Easy Ways to Lower HVAC System Static Pressure
HTML-код
- Опубликовано: 9 июл 2024
- HVAC Shop Talk is a RUclips channel & podcast that celebrates the guys and girls in the skilled Trades - especially HVAC. #hvac #hvactraining #hvactech #hvactechnician #hvacpodcast
Join the HST Discord server - / discord
Sponsors
Beckett Corporation - beckettus.com/product-categor...
Yellow Jacket - yellowjacket.com/
NAVAC - navacglobal.com/
Company Cam - companycam.com/
EWC Controls - ewccontrols.com/
TruTech Tools (Use my "SHOPTALK" promo code)
www.trutechtools.com/
Contact me - hvacshoptalk@gmail.com
![Skilla Baby - Misfit (Feat. Polo G) [Official Video]](http://i.ytimg.com/vi/IjsylSnNMyw/mqdefault.jpg)
That was explained great!
I agree low air flow on systems and oversized systems are common. Mostly returns undersized. new houses have more returns. My house has returns in all rooms and big one in hallway.
Good thing here in the south is that usually you can add a flex return to help out
Good tips thank you.
Adding a bypass humidifier will reduce about .15 wc. Be sure to check temp rise after if on a gas furnace.
So we find ourselves in this exact scenario. We recently got a Bosch IDS 2.0 5 ton condensor/4ton handler system installed in our 1980s home that had ducting already in the attic with one big central return in the second floor hallways ceiling. I think the handler is oversized for the return that we have. The return grill looks massive, but if you take it down, it curves into a much smaller choke point about half the size before expanding again to larger ducts. What happens now is when our Bosch goes into stage 2 fan mode which is set to use the second slowest tap available (ecm blower - 5 taps for speeds but only can use 2 at a time) we get a ton of whistling noises on that curved part of the return. I verified this by sticking my head up there while the unit is going and I can literally stop the noise by placing a filter or something on the bend part. You can also feel a ton of air rushing by so the thing is really sucking up there like a vacuum and the filter in the unit is brand new. The heating and cooling are not suffering however, but it seems the ECM is having to work way harder and we need better return flow. What do you suggest? Can I just add another 10" duct somewhere and tie it into the return by the handler? We are very handy people so it wouldn't be a problem. Ordered a static pressure machine that should be coming today to get an idea of just how far off factory max pressure we are... currently using a merv 8 1" filter at the unit in the stock slot before the coil.
Hello. Any update with your system?
I am having a similar issue. The HVAC company upgraded my system to a larger tonnage, and now with the system running I can angle out the filter in the return duct about 3" and let it go. It will snap back into the filter housing. They added a 2nd return filter under the indoor unit and changed the taps on the blower motor to the lowest speed but It still feels and sounds like a restriction. Annoyed!
Interesting. I didn't know about the supply and return grill options. Makes sense. Even if it only makes a 0.25" WC difference, it could put less strain on the blower.
It can make a huge difference when restrictive grills are in place. Take a look in older homes and you will see grills with 1/3” fin spacing. Look how restrictive they are compared to 1/2” spaced fins.
I was the customer a few hours ago who told the HVAC guy "Enjoy Your Day" When he said it was going to cost me an extra $3k to fix my static pressure after they wanted to replace my gas furnace, in a 2000 sq ft, two story home, for $6500. Cause F'k that! 10 grand on a new furnace? No way.
I think you underestimate the price of equipment nowadays. Especially high efficiency ones. Inflation is up and up. And Covid fucked a lot of manufacturers. Plus you guys don’t ever think of how much hvac techs make. They can’t do cheap labor or nobody would make money. Instead of crying about prices learn to do it yourself
Guess you don’t know how much it cost to run a business these days. You probably went and bought a 80000 dollar truck and didn’t whine at all. Also if you need ductwork to fix your issue then yes it cost. Typical homeowner that’s knows everything.
@@robertlamey7612 and you sound like the customer that keeps these businesses afloat 🤡 … got a 2nd quote for $5500 for everything… and they gave me a Lennox furnace while the 1st company was giving me an off brand model.
Wow, that sounds like a shade tree price. You get what you pay for. All installations are not equal.
Brother and sister-in-law have a three day heat wave of 106°F AC cannot keep up cannot satisfy. All I did was remove all the grills that you just mentioned & remove the return grill thrown in a cheap Home Depot rock stopper filter after that on 106° day it was able to satisfy bring the house down to 73°F. Of course you can’t remove all the grills at your customers house and tell them that’s how it Hass to be for it to work right 😂
That stuff can make quite a difference.
1 return air duct and grill is always a red flag if your home is over 1,000 sqft!! In my area I'd say half of the ducted systems we replace need a 2nd return air duct and grill installed. Far too many homes only have one 14" or 16" return air grill for a 3, 4, or even 5, ton system.
Static reading was .8 should be .2 according to hvac company. Want 15k to redo 1980s ducting in a 3 bedroom 2 bath ranch home. Can I just add another supply to reduce it? House has plenty of returns. Returns are on the floor level though would moving them up help as well?
Often you can get needle nose pliers and just bent fins open to almost double the free area. Iv'e had to get a utility knife and cut off the 40 years of paint on the fins.
A sure sign of low air flow is the filter cover or fan compartment door slams shut or filter gets sucked in to the filter rack. Just starving for air.
High pressure areas of the system are the most important. Properly supply and return plenums with low TEL take-offs can reduce your TEL by 50%!! Turning vanes, radius elbows, etc.....Most important IMO.
Thats true, those items can make a world of difference. I remember reading manual D and seeing the big difference it made when a curved el with vanes was used instead of a squared off 90. Crazy.
@@HVACShopTalk I decreased the static on a customer the other day by .15 by just changing the dead head supply plenum with a radius plenum and transitioned trunk takeoff (larger off the plenum on the bottom side).
Is a fiberglass merv 2 filter safe to use as far as stopping enough things to not effect the coil/ blower?
That’s what I use and my coil is clean.
Thats what I used for 20 years and just installed a new system. The removed air handler coil was very clean.
Great video. I abhor those fíltrete filters. I don’t call them filters, they are air flow restrictions
Yea, they are so bad. Stinks that people see them as the best
Well, the pressure drop vs face velocity curves are published for those filters. Why don't you look them up and show us how bad they are? Or, maybe they don't have particularly high pressure drop and actually have far more filter media. All the data is out there, encourage you to look at it.
What happens if you don’t use a return grille at all? Is that a problem?
Yes it will pull to much air causing low draw from the other R/A grills.
@@Breca interesting, so it would pull too much you’re saying?
@@christianf5131 It will pull too much from that room and less from others leading to imbalance of comfort between rooms.
Can too high of static pressure cause the condensate not to drain while the unit it running? I have a 3.5 ton Goodman packaged heat pump, for the life of me I cannot get the unit to drain while the blower is running, once the unit shuts off, I get a big gush of water out of the p-trap outlet, the outlet of the trap is about 4 inches below the base of the unit, the piping is 3/4 inch. The trap remains full of water and no air is being drawn into it. The last maintenance I did on it last month, I noticed that the blower and everything in the air handler had moisture on it and there was about 1/4 inch of standing water in it. My supply trunk line is 14 inch that is split into a Y feeding 2 plenum boxes in the crawl space, each box spllies 5 vents fed with 8 inch flex. There is a single 14 inch return with a 14x20 filter, all vents are in the floors including the return. When the unit fires up, I can hear the ECM ramp up gradually to high through the return wiuth the filter installed, I tested it for a minute or 2 without the filter and it's quiet then. Any ideas?
Yes
Return too small , needs a16” and 8-10 on return . The grilles and supply 16 or 14 and 10 at least. Adjus5 blower speed. Recheck charge❤
I had exact same problem but i have 2 12x24 return grates and i didn't have a ptrap. I've dialed down blower to minimum speed and installed a ptrap that is 3/4" thats 5 inches below handler then back up 2" then down 3". Now my ac drips when unit runs. I also installed UV light and that made a huge difference. I made mistake of installing too large system. I should have a 2 ton instead of 3. My ducts are too small.
I am not an ac man but I had the same situation that fldave612 had. The solution I found was I altered the p-trap angle of the pex pipe leading out of the evaporator pan. the p-trap that is on the output side of the evaporator is cap on the side closes to the out put of the unit so I can do a clean out. On the other side I made the pipe of the p-trap go above the output of the pipe coming out of the evaporator leading out the room. I then made sure the furthest side away from the cap ptrap had the pipe going vertical was uncap and higher up above the evaporator pan this allowed the pressure of the evaporator to push the evaporator water or condensation out. I then made sure the pex going to condensate pump was angled at a 10 percent angle you may had to play with this angle like I did trial and error.Last I had to take the cover off with the ac unit turned off and clean all the algae that had built up in the pan because the inept ac installer did not do it right. That is when I took a wet vac and blew all the crap in pex drain lines back in the evaporator and use water and drained the crap back out. You will know it has been successfully done when you see clear pex pipe connection and look at the condensation pump container water when it should be clear water. I brought a p-trap fitting with clear pex to spot the crap of any . I hope I have help some people out there by reading this I learned this by reading and trial and errowing this?
Home Depot morons will sell them the best filter known to man and then their unit will freeze up or they’ll lose the blower motor or the TXVL O L❤
Do like to share this video please.
I beg to differ on a couple of points.
1) restricted air flow will not "strain" a blower motor, nor will said motor "work harder"
A blower motor is technically a pump. If you put more product in a pump, it works harder. If you put less product in a pump it doesn't work as hard.
So...........
More air = more amp load
Less air = less amp load
By restricting air flow for a blower motor in a hvac unit you will move less air volume that is required to cool motor. This will in time burn out the motor.
And along with motor running hot......
Restricted air flow(high static pressure) will create a scenario whereby the heating and cooling cycle times will be lengthened (temperature rise/drop will not stay in designated range) which will use more energy = more operating $$$.
Feel free to test this theory with a quality amp meter all skilled hvac technicians should own and have on hand.
2) although playing with filter "types" may improve the static pressure, an easier more effective repair for any home handyman/diy guy would be to seal as many duct joints as possible. "Duct sealer" and/or "foil duct tape" will possibly make a bigger difference then playing with filters. (Do not use "duck" tape)
If all of the ducting is hidden or enclosed then this will not be viable. But..... If it is accessible, then wow you will see a difference.
FYI
If ducting was improperly sized(undersized or poor layout) you may not see an improvement regardless of what you do to cheat and improve unless ducting is resized/replaced.
Bro that's the whole video. Register restriction and filter Merv
I’d bet 80% have low air flow.
You may be right