DIY Solar Heater Wall (NO SOLAR PANELS needed!) 

As a subcontractor working with water you may want to either extend the roofline or add a gutter above this solar wall. Keeping water off of this setup would likely extend its useful lifespan significantly in addition to keeping it cleaner which will aid in effectiveness. Adding light colored gravel or leftover metal roofing/siding material at the base on the ground would increase heat through reflectivity and lessen splashback and dirt buildup. Very nice job guys!

This system you built is called the Trombe Wall, after engineer Félix Trombe who designed it in 1956. But he has installed a thicker heat absorbing material (stone wall), behind the glass so that the heat is stored and slowly released into the building for hours. You can use it for heating and cooling the house.

We built these in Indiana about 40 years ago. We called them "traum walls". We used cement block walls filled with concrete to hold the heat. Worked fantastic

I was showing my husband your video because he had the same idea for one of our future shops. Anyways he recommended putting air filters on your bottom vents so the shop dust doesn't get in your air space making the sun not work as efficiently.

I experienced a house about 40 years ago that was designed by an architect, a student of Frank Loyd Wright. Built around 1969, one feature was a sunken living room with black slate floors, 12ft tall window sections in a south facing wall, louvered screened vertical panels with doors that you open at dusk to let in the cool air ... close in the morning to keep out the summer heat. Soffit overhang was designed to help limit summer sun exposure. House was built on the bank of the towpath for the Miami Erie canal adjacent to the Maumee river. There were trees in front that provided shade in the summer, leaves drop off in the fall allowing more sun exposure when at lower angle. There was a lot of thermal mass in the slate and locally quarried limestone.

In the days before central heating those wealthy enough to build a large house with surrounding land usually built a conservatory onto the house which was basically a hot house made of glass panels. It was used to collect heat and light in the winter months and get rid of heat in the warmer months as many of the panels were opening windows and the glass area could be reduced with shades. Passive systems fell out of favour when new fangled inventions replaced them.

I've seen this concept in mother earth news years ago. One of the things about that design was having 24" roof overhang to shadow the wall as the sun rises with going into summer. That way, you're not heating in the summer. Also, drapping a lite plastic over the top vents will stop air back tracking through the wall at night acting as a one-way valve. I love your take on it. Great job and thanks for showing it off.

Recently used these panels to make a porch roof, they’re great like that. Slightly cooler in the summer, definitely warmer in the winter, and rainproof!

I have access to those panels for free at my work, though sporadic supply. I used these for the roof on my chicken house and run. I also made a small 4' square greenhouse to put over my Agave every winter. I brought it back from San Diego to Washington, and it has been fine for 7 years! I put a small light fixture with 100 watt light bulb with a terracotta pot over the light fixture, which heats up and keeps the greenhouse warm.

It’s not often I subscribe on a first viewing, it takes me usually a handful of episodes, not here ,I instantly felt comfortable with how you present yourselves, and your humble attitudes, not found often on RU-vid anymore. Kudos and keep en coming.

On your next one, consider alternating horizontal baffles so the air would have to snake back and forth and picking up more heat. You don’t want to short circuit. Great job though!

Kind of like the brick columns in castles combined with the open seller windows on opposite wall, which act as an elevator to exit older warmer air our the windows on all the other floors. On better buildings they built 2 of these brick columns on opposite sides of house. They controlled an entire castle using this system. The Egyptian Pharaohs had this skill down perfectly and could rush air into their temples and pyramids using colder night time desert cool air intake. I'm in AZ, still using this method I learned from my parents before the AC was invented. Since the 1800/1900, the attic fan opening venting exhaust air out the roof, combined with down stairs intake windows, is based on this early castle principle.

Wow, first time seeing a solar wall on a big scale like this. And it looks so good. Best free heat idea out there in the homestead solar community. The common name of these plastic panels are polycarbonate panels, comes in double and triple layer. Congrats on figuring out that light sensor relay thing, I get it. Small detail of improvement, a little bead of silicone in the hole before screwing the panels, so you don't get water in thru the screws. I know the panel drains, but it'll keep moisture from rotting out lumber long term. Good job at keeping the electronics fairly low tech and inexpensive.

Just happened across your video. I like this idea, I'm going to do this but I am going to include some solar hot water heaters so that I have some dual use. I can use the hot water but it also will have added thermal mass to the wall - hopefully allowing it to heat the room past sundown. Thank you for sharing. Well thought out and great explanation of the process. I'm subscribing.

I have a similar system (smaller) on my Home this is our second winter, and on a sunny day here in SD, ours can push between 180 and 200f into our house and paid for itself the first winter. The one thing I had to retrofit onto ours was covers for the summer months, so once the outside air reaches nighttime temperature on average in the 40s and the day temperature in the 60s+, then our heater hits around 350f and can start to damage the unit. I cover our 4x8' unit with Exterior UVC alumna back foam board screwed onto the frame. I would advise you to come up with something similar as your system will be producing a lot of heat once the sun lifts above those trees. I, like your vent fans, took me forever to find something that works for our system. Informative video and a great project!

It's called a Trombe wall. They've been in use for about 50 years now. The ideal design would have a mass wall behind it; about 6-10 inches of masonry to modulate the heat cycle in the system.

Some types of these thermal walls have an exterior top vent that can be opened in the summer so that the thermal chimney effect can be used to draw warm air out of the building with cool make-up air coming from the cooler northern exposure (optionally passing through buried piping). On the other hand, just removing the solar heat load from that wall with summer-time shade might be better. If you do move the powered vent to the bottom, as others have suggested already, you could potentially use the powered fans during summer to draw cool night air into the building. I just found your channel, so not sure yet what other projects you've got going on, but during the summer when you don't need the heat in the shop, with a little modification to add piping to some of the wall it could probably double as a solar hot water source. Finally, if you like passive systems, check out wax motors! They are often used on greenhouses to operate vent dampers. Basically its a sealed container of wax with a piston. As the wax heats up it expands and operates the piston. Very handy for physical control of temperature-responsive systems. Combine with a bi-stable flexure mechanism to make dampers that snap open and closed at various target temperatures.

I love hearing ya'll troubled shooting and explaining your process. Ya'll are such an awesome couple ❤😺

A simple way to turn the fan on when the sun shines is to use a 12 vdc pv panel and 12 vdc computer muffin fans. Direct connect the pv to the fan. When sun shines fan is on, fan shuts off with no sun.

@thehomesteadingrd I would recommend trying it in *reverse*. The hot air you are collecting is blown...where it will stay, at the top of the room. Instead Reverse the flow of the air to pull the ceiling air, into the cavity that is warming, and let it push the warmed air out of the bottom vent. The warmed air will significantly improve how warm it feels by better mixing and putting heat where you are. Also, heat transfers fastest between things that are the most dissimilar in heat. So, since the air, floor, and items in the shop lowest are the coldest and will be improved more this way. Try it.

No joke I was just thinking about how to do this in our little living space the other day. This is a sweet, and very simple design for this.

This is a really good idea and your work ethic is great. Can't wait to see what you guys do next. ❤

The sweetest clever couple .. Beautiful calm energy & wonderful detailed info !! Cheers .. I am most impressed by the respect you share for each other !

If you want to tweek it even further add an insulating blanket that rolls down. An insulated wall that tips down like a drawbridge also works and has the advantage of being a reflector on the backside, providing you make it reflective lol.

Great job!!! If you change the bottom vents tape a house wrap flap on the inside. this will seal the vents to prevent reverse flow of cold air at night. You can also add an overhang of about 2' to provide summer shading, there are calculators to define these for your Latitude.

Looks like a typical Trombe Wall, I've seen them being used in Northern New Mexico for the last 40 years. It's a great system.

Great job and video! Not sure if anyone else commented on maybe putting some filters on your bottom vents to keep your system clean of dust build up inside your wall. Just a random thought.

Very cool 👍👏❤️ I would like to recommend that for future videos film as the process goes on to teach what you are doing. You can either show us a bunch of short 10 minute videos as the process goes on or one longer video ( preferred by me 😂) to show us and teach us. Love you guys and will always support you!!

Very cool idea! Love how you used the variable fans with the wall. Thanks for the content!

Close all your vents at night, or you will let in cold air at night. Awesome job!

I came up with this type of idea a long time ago. My system is still priority to do commercially one day. But, I'm looking at going into prepper low tech solutions, with a number of designs for different things. However, I love seeing other people work it out. There is a Russian guy who does a lot of DIY geothermal solutions.

Great job! The space between the walls will need direct venting outside for the summer as the temperature of it might get very high and ruin the clear plastic sheets in just a very few years.

You guys did an awesome job, I love it.

Very cool and smart! Thanks for sharing! Just a side note, if you haven’t already done it, I highly recommend a blower door test! They’re the best way to find any areas where air can leak!

What beautiful children may God bless your family

Thank you so much. I had forgotten about this technique. I'm designing my own studio and will incorporate something like it. Well done!

If you use a light sensor that turns things on when it gets dark, hook it to a relay using the nc contact, When it gets dark the sensor will turn on power and open the nc contact shutting off power to the fans. I do love your use of passive solar heating.

Man glad to see someone do this been thinking about this for years

I built my 20ft wheelhouse using a similar concept. Not done yet but my test panel created 140 degrees in a 41 1/2 x 80 void.

Thanks for making this vid. It’s exactly what I’d been wanting to do in my shop in MN for years!

I usually don't subscribe on a first watch, however your professional presentation and eager attempt to try this was intriguing. Thanks for sharing and keep them coming. Cheers to you both.

Maybe a simple flap at the outside bottom vents to act as a valve, so that cold air does not fall back into the shop would be worth trying? And a simple filter as others mentioned

Great concept 💡 👌 👍 Look forward to a follow up!!

Very clever, well thought out and adapted to your climate. The fact you know your climate zone says a lot about your attention to detail.

I built a solar wall small scale... 4'x8'. @8am 0 degrees F I was getting with morning sun 132f... Clouds would really cool off the wall as they passed so i used metal inside to absorb the heat and work as clouds passed.... Then I found the best trick to heat the air fast besides using metal painted black.... Was metal screen ...it raised the temperature fast in morning and speed startup time as clouds passed .... I used 12v fan on solar so really efficient....

You have to extend the roofline, because at summer it is necessary to cover up from the sun and protect from water! Dont wait until summer because it generates a lots of heat. Cheers

Great concept, nice to see your application, really useful and cheap principle if you have wall space available like this.

Right off the bat, you guys are awesome.

Thank you, keep working.

I did a similar one, but actually made a greenhouse. For the lumber I used inexpensive cedar fence lumber. It had black painted water barrels for a heat sink. But it was in a warmer southern climate.

Very nice installation. I used to build a similar collector on homes in upstate NY in the early 80s for s company based in Petoskey MI. We would remove the siding, frame the collector with aluminum U channel. Place thermax (covered with an aluminum sheet) inside that frame. We used standoffs with channel between them to create a 2'x2' grid. We run two layers of aluminum screen vertically, and put glass over the grid using butyl tape to seal it. We would run a 6" duct with a squirrel cage blower, activated by a thermostat bulb inside the collector, from the top of the collector to the north side of the house. We used a sheet of plastic inside the return air as a reverse flow damper, which would prevent cold air leaking into the house. One improvement we made along the way was to add a recirculating loop with a transmission cooler as s hear exchanger. Two electric dampers in the 6" line would alternate state, so when the house was satisfied, hear would be directed over the heat exchanger, and circulate domestic hot water through it. That way a) the house wouldn't overheat, and b) you could hear your water solely with the collector in the summer. Cheers!

Great job on the solar collection wall. Back during the beginning of solar heating fad they were very common by DIYers. I’ve seen several on houses over the years and was surprised to see several taken down. Nice to see them making a comeback. The louvres on the air inlets might be useful come summer time.

I've seen a similar System Incorporated into homes during the 70s in Arizona of all places. You might need to have a slight overhang to provide shade to your wall during the peak summer. Overtime you can tune it in.

Long ago, in Wawa, ON, Canada, I built a solar wall-type heating system using corrugated metal roofing, metal stud framing, tempered glass shower doors from the dump after a local motel remodeled, and only 1" fiberglass insulation. I made a chicken wire bin filled with rocks and also insulated to store the heat overnight. Ppl don't realize, the coldest days are also the clearest, and so produce the most heat to make up for it. When it clouds over, it warms up. Do not use foam insulations for environmental as well as off-gassing reasons. What I learned was, can actually use no insulation if make a sealed layer and simply use quiet, low power computer cooling fans to maintain a slight vacuum. No insulation needed at all, just like a thermos coffee bottle. Point is, I never had another heating bill, and the house sold instantly at my asking price, because of this.

I love your sense of humor ... thank you for the laugh

Great idea. Greetings from Poland.🤗

I wonder if putting your vents on a dusk-till-dawn timer will aveviate the improper function of the light sensor? Great build, wonderful commentary, and your explanations are clear and consise. Thank you for sharing!

I have totally had to put a relay on a light sensor before! 😂 I love this idea though! 👍

One problem I have run into is Overheating One time I smelled smoke and a piece of fabric had started to smoulder. One solution would be to build an Awning or an outside Rolled Shade that could be pulled down.

I've been thinking about framing the inside of my connex and insulating it with pex all along the roof, the east end, and the south 40' side and putting a large insulated glycol tank in the connex to store heat in the tank and send it to the cabin at night Edit: basically the same idea, but heating and storing liquid instead of heating the air when the sun is out. I live in Alaska and storing the heat for night time is ideal for me.

R15 is the pannels resistance value or insulation value. The thicker the pannel, the more it can resist the colder Temps transferring to the inside.

Have you considered reversing the air flow? Meaning flip the fan register so when the air gets heated it blows return air into the greenhouse and heated air comes out down by the floor where you need it.

@13:15 firstly got to say I love the videos and I think this is a genius method you guys did. About light sensors: my uncle was doing a project couple years back where he wanted a daytime and a night time sensor. He spent months looking and thinking and his expensive solution failed and he sent it back. He had broken one of those little solar panel driveway lights and he wired The sensor backwards in the flow of current and sure enough the thing turned on when it got light and turned off when it got dark. Don't know if that's helpful or if it would even work with the type of sensor you have. Again, love the videos!

From the look I guess the 15 in "Clearview 15" is probably the thickness of 15 millimeters. Welcome to the metric system, you mastered it

My greenhouse is a geodesic dome using the same plastic panels. It heats fine even in freezing weather.

It's amazing what you can do when you put your mind to it. Great video!

That's pretty interesting. My first thought, without having really though what happens, was that an entirely passive system would be pretty cool. In other words, energy creates heat inside the air space, which naturally drafts air up and out in a constant current, which a ceiling fan could push down and mix into the larger space.

I think that your idea for the heat wall is great, IF you were living in the Arctic where the temperatures rarely get above 2-3 degrees, but what happens in your summer when you need cold air??? Your barn construction will be like an oven.

Good Saturday morning from Forest lake Minnesota!!! Super fantastic episode! Tanya and I can't wait to visit you guys and see it!

Neat design, thanks for sharing. 3 to 4 degrees in the worse time of the year. Will have to check back to see how performs. I've been thinking about doing the same and have my Dads old greenhouse to restore with some more not wood framed sliding glass windows I got for free, like he did. Been thinking a double or triple burn high efficiency thermal mass heater of some sort would be a great improvement as well, outside of course and pipe the heat in. Min fuel consumption and the capabilities of using multi fuels. That coupled with some geothermal tubes and pipes while digging.

Awesome work guys. Gotta love hard working, smart people.

Great job. Re your original idea:Why not drill holes in the studs to allow the warming air to equalize before it enters the room. Its seems with carefully placed crossbracing you wouldnt weaken the walls. I think you just reinvented the Trombe wall

Appreciate hearing of your successes and what you learned to improve. Sharing is caring.

It may be worth putting the fans at the bottom so that the rising warm air inside heats the wall while the wall heats the air from a higher starting temp. The lower fans will introduce heat to the living space instead of needing to fill the roof void before putting heat where you are. Great idea.

My pops went a bought a pair of those electric metal sheers…that Dewalt makes…they work ok but he decided that the grinder and the skill saw with the metal blades work best…hate having to cut metal sheets like those…it’s a huge pain in the rear! But the metal does last so much longer and is a lot more durable then anything else…thought I’d share where I get the metal we use for a fraction of the cost…we went down to the scrapyard and asked if they sold it to the public by chance…$.25/lb and they had stacks of it…in really good shape too…we built a garage/shop that’s a 20’x20’ and only spent a total of $1500 altogether…the mostvexp naive part as the concrete and the screws lol…we had found some galvanized 3” tubing that were 18’ long with the ends pinched and holes in them…so we cut them in half and made the roof trusses out of them and used them to the wall framing….I still have to paint the outside to match my home but I thought it was a hell of a deal considering I’m a single mom living on a very tight budget..and now I can work on my vehicles inside a shop instead of out in this freezing cold…so maybe u could find the same sort of deal for ur future shop…if u have any scrap yards around just go and walk around and see what they’ve got stashed if they sell it back to the public like mine did…I love the solar panel idea too…gonna look into doing something like that for a greenhouse next….thanks for sharing! It looks totally awesome!

Similarities to a “trombe wall” for (semi-)passive heat.

Good thinking/reasoning kids. I've seen variations of this concept but, never done exactly like this.Well done indeed.

Great idea and good job walking us through your installation process. I am positive this is going to help lots of people formulate a plan for their solar walls.

Great video and thanks for breaking it down so well. 😎 I haven't installed one in years but for outside light controls I used to install a programmable switch that you could set the date and latitude on and combined with your reversing relay it would take care of your fan issues. It mounts indoors away from the elements ; a dozen or so years ago I think they were $40 ish dollars Canadian and fit in a standard electrical outlet box.

Very interesting. Ingenious. Only question how does it work in summer when you want coolness?

We are going with a modified Earthship style greenhouse - great video on the material!! Thank you both!!

I have built a green house attached on the south side of my house and heats up the whole side. 20 degrees outside and inside 50 degrees. Yesterday it was 10 degrees and it was 40 degrees inside. I used polycarbonate roofing panels.

Several years ago I ran across a similar system and was wondering if I could do that on a larger scale to heat a building- you have proven it with this video. I also want to passively heat a shop in winter (haven't built the shop yet) but since I am in zone 4, this might be exactly what I will do. Thanks!

a really inventive way to use what is around you and minnesota is cold around winter solstice. iliked the simplicity of it.

I made an 4'x8' solar box to hang on an outside wall. The horizontally divided airspace allowed heat build-up and was passive flow. Only ran one winter (moved), but it had nice warm output. Using the Durarock as a heat "bank" is a great Idea!

Good information & update on costz. We call them "trome wall".

(1) How much of a gap was made between the green house panel and the black painted wall? 4", 3", 2" ? (2) Are those fans powerful enough or could you get more hot air with a faster circulation? (3) Wouldn't you want your hot air to come out at the ground level so the heat rises?

Great job! If you wish, in the next project you can try to paint black not the wall, but the slats of the blinds, glued with reflective foil on the back side. The blinds can be controlled from a thermal actuator (for example, a piston type).

Awesome job. I did this about 24 years ago. Works really good.

Great job! I hope it works out wonderfully. Thanks for sharing.

I have studied Passive solar heating and understand every effect and benefit after operating the two Homes with south facing walls that just collected and released so much heat, to pay my heating would be costs 6 months out of each year. The system even heats a percentage on cloudy days with bright sun barely covered laying in more free solar Heat. My 4 giant maples reducing summer heat saves on ac by reducing energy needed to cool a hotter house.

I just Love this. Your husband is very smart. This video is now saved and shared. .Thank you for sharing ❤

I can tell you guys are good people

KLT. Good job, both coming up with the idea, doing the work, and explaining what you did. PS I am 72 and have been around alternative methods since the 60s. There was a guy named Tomlinson, I think, back in the 70s who used similar methods in home construction. Just an FYI. Thanks

Wow, this is amazing. So appreciate you sharing your idea. New Subscriber so I can follow you now. You two ROCK!

I love it. I am currently gathering info for off-grid or low energy heating systems for my new acreage in Alberta Canada and I think this is genius. I will be building a pole barn (barndominium) and have received some quotes from steel building manufacturers here in Canada but the cost is nuts. I am now looking into just buying all the materials needed and hiring a contractor to construct the building for me - any thoughts/advice? After seeing this video I think I will ask for the drawings to include this system into the south-facing wall during construction - who knows maybe it will save money by not needing as much corrugated steel siding?

Very nice presentation. Thank you.

Hi, because of the way your wall works you might not even need the fans especially if you have a larger hole at the top you can make a thermal draft which will lower the cost again. Anyway nice work and it looks good.

Thanks for the share and take care of yourself.

Great job guys.