usage.
#1 if you bought a spec house, everything in it is cheap and inefficient. Get in that attic and add some insulation. Add attic venting, add solar fans, add soffit venting, add a wrap or two to the A/C ducts, cover the evaporator with a wrap but make sure you only strap the insulation in the service side.
Next service your A coil yearly. Imagine one filter worth of dust getting into the A coil. If you haven't cleaned it in 5 years it'll look like a shag carpet.
If the envelope of the house is crap, the AC will perform like crap since it'll almost always be clogged... BTW most filters don't last more than a month, I don't care what they write on them.
Can a mister system work on an already inefficient AC? I believe so, but you better help it all you can. 50°F discharge air flowing through R4 duct may pick up quite a few degrees in that 140°F attic then come out as 65°F air at the register.
This video shows a far superior AC than most viewing have. I do still stand on the run time statement. Very good math, just overlooked an element.
This right here. He completely disregards run time
I would think it would add cooling capacity on hot days when humidity is not excessive. Additional capacity might be more valuable than energy savings when your system is slightly undersized in extreme temps. What is your opinion on that gfm?
Jim Damiani I plan to use this system exactly for this. The outdoor temp can shoot upto 45-50°C while is AC unit is only rated to run upto 43°C, so this system can possibly help me on those super hot days.
Your opinion, " leave it be" is my exact sentiment. You are one of the smartest guys.
Great video.
OUTSTANDING VIDEO even after 5 years
The unit in this video also looks pretty new and nice. It's probably operating pretty efficiently already. But if it was an old POS that wasn't efficient, a system like this may have more of an effect. Just a thought.
Probably less efficient, since the coil fins are probably full of dirt, so the water has smaller surface to evaporate on.
Valid point. However, in that case, cleaning the coil would be a much more effective way to improve the system's efficiency than modding it anyway, and therefore should come first.
The delta T in a coil that is greater than 20 is a very good system.
Or you don't have good airflow.
Water bill goes up now!
This analysis is completely ignoring the amount of time the AC unit is running. Misting the outside using makes the exchanger inside the house colder. This cools the house faster, which allow the AC unit to run less time overall. So, an AC unit that is not running is infinitely more efficient than an AC unit that is running.
Here's how I know this to be true. Yesterday, the temp was in the upper 90's where I live, and the AC was not keeping up. So, I went outside, and "misted" the coils with a hose. I came back inside, and within a few minutes, the temp in my house dropped 2 degrees. A few hours later, the temp was high in the house, misted it outside again, and the temp dropped again 2 degrees in the house. This tells me that misting the outside unit kind-of "supercharges" the AC. On a regular day, it would allow it to run less often.
You didn't take that run-time into consideration at all..
Your condenser may have been dirty...
The outlet temperature didn't change at all in his test so it doesn't matter how long it runs because it will take the same amount of time to do the job and if your method worked people would be using it all over the world. Systems that work right don't drop the temperature 2 degrees in "a few minutes". I don't know what your measuring but I trust this old guys expertise over your one test with no documentation lmao if you have a for example a 3 ton or 36k BTU air conditioner you can not get more than 36k btu out of it by getting the coil wet. It doesn't work that way sorry.
@@mr.monitor. what are you calling the outlet? Just trying to get my head around your response. Also, another thing not taken into account is outside temperature. No test is performed here to determine if it might be more effective closer to the 100 F outdoor temperature mark. Just thoughts. Interested to see your response. Thanks!
@@UncleMartin by outlet I'm saying the wet bulb temperature of the air coming out of your ductwork basically. Measure it before and after misting the outdoor unit;it won't change much if at all. If you turn the ac on and check temps keep in mind it takes at least 20-30 minutes to get the base temp. When a coil is wet the head pressure will drop a lot and yes will decrease the amp draw...but it will also have a hard time sub cooling(I know I know this seems backwards but its not) the now lower condensing pressure/ temperature of the refrigerant which leads to a cascade of events in the metering and flow of refrigerant that pretty much balances out anything being gained....its not saving you much if anything.
Perfect video. You covered all the bases. Humidity, calcium build up, Rust on the unit from the water.
Why would you get rust on the unit? When it rains do you get rust on it?
Many thanks for your test. Like you I find savings that slight not worth the risk of mineral buildup. Also, that water might be better used-and harmless-sprayed to cool down brick walls and hot asphalt. Cooling around your house should make cooling in your house cheaper.
Interesting. Thanks for making this video. I wouldn't bother with a water sprayer either. However, this water spray system may possibly be a little more effective than it looks. I say that because this water spray system may reduce the supply air temperature, which would mean that the AC wouldn't have to run as long to cool the structure, so there may be a little more savings there. Also, if it was hotter outside, there may also be more of a difference.
The theory of this thing is the atomization will evaporate the water. I kind of got a shower when working with this thing, so the humidity must be much lower for it to work well.
GFM
Good point. I'm just saying that this system may lower the supply air temp a little, making the efficiency improvement a little bigger than it looks. Still wouldn't be worth it though.
Avery Alexander Having your system run less sounds like a great benefit but it's not. The less the ac runs the less humidity it will remove from inside the house effectively oversizing the unit. Couple that with any upgrades done previously like new attic insulation, new energy efficient windows etc and very likely cause humidity issues.....
I highly doubt that a water spray system will reduce the run time of the AC enough to cause a humidity issue, especially since a colder coil will condense more water as the system runs. But good point.
seems to me the only logical place for a mister setup is the hot and dry desert areas, Arizona is a good example. next problem, how much water do they have to spare?
Couple of questions:
1. Would it be possible that the misters also caused an energy savings through reducing the overall cycletime that the condensor is on and running?
2. Even in high humidity areas, where the mist wouldn't evaporate, could the fact that some of it would still be pulled against the coils as water droplets still have an impact on the coils cooling?
jeremy baumgart
1.) It's unlikely to save you money, the difference you will paying for water
2.) Google evaporative cooling and no with high humidity means less water will evaporate thus less water carrying away heat.
I think you are picking nits here. The possible efficiency increase is very small.
GFM
JB, the cycling is controlled by the thermostat inside the house. Misting either makes the unit more efficient at cooling the house or it doesn't. The cooler water should have a positive effect on condenser temperatures no matter what. The heat of the condenser will cause the water to evaporate.
jeremy baumgart
I think you are right. Part of the advantage was missed(mist, nerdy pun). If the outside temp is lower it also means the inside is as well, so the inside thermostat should trip it off sooner due to higher heat transfer bringing the temp down faster. Also it appears the misters could be more effective producing an improved gain.
In the end I believe this will ruin your condenser due to corrosion and hard water buildup, so I wouldn't do it long term. A dedicated heat exchanger designed for it could be made though (cooling tower). The cost is why you won't see that done commercially for residential sized units.
Freddy McIntire, I don't understand what you are trying to say. I've heard of superheat and sublimation, but never subcooling. What is it? How do you measure it?
Another very nice video. The big benefit would be a reduction in head pressure during an exceptionally hot day that could make the unit lock out on a high head pressure. Also the electric company would appreciate the lower kwh use on that very hot day. However it would take many, many people doing it to make a difference. When I ran a very large chiller, the electric company would call me to see if I could reduce the load. I did but the people in the lab building were not happy when the temps went from about 72F to 80 plus. Also need to add water cost into the cost factor. Thanks for the video's.
Waterman one I'm sure the power company would love it but not your water utility...
The dew point at the time of use will have an effect on the efficiency. Anything above a 65° dew point, pretty much eliminates any gains. However a water curtain running down the coils does have a major effect by using the temperature of the incoming water and not the evaporative effect of a mister. I run a column of water down the condenser on my four ton unit, adjusting the flow to allow a ten degree rise of the incoming to outgoing water. Right now it is 96° outside and 78% humidity. Water on vs water off is 34% reduction in input energy. The outgoing water is drained to my large pond. No mineral build up at all. Last winter we used it on cold snaps to add heat as well.
Setting aside all the potential issues related to spraying the condenser coils (legionella, coil corrosion, mineral buildup) - I'm not so sure that this one's that easy to poo-poo away. Saving energy is always a huge plus, but even putting that aside, a system like this will give the overall system a performance boost on super hot days. In the middle of summer here in Georgia, there have been times when my AC unit was having trouble maintaining the temperature - the unit would essentially run continuously just to maintain setpoint. Especially after a power outage or if it had otherwise not been running for an extended period - it would take FOREVER to get the house cooled back down on a 98 degree day. Manually (temporarily) spraying water on the condenser coil to help it shed heat has always helped the situation.
It's incorrect to assume that on a very humid day a system like this would lose ALL effectiveness. Sure, on a low humidity day, the air itself is cooled before passing over the coils, but a MUCH larger transfer of heat takes place when liquid water evaporates directly off of the coil surface. So even if the humidity was at 90%, liquid water being forced to evaporate off of the much higher than ambient temperature coil surface ensures that there is still a cooling effect. Think about it, even on a crazy hot, super humid day in Florida, and even right next to the ocean, everything still quickly dries (the road, patios, decks, etc.) right after it rains.
Of course, the TRUE issue with something like this is what I "set aside" in my first sentence. Spraying water onto the outdoor coil clearly has a benefit - it's just that doing so is very likely to cause damage the system. Figuring out a way to get around all the mechanical risks is the key to making this work...
Growing up in West Texas, we used swamp coolers, I’m wondering if a shroud, using that technique, would cool the surrounding air without the mist harming the coils.
I know that I have ran water over the coils and as I started the air was hot. But once the coils got cooled down from the water I was spraying it was considerably cooler coming out of the top of the compressor. Those were my thoughts exactly. Just like in a fractionation plant the cooling towers have a huge water reservoir and water is used the same way to cool the process.
@@willwright3396 🎯
Thank you. I was sure considering this, since I live in Houston and my electric bill was ENORMOUS in June. But, I am glad that you did a realistic test. So, I will not do this now.
Now it's even bigger lol
I enjoy your videos and knowledge I gain. Not long ago on Ask this old House show they showed how an air conditioner condenser was used to heat up a pool via freon circulation somehow. Very interesting and my thoughts were why not do this for hot water tanks inside the home
There are several ways to do this. One is use a "superheat remover" on your AC. It is a heat exchanger that is connected to your cold inlet of the water heater.
Another is a designed "water heater heat pump" best used in southern climates. One more is an air heat pump that can be used to warm water or cool the structure.
GFM
Well, your test showed a definite improvement in the operating efficiency of the AC unit and you didn't optimize the misting heads or spray patterns. This could be done with rain water and a pump that is driven by a solar panel w/battery, as the pump would not require much power.
The point about humidity is valid in the context of ambient temps, however you also need to consider that the A/C coil is hotter than ambient temperature and therefore will heat the water enough to cause it to evaporate. Think about it - no matter how humid the weather you can still boil water and produce steam...well, the AC coils won't boil water but it will certainly still evaporate and improve the transfer of heat from the coil into the air. Also, the water can drip off the coils and provide cooling in that fasion.
If I was going to do this, I'd probably catch rainwater out of a gutter pipe. The concerns over damage to the coils are irrelevant with proper and simple maintenance, like cleaning the coils as needed.
I don't think he knows what he thinks he knows, or that there are things that he doesn't know, or that there are people who know things that he doesn't know.
Yep, and he can also up the AC efficacy by cleaning the coils/innter system out once a year.
Plus you could give the AC unit extra shade by placing a large beach umbrial over it. Or plant two trees near it.
Rain water isn’t a great solution for this as it’s likely not going to be as nearly as cool (relatively to the ambient) as tap or well water would be.
That being said… this guy making the video isn’t taking into account if the system is running less to achieve the same temps inside the house. In other words, if the temps across the evaporator inside the house are dropping, the air coming out of your vents is going to be cooler and the system won’t run as long. Not sure if there is any truth to that but it’s a factor he never addressed
The only real-life application where a mister system make sense is a large commercial unit that has doomed condenser coils. It can buy you a little bit of time while you get the budget to replace the coils or the entire unit. Excellent video, sir.
Do you think it would make sense for old commercial condensers in a humid state like Florida? This is the only company I've seen on the internet that promotes misting systems: smartmistsystems.com/ac-mister.html
Peter Valadez Florida is typically very humid so the evaporative effect is lesser than a dry area. Again, for a large commercial application where you are planning to replace the equipment; it might buy you some time. Typically, a commercial mister system would be a 1/2" copper pipe run along the outside of the unit with Ts and mister heads every few feet. The system is controlled by a solenoid valve that opens when the head pressure gets too high.
Good test, It’s obvious you know what your talking about, I’m in full agreement in your findings.
Thank you for sharing your knowledge!
Welcome
GFM
I did design my own setup using a small current sniffer to turn on the water to the nozzles that detects the AC unit turning on without physically being connected to it and it draws just a few watts when running but I am also using a timer so this thing only kicks in when the sun is hitting the heat pump directly which is for about 3 to maybe 4 hot hours a day then it tapers off as the sun starts to set. I f I had to give an opinion I would say that the air in the house feels a bit cooler but that could just be psychological. Just a side note: Your video was done very well covering this topic and is one of the better videos on youtube. Thanks for making this video.
Welcome. You are probably right about the cooler air being psychological.
GFM
flash001USA The inside air will be cooler. When the condenser temperature is lowered the evaporator temperature is lowered too.
I will be publishing a video covering that issue.
GFM
That's why you have to run a filter to make sure you're pulling garbage out of the water. We don't have calcium issues here so that's not a concern and as far as running this thing and damaging the AC unit outside that's not going to happen anymore then rain coming down from the sky while the thing is running and causing damage to it. I do understand where you're coming from but this thing only runs during the peak heat of the day which is only for a couple of hours when the sun is directly shining down on the unit outside. In other words I've got it setup on a timer and I don't even bother running it unless it's close to Triple digits outside.
The sun hitting the condenser coil directly will reduce the cooling system effectiveness. Your strategy might actually help with improving the cooling efficiency.
I can also save by raising the set temp on my thermostat by one or two degrees. It works everytime.
One of the best YT channels out there… 👍🏼🇺🇸
Thanks for the support.
GFM
You put into objective numbers what I had concluded subjectively . This is my 2nd or 3rd viewing of your channel New sub. 👍🇺🇸
Welcome
GFM
Anything that lowers high side pressure is good & the system doesn't have to work so hard ... If you don't believe me start your car turn on the AC & let someone spray cool water from the hose on to the condenser & see the difference it makes on the inside air temp coming out the vents in the car
MH, I should try that. Technically the evaporator is moving heat to the condenser through the refrigerant, so I guess you must be right.
Wrong, there is normal operating head pressure and excessive head pressure caused by several different factors. In a situation such as a fan not moving proper air across the condenser coil, (dirty coil, replacement motor of wrong specs, motor running in wrong direction-yeah i have found that, etc.) introducing water that is evaporating will effect the systems performance, but this is a band aid effect. the correct course of action is to insure that the system at both sides is operating within correct perimeters. condenser coil is undamaged, clean, and proper airflow over it. evaporator coil is clean, proper airflow across it. This will also include, compressor operating properly refrigerant charge within range, based of of proper airflow, sub cooling and super heat within manufacturers specs for current conditions.
If spraying water onto an air cooled condenser coil had merit, all the manufactures would have standardized it long ago.
I see it mainly as a way to get a struggling unit through a bitterly hot day. If someone really wants to try it, they might as well save the $60 and use their lawn sprinkler or even a hose nozzle positioned on a post nearby.
What are the capacitor and Victor trap for? Just to see who's paying attention? :-)
I agree Bill. It'll also probably help if the unit is undersized. And by the way, I love your channel. IMO, you have one of the best channels on RUclips. Keep up the great work!
Been there, done that. On a large commercial condenser that kept tripping out on high pressure in D.C., during a heat wave. It's a real "duct tape" type solution, but it got us through until my boss got money approved to replace the unit.
Perfect use for it. My system is leaky and 20 years old. I will be replacing it in the spring, but need to get it through this summer. I am basically doing the same thing with an old misting hose and turn it on each day. It is amazing the difference in how it is working, you can physically feel the air is cooler coming out of the registers & the unit runs much less often. I will not do it with the new one, but with every day being 90 degrees in NC & the hot sun heating up my attic, this has limped me through the summer nicely.
We use it on some Co2 racks usually get a 170/80 psi drop in head pressure it's controlled by a t-stat.
As an AC tech who has done this and also worked on evaporative cooling towers, I don't even want to get into the subject of water hardness and calcium deposits. What I do want to say, is when you lower the head pressure you will correspondently lower your suction pressure, and this will give you a correspondingly lower evaporator temperature, which can give you a little cooler discharge air. Not much, but some. Sometimes large systems would get away from us on hot days, and with hot rooms and hot outside temperatures, we would try to start a system up, but it would trip on high pressure. We would then run the system while spaying down the condenser coils until the rooms cooled. Then the suction and head pressure dropped, the load decreased and then it would run ok without water being sprayed on the condenser.
Thanks for making this video. I was wondering if that worked or not.
Great job! Also the cost of water must be considered.
Pretty sure mist wouldn’t run all that much
Could this improve the indoor split as well thus reducing run time ...just sheer curiosity at this point
This is a very good forensic analysis if misters are actually beneficial in reducing head pressure thus reducing amp draw on the compressor. I am not very keen on blowing city water on to the condenser coils because of calcium build up. I just put a stand alone high velocity fan blowing into the condensing units coils. I really dont know if it really helps because I dont have an amprobe any more or the correct gauges to see if that stand alone fan is doing any good. Where I live electricity is real cheap so I am not worried about that. All I am interested in is reducing the compressors head pressure to prolong its life. I am a retired electrician but over the years I have learned a little on how central air conditioning works.
I've seen the rabid know it all videos who never worked on a/c systems put down veteran a/c contractors who do not agree on this snake oil version of savings, when I rinse a coil on a hot day the indoor area feels clammy while the coil is wet, what about premature rusting and I'm sure every one of these guys have a water treatment setup to prevent any minuscule scaling on coil, does the mister price win over the paltry savings and extra little water usage, some of these also want to build an enclosure to keep the sun off of condenser no such thing as high head pressure on a covered condenser, JK, some companies void warranties if they come upon a condenser with a bad compressor that has an enclosure, but what the hell do I know about a/c systems in my 20 yrs of doing it.
muniznick was there a question somewhere in that block of text?
Jonathan Roeder - ha ha ha ha. I thought the same thing!
A wet condenser shouldn't raise the RH in the space..., am I missing something?
Outside in normal elements not the same as continuous. ever see a condenser get continually marked for territory, as in pissed on daily by the family dog? wrecks it, granted piss is harsher than city water, but natural elements are much softer than this misting system idea.
It was nice of Hank Hill to make this video
spot on
Nice test! A lot of window AC units have actually done this for a long time. The condenser fan at the back of the unit has a plastic ring around the blades that picks up condensate water and throws it at the condenser coil to help it cool. All 3 of my window AC units do this, even the 30 year old one I found in the trash. Someone actually drilled holes in the bottom of it, which rendered the water mist cooling ineffective. However, the unit did seem to perform better when I patched the holes. Obviously window AC units are pretty limited on how big the condenser coil can be, so that might have something to do with why it's so effective. Anyways, I thought you'd find that interesting
Condensate is pretty much mineral free (As long as the evap coil isn't coated in buildup) so it's no harm no foul to get the advantage of evaporative cooling to help the condenser coil. Split systems though the condensate has to travel quite a distance and may not even exit the house on the same exterior wall the condenser coil and compressor is on, hence why it's not used on residential units. Plus with the way most split systems suck air through the coils no cheap and easy way to sling on the condenser coil and even if you did then dust and dirt would potentially build up and turn to mud (a problem that even window units can have if not maintained).
Large commercial plants do use water spray but they treat the water and those units are often different in layout.
@@Cragified Good point. The water mist system definitely makes window AC coils get dirty faster, but I haven't seen it cause corrosion or buildup since it's basically distilled water. But I think for most people it does more harm than good over the long run since hardly anyone bothers to properly clean their window AC units.
These misting systems are very dependent on humidity. Just like the patio ones that make sense in a dry area like arizona where the humidity is low but not here in Alabama where its high your just going to make things worse. Also the hardness of the water is a big deal as that will clog up your system in no time. So Desert environments maybe, but else where your wasting your money and in the end its going to cost you in repairs. Great video test of these, thanks!
The water is just another medium for removing heat. It will lower head pressure and it will remove heat. Evaporation is one factor. The temperature of the water is another. The temperature of the water will lower the air temp at the condenser. It will not affect the indoor humidity in any way. If it was an emergency like an old unit that can't remove heat anymore then its a great solution until you can replace it. On a new unit it will accelerate corrosion and shorten equipment life.
he was talking about outdoor relative humidity, if it's real humid out, then adding additional mist will do near nothing.
Michael Paddack ... and it messes up the coils and it rust out the body and makes a general mess and it is not recommended. Experience has taught me that snake oils do not work and I'm an air conditioning technician. I'm not a God I'm just saying you need to keep this simple and not mess your coils up
Roger Lund I don't disagree with anything you're saying and pretty much said that at the end of my post.
throttle bottle 60 degree water wouldn't lower the head pressure. Interesting.
60F water would sprayed directly onto the coil for water to gas cooling, but as a mist with humidity at +90% or raining lol.
evaporative swamp coolers are a good example, they don't do any good in humid areas. non evaporative types using cold water through a radiator or heat pump with liquid to gas condenser will work good. but then you have many more failure points and need pumps, filters, glycol antifreeze, etc.
You’re going to corrode you condensing coil super fast doing this, I’ve seen it a few times before, I’m a refrigeration and air conditioning mechanic
Is this true even though condenser coils are designed to be used in high humidity environments? I'm an engineer and scientist.
doesn't rain outside?
@@21boxhead Rain does't have the same minerals and hard water deposits that city water has. Rain also does not come down each and every day.
I agree with the whole calcium thing as well. That was the first thing I thought when I saw these things. Hey can you make a video on the difference in energy,efficiency, and/or comfort if you leave the fan on instead of auto. Iv always felt that when the fan is on, the temp. is at its best comfort. But how much in energy is the difference and does it matter on which metering device. If you can. But regardless thank you. Glad your still makeing videos.
I wonder if this would affect the duration of time the unit would have to run to cool the house, that might provide some additional savings?
With the lower air temp that the AC unit is passing through it you are also going to have a lower run time that will further increase savings.
....and the fins will fall off.
you did miss one important factor!!! the temperature of the air blown inside
I believe if the air would be colder that would mean the unit runs less time.
Do you mean inside duct temp? If so, how are you planning to reduce that temperature?
GFM
grayfurnaceman
yes the duct output. if that will be lower, means the house will cool faster, implying less run time on the unit
Less run time equals inefficiency. They don't become efficient short cycling. The longer it runs the more efficient (20 minute cycle much better than 5 minute)
The run time may be reduced, but I believe it will be minimal. I will do a video to test.
GFM
You are , of course, correct. However, the decrease in run time is probably quite low. I will be doing a video including this measurement.
GFM
certainly an interesting concept. The industrial units are MORE cost effective due to the scale of the system.
Always hidden costs of time, materials, water, cleaning minerals on coils, water filter (which won't get it all).
We had a site not willing to replace u units just yet. But on hot summer days coil efficiency was lower Than it should be. Units would trip on high head pressure.
We installed misters there to keep it tripping out.
While you can achieve sub ambient temperatures through evaporation, you lose efficiency over time through scaling of the coils. In addition the cost of the water and if used descaling system and maintenance.
The commercial systems use a waterfall with recycling their water, water treatment and coils designed specifically for water sub ambient Cooling.
The calcium, thats a big problem. GOOD ONE.
Most misting kits have calcium filters, this guy either bought a shitty kit or ignored the fact and is trying to seem smart
I think there are more sides to this story, but I you did an excellent job jumping in and gettiing this rolling. Thanks!
Thanks for the showing the actual number so we can see if it is worth the hassle. We have nearly 0% humidity so I think it would be more effective here. But, if you even triple the cost savings at 21% I might get $10/mo. Now that is closer to being worth and it since my air runs 8-9hrs a day I might even get a bit more. HMMM!
Ya but what if you had r22 spraying out from the magic mister? Get that condenser coil nice and cold then I bet!
Kind of expensive and illegal.
GFM
grayfurnaceman Also R22 isn't environment friendly.
S NS5, It certainly would be over kill.
I'm calling the police 🙄
It's illegal to dump R-22 but I don't know if anybody has ever gone to prison for that offense.
Oh my god!!!!! Hard water !!! Permanent damage!!!! Failure in electronics!!!! Mmmmm is this a good idea 🤦🏻♂️
The newer Mistbox has a filter for the misting water...
I have a shade structure to keep direct sunlight off of my ac unit mainly for earlier parts of the day when the sun is directly over plus misters. of course i have an older system thats quite old but still cools pretty decent.
I live in the hills in LA and while it uses water, the unit cools my home faster and maintain a lower overall temperature. My house is older and the upstairs has no insulation just beams. I guess I am lucky because those mini swamp coolers work too
If misters where something that worked and delivered a 20% savings, AC manufacturers would add it. Manufactures would have there "marketing"demons touting it.
Mr Krasker yea right this is standard practice in Vegas buddy
Evaporative cooling could certainly help in an arid climate to boost the efficiency of a closed system like this. The reason that AC manufacturers don't do this or implement it is because they have little financial incentive to. They don't pay for the AC bills that customers incur. If they added a system like this, their units would be more difficult (and expensive) to install, and they'd have to warranty more parts, which they also don't want to do.
The real problem is total cost of ownership. Customers aren't savvy enough to know how to forecast their usage effectively, and thus wouldn't be able to understand if something like this would make sense financially. I see builders foolishly installing these condenser units on the sunniest spots of the properties out of convenience for them, apparently not caring that it will then get extremely hot during the afternoon when the demand for cooling is at its peak while the heat rejection part of the system is also in direct sunlight, and therefore is at its least efficient.
Same thing for both parties: lack of craftsmanship and care for their customers or for the environment.
Michael Horsford
Do they just mist water out in front of the condenser coil, or are they using pads like a swamp cooler has?
The only systems I've seen that both work, and don't damage the equipment have some sort of water panel, basically a swamp cooler pad, in the air stream before the condenser.
Industrial ACs do this. One problem with such permanently hot and damp systems is that dangerous bacteria and fungi thrive in those conditions so the units have to be periodically inspected and treated (chlorination, peroxide or other) to prevent potentially severe and lethal outbreaks.
I was in The Bellevue-Stratford Hotel in Philadelphia at a ham radio convention at the same time as the Legionnaires' had there convention. The outbreak of Legionnaires' disease killed something like 30 men, quite a few people got very sick. I had my wife and 3 month old son with me, the CDC and Philly police came to my house and talked to us, we never got sick.
I am in the Phoenix Arizona area, 115° low humidity. These misters work really good out here in the desert. Keeps my house cooler much easier.
Another thing to consider, some ice machines run off a water cooled condenser for 10 to 15 years with no significant scale build up. Scotsman, Manitowoc and Hoshisaki all make water cooled units. Same with some hydronic systems. Will think about this for a while!
you know there's "heat pump/geothermal" condensers using water from lake/pond or loops in ground/wells right? the down side is they have many more things to go wrong, like pumps, filters, controllers, balance valves the risk of freezing in cooler climates and heat pump mode. so you have to run and maintain glycol in them.
i'll avoid commercial size "chillers" and towers :)
Melvin292 water cooled condensers do not experience evaporation which then causes deposits to accumulate as water disappears
I'm curios as to what the power factor is with both dry and wet coils. Or does the run capacitor on the compressor take care of that?
Power factor is very much overused. I would have to say that there would be no difference if the power factor was included.
GFM
I have done the exact same testing myself, with much different results. The only difference is that you used an insufficient amount of water to be effective. My test was conducted on a unit in full shade on a 100 degree day in west KY. (humid) Like you, my unit was running at 10 amps. With a generous amount of water the amps dropped to 6.5 or so, a huge improvement. I could hear the unit unload as the pressure decreased. Environmental conditions can and will make a major impact on results, therefore the savings will vary from day to day. But the theory is absolutely solid. Performance may vary with your experience. LOL
You have not watched the series. You have also not tested delta T of the indoor coil.
GFM
Thanks for the video. Just wondering isn't the job of compressor is to raise the temperature higher than outdoor ambient temperature to release heat? And therefore it'll change the subcool/superheat?
It is the job of the compressor to raise the condensing temp above the ambient. Subcool and superheat are not directly related to the condensing temp.
GFM
I've always wanted to try having a swamp cooler pointed at the condenser to see how things would go. I know in the Arizona desert this would keep the condenser and compressor much cooler which would keep the AC unit running more effective along with the compressor lasting longer.
You will find the power used by the swamp cooler and the water usage will far exceed the savings.
GFM
I used a garden hose with a spray nozzle ti test mine. I only saw about a 6% reduction in running watts in the morning with an ambient temperature of about 85 degrees F and fairly high humidity. Testing it in the late afternoon after the ambient temperature was over 100, I saw about a 30% reduction in watts. We’ve been running with a very low humidity in from about mid morning to evening so not sure how much the humidity helped vs the ambient temperature. I’m seeing running watts go from about 2000 watts in the early morning to about 2500 watts in the evening.
These work great in areas with low humidity. In high humidity areas there is nearly no evaporative cooling capacity, so very little power decrease is noticed.
Start & Stop The Water Spray System According to Humidity in Georgia Thats How I Do It
Did you measure the total subcooling of the condenser? I'm curious what it did with that to affect overall operation and capacity.
I did not. I may do an additional video that includes superheat and subcool.
GFM
Ok, you made an instant test, but I'm pretty sure that the unit is going to cool the room faster because liquid refrigerant is going to be cooler getting a better efficiency. Probably the compressor is going to work less time. I'd try misting the system for a whole month or more and compare to see if power consumption has really gotten lower. Thanks for your videos.
It depends on your climate and what the humidity is outside. Places like West Texas during the summer months it really does help reduce power by about 20%
A large industrial building I work at installed roof top misters and our roof heat load was reduced by about half. This reduced our electric bill by about 20%. A waffle hut in Alabama installed a lawn sprinkler on its roof and they told me it reduced their a/c bill by 30%. Of course it is controlled by a computer. I. would like to understand how must any added roof maintenance may have been.
Thanks for your real world evaluation of a/c condenser coil misting.
The use of misters on a roof can be effective in reducing roof load on A/C systems. However, when large drops in power usage are listed, I am always skeptical. Power bills are notoriously unreliable in determining drops in usage as no month is the same. It also indicates there is a problem with insulation of the roof.
GFM
Thank you!
I convert 1 hose mobile air conditioner to 2 hoses. I also make small hole - the condenset water drops to the coil.
That same principle is used in newer window air conditioners. The bottom of the case fills up with water and the fan slings water onto the condenser. They also fill up with algae too if you don't put an ounce or so of bleach into it every now and then.
That system is used mostly to get rid of condensate. With a little help on head pressure.
GFM
may I have an idea of the ambient temperature and relative humidity. because the humidity affects the effectiveness of the spray making it easier or harder to evaporate and the temps also affect how fast the water evaporates too. also, I would like to know if the ac was running under direct sunlight this misters thing will work better. Thanks
Humidity and temp are shown at 7:30 in the video. As for sunlight, there is virtually no difference in operating temps with or without full sun.
GFM
Smart, well done video, keep up the good work. The Comments are very good also!
Interesting. Our electricity is 20 cents a kw/h and our 1988 unit draws more power than the one in this video, so might be worth it. One benefit not mentioned is the reduction in how hard the compressor and motor have to work and effect on lifespan. My 30 year old machine might like a bit of a break.
Great vid, so we don't really save much power with the mist, my question is, does it make the unit cool the house any better, despite the cost?
There will be some increase in capacity, but I am not sure how much.
GFM
Calcium is a dissolved solid. The only way to remove calcium is reverse osmosis or ion exchange (water softener). When you use a TDS meter you will see from softened water that TDS is the same. That why it's called ion exchange. Good decision not to keep spraying that nice Trane. It would absolutely clog the coil eventually. This was an awesome video. Thanks for sharing the research.
Welcome
GFM
Wondering if this would help the ac cool an area if ac unit is inadequate sized for room. Does it help increase btu?
The misting will not help. I would look to limiting sunlight entering the room. GFM
Great video and good job
Hey nice vid informative , thanks for this I agree let it B, but was wondering in the other side of things do you think by doing this your AC unit over time doesn't WORK as hard & we get longer life ???
If your A/C is charged and installed correctly, with normal maintenance, it will operate with 100+ degrees F ambient for a very long time. It is designed for this use.
What happens when you install misters is that you introduce an abnormally low head pressure that changes the hi side/low side relationship which can reduce compressor cooling and change superheat.
GFM
Is it possible that some of the efficiency of the misters is the result of the AC actually getting the refrigerant colder for the same/similar amp usage? My vents feel like they blow colder and the compressor does not have to run as frequently to keep the house at the temperature setpoint.
Even if the AC only uses 6% less energy while running, the total energy savings is still a lot more if runtime is also reduced by 15% (for example).
Watch the rest of the series. There is no reduction of run time.
GFM