Solar Heated Garage Radiant Floor, Update
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- Опубликовано: 27 фев 2018
- Today I took some temperature measurements of incoming water from the solar collectors, and the radiant floor. The garage/shop is warm today (61°F) but it hasn't been this warm all winter. I've been able to keep the garage above freezing this year using only the solar. However, sometimes it dropped down to 40°F during the coldest spells. On average the shop air temperature was 50-55.
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Thanks for sharing, just finish watching all 16 vids, and thanks for the update. ive always wonder how to do similar things in the pass.
Thanks for sharing your work, your pros/cons, and what you'd do differently. thanks!
Your welcome, thanks for watching.
With that high delta you might want to consider upping the flow rate through the floor to get more heat to the slab.
Yep, get every bit of heat you can into that slab while you're generating heat as long as it's not so hot that it's running you out. It's the slab that you want storing the thermal mass in this case, not the tank unless the slabs hotter than you can handle.
Great job !
awsome work
Great job
Have solar heating at home, and i have a 3000l tank that are heated by big coil in the bottom of one of our tanks and it works great.
I will be doing the same thing as you fella. Nothing like the sun for heat !!!!!!!!
Superb setup David, props.
Thanks Vincent.
@@DavidPozEnergy iam starting to follow you from 🇨🇦 #YSW how could I DIY the Soloar Panels would I have to build the from scratch the Soloar Panels the reason I ask this question is i would care to build a Greenhouse and to use the water to warm up the Hoop Greenhouse and use the water for warming up the Soil and the Hoop Greenhouse Thank you kindly 🙏 Domenico Monteleone ❤️ what would happen if you added more Soloar Panels to ypur own Garage my message to you
I wonder how much different the results would be if, instead of the costly panels big heat-exchange tanks, you ran a grid of black-painted piping across the roof and shunted that directly into the radiant pipes.
A great project and a very good implementation! The radiant heat is equalizing with the ambient air temp in the garage, resulting in a lower than expected air temp.
An inexpensive and fun project to bump up the air temp during the daytime, would be to mount a couple more passive solar collectors (aluminum downspout designs work well) on the roof and ventilate the garage with the heated air.
I'm going to watch all of your videos
Thanks. Be warned, the early ones are terrible from an editing perspective. LOL
might want to consider a hard top on your tank, safety concerns for little people climbing on top. thanks for all your great videos. i have radiant flooring oxygen barrier pex installed in some curing concrete as i type this :)
Great!
Setting 3 or 4 (constant pressure 1 or 2) is recommended for a Grundfos pump running radiant floor heating. Try it out!
Many years ago I worked for a brilliant engineer who heated his whole high ceiling, metal roof factory via underfloor heating. Air temp was never high but his female workers never moaned about being cold as their feet were always warm even with snow outside. I swear by underfloor heating now. Hot water is best but electric is super easy to lay by comparison and I have it in our kitchen and dining room and it works brilliantly with zero wasted wall space from panel radiators and a MUCH better feel to the room warmth at a far lower air temp than with panel rads.
If your solar panels are free then use them. Otherwise the BEST panels are cryo panels which do not require solar (but collect MASSIVE amounts of energy if there is sunshine) otherwise they get their heat by trying to "freeze" the outdoors to -40C which will never happen except in the very coldest of cold Northern Canadian nights. So they are always pumping heat and as soon as they get sun the heat output just soars. Not cheap, but bloody fantastic.
You can make your warmer work better efficiency by connecting the elements in parallel. Like: in series water heats up in the first element, then it goes to the second element, and MAYBE heats a little more. But after that, it is already warm water and does not heat any more.
If you connect them in parallel, every element gets cold water, and every element makes cold water warmer.
This is very cheap way to even double the efficiency of your warming elements.
I must agree. We have three evacuated tube panels on our off-grid home, plumbed in parallel. If you plumb in series then each panel receives ever warmer fluid (glycol, in my case) and that reduces its efficiency.
So long as the output from a single panel is always hot enough for heating purposes.
You could use a 50 foot x 3/4 in soft copper. If you did make your own heat exchanger coil use 1/2 copper tubing for legs use caps on bottom.i did a commercial system in Lawrence we had a rubber 450 gallon tank with 3 coils.i used sonna tubes to wrap them.then braze the small copper to the outside it looks great and works excellent. Heat exchanger whether flat plate of shell and tube are not ideal.if you would have got a indirect tank with an electric backup you wouldn't have to do anything just run your solar fluid and fill that puppy up. You could easily turn it in to a open loop drainage system. You could use a 40 gallon indirect for your storage room and use the coil inside to run a fan connector or a piece of base board and a fan. Enjoy glad to see your vid.
You could put that water heater tank on a timer.
we have to do one!
Nice job.... New to solar. I am planning to do something like you done when I build my garage. Recently I been attending a solar club in my home town. We can get solar panels at cost. "Wheels are turning." Thanks for the video. Cheers
That's cool. Are you in Massachusetts?
Hello my friend. No, I am in New Mexico....actually, I am a contractor working in Kabul. I'll be home mid Sept. I have a small solar plan for my log cabin. This log cabin is a practice build. Freaking about $28 sq ft so far. lol Keep your video coming. Cheers
My experiance with Grumman Sunstream collectors that used glycol heat transfer fluid under 8lb of pressure and homemade water only colkectors is the commercial collectors transfered 30% more heat. The glycol under pressure is significantly mo getter! You are leaving significant heat within the collectors which can be measured by sampling the plate temp and comparing to the water temp as it exits the collector.
I vaguely recall your video of insulating the garage. ...a lot of insulation. In this video and in the comments you detail how many BTUs you collect to heat the garage.
Where do you lose the heat? There is a gizmo of some sort ...a infrared "gun"... that shows hot spots. I'd be very interested in seeing the results/illustration of where the heat leaves the garage.
Great work you're doing, btw.
My biggest heat loss is the doors. Second to that, I'm assuming is when I bring in the cold car covered in snow. Then I'm using up the stored heat to warm the 3000 pounds of steel and melt the snow.
With the right amount of reflected light on those panels, this would work great. It wouldn't take much. Maybe 3 to 1.
what reflector would you use and how would you mount it? And what do you mean by three to one? Can you elaborate? Thanks! Sounds interesting...I mean one of those collectors could receive from a really big, Mylar trough parabola so big, it might max out the plate receiver's capacity (and best to check for styro backing to replace with rock wool lol )
best heat exchanger is radiator :D
looks pretty warm outside there, lol
Looks great! What is your design load? how many sqft? what are your R-Values? I went with a 3/4 ton mini split for heating my 960sqft house with a design load of only 8000BTU/h. Averaging R-50 for all surfaces. My house is a second story addition over garage so I couldn't use tons of thermal mass like you without a large complicated water tank, and I was going for simple.
Hi Joe, I'll answer your questions to the best of my ability, but forgive me I don't have all the numbers.
The garage is about 1,200 square feet, 28x44 with 12' ceiling. R-100 blown cellulose ceiling, R-56 foam under the slab, and R-20 walls. I have some construction videos of the garage up on my channel. Also, check out this video on how I heat my house: ruclips.net/video/8PaT7dcOJfM/видео.html
You should check solar air collectrs.
So you could also use photo voltaic panels & direct drive an electric immersion tank to save on the complicated plumbing
Yes, you are right. I am actually working on setting up that experiment so I can gather some data.
The other two ways to heat that I’ve looked into are, hydronic’s and Triple solar’s PVT-they’re from Europe. Both of those methods are extremely expensive!
Great Set Up #777Slots
David, If you want a warmer garage, then for about 200 dollars you can install a 24v dc water heater element, They run around 25 dollars and a 100 watt panel for 100 bucks, some wiring and swapping out one of those ac heater elements and you should be good to go.. another way is a dump load ( water heater element )from a small wind turbine.
Solar thermal panels are more efficient than solar PV panels. If goal is efficiency, PV panel is not the way to go. If goal is cost, however...
Goal is both. Check out this video to see how I got the panels cheap: ruclips.net/video/9Nd9k1rQPW8/видео.html
They may be more efficient than solar, If you need extra boost during the winter you will need something else, solar and wind can help with that. There are more ways as well to help with heating such as a coal or wood boiler that you can use for helping the heating system also.
Think about it: a 100W panel can never produce more than 100W. A 100W heating element will produce so little heat you will never even feel it in a space the size of a garage.
What you need is a water to water geothermal style heat pump. That is the only way you are going to extract all usable heat from your solar heated water and get your 60 degree temperature in your garage due to much greater efficiency. It would also possibly need some solar electricity producing panels and some batteries as a storage and power buffering for that electric power needed for the heat pump. It would be worth it for the gain in efficiency you would get.
There is this solar water heaters in mexico that most of people use is no power involved at all and a single unet can support a 10 person home for kitchen and bathroom
Insulate everything is usually most cost effective
One thing that would raise the solar efficiency, and heat output of this would be to use a vacuum tube collector. These are about 80% efficient, and they are not too expensive.
Hi Neil, I agree. I went with flat plate collectors because I picked them up for free on craigslist.
Free is good! You're doing a great job, by the way. My brother and I have been completely rebuilding the roof on my house, and we got a 10.1kW solar PV system installed about 6+ weeks ago. I am hoping to add a battery storage system at some point soon.
My plan is to have R72 in the 2x12 rafters - using blown in WOOL insulation. Pretty amazing, really.
That's great! If you haven't seen it I have some videos of insulating my house and garage. Here is a link to one of them, but there are several older ones. ruclips.net/video/k8g9Q___CJ0/видео.html
I have herd of solar panels stagnating and overheating in the summertime. How do you overcome this? Great video, thanks for sharing your experience.
Thanks for watching. You are right to be concerned with overheating in summer as a potential issue. This problem can sometimes happen with glycol based systems. These are sometimes called "closed loop" systems and have glycol mixed in the fluid to protect against turning to ice. However, if they don't have a "dump load" and/or loose power, they can boil and kill themselves. The system you see on my garage is called a "drain back" or sometimes called "open loop". I have no glycol. Instead, my transfer fluid is just regular water strait out of the tap. If there is any failure then the water just drains back to the tank. This is also the freeze-protection. When the water drains to the tank it leaves the panels empty (filled with air in the pipes).
Hey, nice system! I have an idea - could you immerse that returning pipe and put normally-open solenoid valve above water level with T-shaped pipe connector (solenoid is powered when pump is on)? That way when pump is stopped and solenoid loses power, then aircap is openened and panels can drainback. When pump is running and valve is closed, then you dont hear that water-sound (depends if it is issue to you or not) and pump can probably work more efficiently because it works as closed system (that needs to verified)
What do you think? Does it improve system?
Your idea sounds like it could work. I don't know for sure, never heard of someone doing it. I like the drainback because any failure of anything will result in the water draining back to the tank and the system being protected from freezing. Adding a solenoid air vent sounds like one more thing that could go wrong. However, I could see doing it if the water sound is a bother to someone.
Probably easier and safest option is to immerse pipe and drill small hole (3-5mm) to pipe above waterline - that way it still can drain...takes just little more time. And you get rid of flowing water sound (at least most of it). John Canivan suggested something like that in some video.
Or just direct water to tank wall at shallow angle, so it flows on wall and does not fall
Hey Dave, I have also just picked up 3 of these panels myself and watched your videos to gather some information about how they work. They all are approx. 4x8 and came with a roof rack that the last owner made to attach to his roof. I’m looking to heat a 12x24x52 above ground swimming pool during the summer months on Long Island. The pool is chlorine not salt and I feel that this could really be a great DIY project to provide a better swimming temperature. I’m unfamiliar with how efficient these panels can be and curious to know if I need that many? Any feedback would be great! Thanks for your help and the great videos!
Hi. I think you can simplify your system because you want to use it during the summer, I'm guessing mainly during the day. There are diy solar pool heaters that are simpler. They use a small solar powered pump to circulate the pool water through a passive glass toped box which heats the pool. The boxes are inexpensive and a easy diy.
just a litlle tip lots of people fail when trying to increase the size of there heating equippment...I always say insulate +insulate and i bet you i will be installing you a smaller unit what ever the unit you want i can instal it...your garage door only R7 if insulated so if u insulat it you will see imediate change and lest wear and tear of your system trying to compensate for all that heat loss...just saying David...:)
Hi beez, You mentioned you are in HVAC. It is rare to find one that pushes insulation. Thanks for doing right by your customers.
I have a great respect for my customers and i never never lie to them so at night i can sleep well...and my customer base is huge and all by referral + my studdies included GENERAL CONTRACTING 2 years full time at high cost so i no quiet a bit on building stuff or codes thick has the bible...loll so i can see all aspect of the problem often i refuse to enhance there system and refer them to an insulation Co.or of there choice...sometimes and more then often there surprized but i aint in the BIZ to cheat or for the Bad money im in it because I love my job...:)
Be neat to design an insulated water tower that had a solar vacuum tube water heater with copper heat exchange coils coming up from the bottom of the tank with super heated gallium being circulated through the heat exchange coils with the heated water then being circulated through two underground insulated cisterns that kept the water hot were you could add in thermal electric generators has well to the system. Its always best to have a few heating and cooling electrical power generation redundant systems just in case the main systems fail. 😊
It would be a neat experiment but Peltier (TEG) are horribly inefficient. It would cost less to buy photovoltaic panels (unless everything was free). Now if the heat were coming from another source besides the sun, like a hot spring Peltiers would be very interesting.
Would your system warm the garage more if you doubled the collectir panals? Or is it more complicated than that?
Hi Steven, More collector area would heat the garage more. That is not more complicated. If you do want to look at it in more depth, then here are other things to consider: 1. the west side of my roof is in shade more hours of the day, so if I added more collectors over there I would put them on a separate pump and controller. 2. In DEC and JAN the wall has a lot of shade from neighbors trees. You don't see that in this video because it was filmed on the last day of FEB.
I didn't see how your floor was built. Yes its concrete but how did you insulated the concrete from the ground. I have done a lot of in floor heat using boilers in Canada and have always argued with engineers on how to do it. Like to know your thoughts and ideas
Hi George, I hope we are on the same page. I like insulation and think the warm concrete floor should be separated from the earth. I have a video on making the floor, and the insulation. Here it is: ruclips.net/video/s9Pmt7XG_2c/видео.html
How about making a window to let the sunlight in?
Maybe a bigger storage tank. Sve uup BTUs when it's sunny.
heya nice wen you can work in a heated garage
Hi Dave. Looks like a fun and worthwhile project but what are you doing to control legionella bacteria in that warm water in the open tank?
I did put a little bleach in there, but the open tank is not exactly wide open. It still has a sealed rubber lid, so that I don't have to constantly replace water that evaporates. Thanks for watching.
Now, is there a way to send cool water through the floor to cool the place off during the summer?
It'd be really great to have some kind of hybrid system.
Hi Nick,
Cold radiant floors don't work in my climate because we have too much humidity. The floor will be covered in condensation. They are OK in the desert. Thanks for watching.
DavidPoz Ahh yes, that makes sense!!
Dig a really deep hole. Bury coils of pipe and cover up and pump. Not sure how deep or how big.
Could you explain the hot water heater for me? It appears to be inline with what's going through the floor so that if it were to get really cold you said you could turn on the breaker. But you also said that the pump runs at 2/gallons a minute and that water flows through the water heater. If so, do the elements just heat the water as best as possible because there's a constant flow? Or does it eventually just get the whole water system (in the floor and heater) up to whatever temp you've set it? I'm asking because I have four solar thermal panels and I'm trying to design a system where I can maybe use the panels in connection with a water heater to maintain a constant water temp at 180 degrees to feed a swimming pool heat exchanger to heat up my pool.
Not sure if I missed the question in all the comments or not. But after you did your water heating test and found that the solar electric panel and heating element was more efficient than the solar thermal panel for heating water did you change out the elements in that water heater and start heating it off a couple panels to assist your system? I have thought about trying that with my hybrid hot water heater so it would only need to run the compressor in the winter?
inside my house I still have a 250 gallon tank with 3 solar thermal panels. It pre-heats the water. Then I have a 19 gallon electric "booster" tank.
It's about 30F-40F most of the time in the winter here in Southern Oregon. Would a similar system in my next garage keep it around 65F you think?
Thanks for watching the video. There are a lot of variables to answer that question in detail, but here are some things I would consider: Sun-hrs in the winter for your location? Where I live I receive about 4 good production hours in DEC. and JAN. per sunny day. The panels on my garage wall are partially shaded, and my roof is a pretty shallow pitch (less than ideal). But let’s just say I receive 10,000 BTU's per panel per sunny day. (I get more from my house panels). Then I can work with 70,000 BTU's per sunny day. Will that keep your garage 30° warmer than ambient air temp? It depends on your buildings insulation, air-tightness, and size. So... maybe?
Is your slab going to be well insulated? If not, you are wasting your time. Do not ever be fooled by the notion that 'heat rises'. It does not! Heat moves from warm to cool and does not care if the cool direction is down.
You should build a better lid for your water tank
I have started to research solar heating for my garage it is plumbed for in floor but no heat sources.
I am wondering why you are using a heat exchanger and not just pumping it directly into your floor?
The first year I built the garage I had no solar thermal, just the radiant floor with the electric water heater. I added the solar thermal as a retrofit. In order to add to the existing system I used a heat exchanger. If you are not doing a retrofit, then go ahead and pump the same water from the floor up through the panels. If you make a video about, please send me the link as I'd love to see it. Thanks for watching.
If you live in a cold climate never use water. Use non-toxic propylene glycol. You can pump it directly through the floor circuits. No need for a heat exchanger. If you do use water and it ever freezes you will crack the concrete; I saw it happen once. Not pretty!
Thanks for the vid, bud! I'm looking for a way to passively solar thermal heat my off grid garage. In your opinion, if you routed the heated water/antifreeze through a series of radiators, as opposed to a radiant floor, do you think that would work to keep it above freezing? My floor is an existing concrete slab so radiant flooring is not really an option in my situation.
Radiators don't work as well as the floor. I'll try to explain a little more:
Typically, a radiant floor will have a water temperature set to 90°F, but radiators often have a set temperature of 160°F. This is because the radiator has to heat the air around the radiator enough to cause convection (air movement). If the outside air temperature is 20°F, and you try to heat to 90, that's a 70 delta, which solar hydronic can do. But, solar hydronic has a very hard time handling a 140 delta.
The solution, if you want to do it anyways, is to increase the size of the radiator or add a fan to have active convection.
@@DavidPozEnergyHey, thanks for the reply. That's good news for me because I have plenty of solar electricity I can draw from to power a fan on a radiator. I don't need it to be warm per se, just not below freezing so I can leave things in there that would be damaged or destroyed by sub freezing temps. It would save me a lot of effort moving all these items to a warmer space during winter. I'll have to make time to build one of these setups. Thanks again
Is your slab insulated and what is your walls and ceiling insulation level, add some more insulation.
Yes, my slab is super insulated. Here is the video on making the slab: ruclips.net/video/s9Pmt7XG_2c/видео.html
@davidPoz I am wondering why you use the heat exchangers and dont do a direct cycle of the water for the garage floor? I dont know a lot about thermal solar, it makes pretty obvious sense why you wouldnt do that with drinking water but for trying to heat your floor, why do you need to separate the water? i would assume it would be higher effeciency? Love your channel, i found it about 3 weeks ago and watched every single video (except the ones without a title)
Hi mark rossi, This system is called a drain-back. At night the water drains out of the panels and back down to the tank for freeze protection. If I filled everything without a drain-back, then I would need a lot of anti-freeze. And I would need some kind of valve to prevent thermal syphoning (which would cool the floor at night). There is probably a way to do it, but I just did it this way. Thanks for watching.
@@DavidPozEnergy Thanks for replying David, now that you explain it, it makes sense. I forgot to ask you another thing I keep wondering, what are the solar panel looking things on your house roof? Unless I missed a video, you never mentioned what it is and when you did the solar panels on the custom a-frames in front of your house it sounded like they were the only solar panels you had. I did notice you do your videos out of order a bit though, I was watching them from oldest to newest and was so confused LOL! Are they not solar panels and do you have a video that discusses them?
Also, how do you deal with permits/inspections for all the work you do? I would love to do some of the projects you have done but dealing with plans, permits and inspections keeps me away from it.
Keep up the great work, I was shocked your channel only has 26k subs, I am confident your channel is going to explode in size very soon. Your videos are informative, well edited, and the perfect length to get the info across. Your channel is the first time I watched an entire channels video catalog after finding it!
Hi Mark, I have some solar panels on the house. They are PV, and grid-tied only. I paid someone else to install them when I built the house, and it was rolled in as part of the mortgage. Since I didn't do any of the work I never filmed any of it.
The solar panels in the front yard (on A-frames) go directly into the crawlspace as a heater. I have a video on that here: ruclips.net/video/jFoxIit8NYA/видео.html
I purposefully don't discuss any of the permitting process because it is so different everywhere you go.
Thanks for watching
Couldn't you have some sort of window on the roof that lets light enter and strike a very energy-absorbent panel?
Sure, you can go the traditional passive solar route. I like active solar because I can have a more insulated and air-tight shell. If I had a big skylight I'd have to give up the insulation.
@@DavidPozEnergy I think I would go for something like this. I wouldn't really want to insulate the floor. Plus, when you think about it, there are going to be a lot of instances where that floor insulation comes to bite you. For example, when it's freezing cold you could benefit from free geothermal but with your current system it's insulated away. ruclips.net/video/N6QOZGgbj-g/видео.html
So what does the pump cost to run? How many watts is it & how many hours/day does it run?
I just checked for you. 125 watts total, that is two pumps and one controller. One pump is for the solar and one for the radiant floor. It will run 4 to 4.5 hours per day when sunny, and won't run at all when cloudy. The whole system will keep the garage above freezing all winter on it's own, but admittedly, I would like to tune it for better performance.
Thanks 4 video. Quick question:
Did you consider just having solar electric going straight to a dry system? How qould that compare? Then there's no pumps no water etc much simpler and cheaper?
Ps. For your international audience always add in the velocity celcius temperature equivalent. Outside of USA, we have no idea what this strange Fahrenheit scale means!!!
It's been awhile, but I think I got those hydronic panels for free, or very cheap. This made it worth while to make a hydronic system. However, if you are comparing retail pricing, then I'd have built a solar electric (PV) system.
I bought 7 panels for 200$ and plan to pump the water thru some type of heat exchanger in furnace or try some old cast iron radiators, anyway why cant you do away with copper heat exchangers and just have a small holding tank and just pump that water thru radiator , flooring, etc.?
You could do away with the extra layer of heat exchangers if you design the system from the get-go. For me I added the solar after the fact to the existing radiant floor system. So I wanted to keep the existing radiant floor system as intact as possible. The existing radiant floor system is a sealed system under pressure. The solar hot water system is atmospherically vented. That's why I need the heat exchanger.
The delta between your panel temp and floor/air temp is very high... You also have a lot of heat returning to the panels... I bet you would fair better pulling heat off your panels by running a water to air exchanger. A couple large truck radiators and a couple of electric fans would be able to put a lot more heat into that garage then radiant flooring simply because if the system has been off all night then your solar heater spends most of the time warming the garage floor up from over night instead of actually heating the garage.
This would be interesting!
You could even install a couple radiators after the floor circuit but before the return to the box to bleed off the heat that the floor didn't absorb into the garage air space.
But air doesn't store heat well. His concrete slab does better.
Water-to-air heat exchanger think about it. Before the hot water goes up to the solar panels it goes through a copper coil air heat exchanger with a fan behind it blowing the hot water air through the fan coil. Thus blowing the extra hot air up before it goes to the panels on the roof.
your baby will be able to design all of your systems .. he has watched you construct all of them .
I certainly hope that by exposing her to these projects, that it will have a positive impact on her creativity and problem solving skills. I don't know if it will or not, I have no evidence one way or another. I just want to do right by her. Thanks for commenting.
Can you build a house like this and still adjust the temperature?
Sure, I'm planning on doing something similar on my next house. I'm using this garage to work out some of the details. Right now I use the concrete slab as the only "thermal battery". However, If I built a larger tank then I could heat the tank directly from the solar, and then pump the water from the tank to the radiant floor based on inside air temperature.
DavidPoz Awesome. Good to know. I am getting very interested in this. Thanks for educating me.
why not just use some insulated acrylic for the garage roof? Guaranteed to be hotter than 40F when there is sun :)
Hi tripzero, Thanks for watching. I did not use glazing on the roof for a few reasons. 1. Overheating in the summer. 2. heat loss though the glazing at night. 3. Climate Control (I have a thermostat that turns the pump on and off.)
Next time could you show the heat gun on the concrete floor too. Thanks. A few solar panels with a techluck.com Mppt for the electric water tank would finish the job and net you a lot more heat still costing no monthly grid bill.
Sorry I didn't think of that for this video. I've taken the floor temperature several times before. The concrete is usually 10° hotter than the air temp. Then overnight and into the next day the concrete and air equalize in temperature.
As for the techluck... I've considered buying it when I got my solar PV panels a few months ago. However, it doesn't come across as totally transparent. I would like to see a review showing how many watts to a heater with and without the device hooked up. How much more does it increase production vs. not using it. In past videos I've showed the production with solar PV directly connected to a heater, and % efficiency. I guess I just need more convincing from the maker that it will pay for itself. Do you have any experience with it?
To be honest I would like to see that review with voltages in and out also. I have not decided which way to go for the same reason as you but it does seem to be the easiest way to use manufactures equipment on electric water heaters unless you already have a battery bank and large inverter then direct from inverter with the solid state relay controlled by the charge controller for battery bank protection, or just direct from solar panels with the solid state relay controlled by a programmable 12-32 volt source. Your videos are awesome and thanks for sharing your hands on knowledge which is always the best. Maybe a air to water garage heater would make up the air temperature deficiency in the garage as heat transfer from floor heating is a slow process but the best heat imho.
Evacuated solar panels yield very high water temperatures in low latitude, sun locations.
Hi Jim, I agree, evacuated tubes are great. I used these because I picked them up for free, here is the video on that: ruclips.net/video/9Nd9k1rQPW8/видео.html
Why can you not put the water from the panels directly into the floor?
You can if the water in the system is mixed with glycol (anti-freeze).
Try a solar vacuum tube water heater retrofited to super heat gallium that is circulated through a copper heat exchange using an electromagnetic pump ounce the gallium has reached a certain temperature with the heat exchange coil being placed in the bottom of an insulated water tank above the resivor of the gallium within the solar vacuum tube water hester so the gallium will drain all out of the coil ounce the system is shut off. Then make a water tank insulated with peralite to keep your water hot over night or have an underground insulated cistern with a pump to circulate heated water through a heated floor system. A organic carbon power cell bank could also be charged up every day by adding thermal electric generators to the super heated gallium. You could place them on feed before the gallium enters the heat exchange coil. Then just alternate carbon power cell banks so you use one carbon power cell bank during the day and then one charges during the day that you then use during the night. You could also incorporate V-twin stirling hot gas engines that operates off the super heated gallium to heat the piston cylinder heads with the the fly wheels either operating pumps to pump super heated gallium or heated water or even operate water pumps for a hydroponic green house. You could even circulate super heated gallium through a copper condensing coil and attach a fan to one of the V-twin fly wheels and draw air through the coil to heat a home or green house. If you really want to go all off grid? Then you could manufacture a V-20 stirling hot gas engine with high heat magnetic bearings on all moving parts and then attach an automatic bicycle transmission to each fly wheel the attach a large rewired drum motor generator with magnetic bearings with a vacuum spark gap to each automatic bicycle transmission and have a state of the art electrical power and heat generation system. Well if you understand everything i have shared? Hit me up and ill explain a cooling electrical power generation system using liquid air and a stirling V-twin or V-6 or V-20 Stirling cold gas engine that can provide air conditioning refrigeration electrical power generation and a way to chill oxygenate and add nitrogen to water being pumped through a hydroponic green house. 😊
If you're so smart please build the system you describe and post your own RUclips video for us all to see.
Hey David, I have about 30 solar thermal systems that I'd like to sell all together. I'm close to Washington state. I'd sell them all for $3000.
Do you have them on craigslist? That is where I found all of mine.
DavidPoz Not yet, I have to figure when I have the time to meet with anyone interested. Right now I'm working about 800 miles away from home.
Good but bit extreme .
Wished I had the experience and cash to do the same... But, why not build several black boxes with aluminum screens to collect hot air. seems it would help your system ++ very cheap and probably the biggest bang for the buck. They are not fancy But I saw a video with a guy below 0 in Canada heating a large chicken coop with no insulation and full of hols the inside temp was about 40F. Now even if they only heat for 2 to 3 hrs I think that would still justify the cost.
There are lots of types of solar air heaters out there. I'm a fan of them. I did it this way for two reasons. First, this requires two holes in my envelop, each 3/4" dia. for the pipe. That's not very big. Air heaters would have required very large openings for passive air movement. Or about 8" dia. duct with a fan to move enough air for this shop. Those are much larger holes with more heat loss in each hole.
Second, I have a radiant floor. The floor needs hot water. It made sense to heat water with solar to directly heat the floor. If I had solar heated air, then I'd still need something for heating the radiant floor.
by the way if you call a tech for your unit make sure he carries an Electronic gauge NOT ordinary manyfolds electronic is lot more efficient and will tell lot faster if theres a Micro leak some were ok take note of that...David
Hi beez, Are you referring to my video on the heat pump, or are you talking about a water leak with the solar thermal collectors?
heat pump David
What will you do during the summer when you don't need it anymore?
I turn it off in the summer. Thanks for watching.
Does it matter if there is water left in the panels?
If water was left in the panels, then yes that could be a problem. However, my system is called a "drain-back". This type is not as common as a glycol based system, but still plenty out there. Basically, every time the pump shuts off (summer, at night) all the water drains back into the tank. This leaves the panels empty. The panels are made of copper, aluminum, glass, and fiberglass insulation. All those things can take hundreds of degrees, so they don't care if they sit out in the sun during summer. I hope that helps, David
Awesome! Thank you for the clarification!
pv panels must be filled with glyco :) FROM HOLLAND
Don't forget to put a jacket on that water heater.
Thanks for watching the video. I didn't think more insulation on the water heater was needed. Why do you recommend one?
I just always recommend them, however since your water is always moving I guess it wouldn't help much.
Why is the tank there - just use a heat exchanger - they are cheap!! I run 10x 1.4Kw solar thermal (14 KW total) configured as 2x 5 series paner running 30% glycol @3.5bar.
This feeds the 300litre Solar domestic hot water via its lower coil and then switched over to the central heating via a plate heat exchanger and in summer supplies the swiming pool via a heat exchanger. We actually had the pool at 31 degrees centigrade this summer. Water comes off panels at between 40 and 100 centigrade and has rougly a 10 degrees differential on the return. This is in the Uk and has been running for 6 years.
Sounds like you have a nice system. I have a tank in the system because I'm using a "drain-back" system. Thanks for watching.
@@DavidPozEnergy That explains the tanks!!
I also ran the sytem initially with just water to flush the system before re-filling with Glycol/water mix and was surprised at how much better water was as a heat exchange medium over glycol, also because the mix is very thick/viscous the flow rates dropped dramatically over the thinner water only.
I considered a drain back sytem but was concerned about the size of the tanks to drain 10 panels and pipework.
Thanks for your reply
That's some good experience on the two fluids. Thanks for sharing.
Can you measure the temp between each thermal panel and if possible measure the approx flow rate of the pump? If we know the watts per square meter(or ft) from the sun in your area then we (the geeks) can find the efficiency of your system. This would help us better understand how to optimize any future designs without having to take a thermodynamics class :)
Hi Josh, I have not measured the flow rate, but according to the manufacture chart, for my head, it is 5 gal/min.
He built a solar system???
Sure, I'm using the sun to heat water, then pumping the hot water through the radiant floor. Thanks for watching.
How long are your loops?
If you are referring to the radiant floor, then I have 4 loops, each is 250 feet using 1/2" ID Uponor PEX with oxygen barrier. Thanks for watching.
Yes, I was referring to the floor. As an ex radiant heat designer as per the Radiant Panel Association I'll say that you have the gold standard in the floor. The delta is a concern. It's too much. A slightly higher flow rate should get that down and spread the heat to the floor more evenly. You might have a little more head than you calculated.
@@DavidPozEnergy On the other hand if you're happy with it just enjoy you're hard work. :)
Thanks. Did you happen to see my video on making the floor? ruclips.net/video/s9Pmt7XG_2c/видео.html
@@DavidPozEnergy I didn't, but I'll check it out. thanks
I have a 90tube domestic hot water system with insulated DIY 200gal softank. In summer one 30 tube panel is all I need. I have to cover the other two. It's a closed-loop system though with glycol added. If I did it again I'd go drainback design. Our side business is long gone but here's the difference closed vs drainback: ruclips.net/video/qOXcbsjUOZw/видео.html , here's a large 16 apartment evac tube solar setup: www.builditsolar.com/Projects/WaterHeating/LargeDB/LargeDrainBack.htm the key to efficient solar heating is a very large well insulated storage tank. In your case, technically, your slab is your "tank" I suppose. But if you add more panels later, your slab may get too hot. That's where temperature regulation becomes an issue. Looking at your return pipe it looks like a drawback setup so that's ideal. I'm working on a large barn design and I'll likely be looking at 2000-5000 gal storage tank. Oh, one more tip, you could add a bit of glycol to your setup to prevent corrosion as there are many dissimilar metals (brass, copper, stainless, etc). I think water pH acidity level also could play a role in copper pipe corrosion. I found in my tank the water was quite acidic. Ended up adding baking soda to bring pH down. But by that time my coils looked like poop.
Good tip. I'll have to check the ph level.
Do you treat the water in the storage tank?
Hi Phil, No, I haven't treated the water in the storage tank. It is just plain old tap water. I've heard distilled water is ideal, but I didn't bother. Because it is a drain-back system there is no need for Glycol. Also, all the parts are copper, brass, or plastic so no rust. I did treat the water in the radiant floor with a rust inhibitor in an effort to (hopefully) keep the tank water heater lasting longer. The tank water heater is a steel tank.
Okay, please don't be offended. But you've got radiant loss ALL OVER that system
Your reservoir is unsealed and uninsulated. So it's a giant hotbox trying to space-heat everything in it's vicinity. INCLUDING THE EXTERIOR WALL OF THE GARAGE!
You've got a wooden box with what is essentially a plastic bag inside it. Remember how poor an insulator wood is? A 4" cross section is something like R2-R3.
Rebuild the box like a cooler.
2" Foam board insulation inside. Spray-foamed together and well caulked/adhesived together. Then, if the rubber liner fails for any reason, you've don't simply begin leaking water all over the garage.
Wooden box in the middle for structural stability
2" Foam board insulation on the outside.
Create a tight-fitting foam "lid" as well. Again, foam inside, maybe plywood in the middle and foam outside. Maybe go for 4" foam inside the top.
ADDITION: Maybe make it a half-lid. Where the back 1/4-1/3 of the box is just a fixed "top" with the pipes going through it (makes those holes easier to seal). Then turn the front of the top into a lift-off lid.
This way the reservoir is completely thermally broken from EVERYTHING.
Next: INSULATE YOUR PIPES! Again, you're getting radiant loss through every bit of PEX, copper and PVC. Sure, the tubes are small, but there's a LOT of linear feet of pipe there.
I also agree that you might see better performance out of the system hooked up in parallel, rather than serial.
Doing just the insulation, I'm willing to bet you can bring your water temps up another 5-10 degrees.
Doing that AND moving to parallel? You could probably get your water temps into the 120 degree range.
Hi Hyperstrike, Thanks for sharing your ideas here, as well as on my other videos. I'm not offended.
I agree with you (and some other commentators) that parallel would be more efficient. I looked into doing it on the garage and this is what I was led to understand: I have two collectors on the wall, and five on the roof. That means the piping to reach the collectors are different, and the piping inside the collectors are different. The differences will lead to different internal friction (the roof will have more and the wall less). So the fluid will choose the path of least resistance. That means all of my fluid will flow through the wall panels and none through the roof. To overcome this I would need two pumps, and two controllers. If I do that I would certainly see an improvement, but I didn't want to sink more money into project. That's rely the bottom line... I'm sacrificing some efficiency to save about $600 (pump, controller, pipes, fittings).
As to the pipe and tank insulation inside my thermal envelope: This solar system is a space heating system only. It will be off all summer long. I don't use it for showers or laundry etc. So if the pipes/tank are un-insulated and loosing heat, what's the problem? They are just loosing heat to the air of the garage instead of the floor. But it is still BTU's into the garage.
I may have missed something, and if I have please let me know. Thanks.
The problem isn't losing heat in the summer. It's they're losing heat in an uncontrolled manner to open air during the winter. You want to push maximum heat into your main radiator (the floor). Right now you're simply warming a corner of the garage right next to a garage door, when the energy could be used in a more even manner to heat the whole garage.
Yes he's losing heat from the tank, but assuming the garage walls are insulated (and he wouldn't achieve the temperatures he is without some) the "lost" heat is just going into the internal space in the garage. i.e. it's not lost, he's still heating the garage.
Isn't 61 degrees deadly for humans ?
Farenheit
one word, glycol. What a complicated mess.
This seems ridiculous. Stop the madness. Put the solar panels on your house. You only need to keep it above freezing because of the unnecessary water pipes you added.
No way this is better than an electric heater running when necessary.