DIY Solar Air Heater! - The Steel Slat “Drip-Edge” Solar Heater! - New Design! 160F 74C in January! 

I built a heater very similar to this one about 20 years ago. It had the air recirculated with simple internal ducting with ports top and bottom. The assembly fit over a double hung window and I could regulate the output by simply opening and closing the windows. This simple solar heater provided more heat than the South side of my home could ever need. No fan, no electricity, just the sun. I frequently had to close the windows because it was too warm. Total cost to build was about fifty dollars.

Your project is much more efficient than some of the others due to the gap at the fan end, this allows all channels to contribute to heating, however maybe if you joined two or three channels in series the amount of heat could be increased as the heated air will be in the channels a little longer. Great job and more than efficient for a home. Well done.

Very nice compact design. Your demo of the building steps is excellent. I have some extra corrugated roofing and a few pine boards I’m going to use along with an old window my friend removed from his house. Mine won’t be as nice-looking as yours, but it’ll pump out free heat to my art studio in the barn. I also like the way you installed the fan and it seems like a cheap investment to add one with a small solar panel. Convection alone will push the heat out, as I learned from a buddy science teacher who made one with his students. They had to disconnect it every day because the classroom got too hot! But I think a fan is probably a worthwhile add-on. Thanks, great job!

You are amazing!!! I like your other solar heater also, but this is going to be great in our RV. Anything solar is number one with me for RVing, and it is easy to store. Keep up the creative flow👍🏾👍🏻👍🏼😊

I thought I'd look for a follow up to your old video and SURE ENOUGH! Keep up the good work.

It's reasons like this that I love RU-vid. At 6:31 in the morning I decided I'm going to research what I'm building next. Better then a college class haha

If you paint the inside (not just sun facing side) with a high emissivity paint (generally any paint is better than bare metal) you'll increase efficiency a tiny bit. I know it seems like the paint that's in the dark shouldn't matter, but it does! It's not dark in infrared

I built up to the box and have the rest. Was about to put in the soda cans and paint. Taking a big right turn to these rails at Home "Despot". Kudos.

I'm going to get this guy some new drill bits for Christmas. ;)

Yes good work man‼️keep up the vids‼️I’m sure you are helping a lot of people 👍🏻😎🔨

Genius! I have 6' X 4'6" tempered glass and am going to build. Thanks for the very detailed video!

We were building these at Mother Earth R&D in the late 60s and early 70s. Didn't have the solar voltaic panels yet. Depended on convection for flow. There was a company in Oklahoma in the late 1800s building them and installing on homes. That's where we got our ideas fir them. Helps to have a house 3' or 4' off the ground to lean collectors under windows for installations for the passive design.

Nicely done. Beats my beer /soda can one that I made about 10 years ago. Less complicated. Thank you

Excellent idea with the drip edging. I do believe the best heat absorber is aluminum window screens. I may use the edging for a smaller unit I want to build for the back window of my truck.

Nice buddy, thanks. I have a 400 square foot cabin in northern BC Canada. I’m going to give this a whirl. Be nice to leave running unattended to keep things from freezing entirely at -20 degrees Celsius. Just have to make pretty steep slope for snow and lose direct facing sunlight. Thanks again.

I have two sliding glass doors to do this with.. very heavy ! Build looks great obvious you could use insulation, and an old double insulated window is a plus. I believe you want the collector sealed in front no air movement and about an inch back from glass. (You will get cold air exchange moving at glass surface especially without double glass). I may use down spouts for my large unit but for a small unit aluminum gutters flatend and reshaped or roll of flashing perhaps bent like yours. great ideas !

Great desing, for the winter I am going to try this one. Also, I was thinking that you should be able to leave some stones in the sun all day and use it to heat during the evening. Soapstone seems ideal, maybe combined with black paint and aluminium.

This would be great for an off grid insulated out house.

Not dissing your idea by any means Brother.. Great build! You want to really bump up the efficiency, duct your inside room air into the bottom of the panel. I had 2 section window units I built that mounted at an angle to the sun into a raised window in my trailer and it thermo-siphoned the inside room air down the back section of the panel and up from bottom thru a slot into front panel section just covered with black plastic and carpet sponge behind it for insulation so back section incoming air wouldn't heat up and colder intake air would drop faster to bottom and was getting continuous 120-130F at a lower CFM of course, back into the room using no power with no fan. If cloud blocked the sun or at night it would just air lock and stop siphoning until surface was heated up again. With 3, 6 foot long, 6" thick double section panels the width of windows only opened 7" for panel front plate to lock into window channel, then window closed down on plate. It kept the rooms comfortable so I was happy. The next year I added 2 small muffin fans like yours to the room fed intake bottom section (on the theory that it's easier to push colder denser air vs suck hot thinner air and less heat on fan motors and plastic blades) but if sun was shaded it blew same temp as inside air with only a few degrees drop and not the cold outside intake air and they were noisy. I heated a 12 x 56 trailer VERY comfey anytime the sun hit the panel. There were a coupe times we had to open a window or door to let some heat out or shut off fans and just let it siphon. I never did get around to mounting fans at the bottom of the panel with a diffuser I think would cut the noise way down, but I was warm and happy so why mess with it! In the spring we just took them out of window and stored in shed. But pushing in 60/70 F room air instead of 20F or less outside air in like yours, across a double metal surface you'd get fantastic efficiency with the fans! ... and wouldn't have to worry about sucking cold outside air into room if panel got shaded and fans were still running. You could do same with yours now without too much modification by adding a manifold box on the bottom where you have your intake holes or cut them into slots across to reduce restriction and load on fan, and ducting in room temp air thru insulated dryer duct into that manifold to feed panel.. Bring output and input air into and from unit from same window insert plate with in and out ducts separated on each side of plate and solar panel mounted below the window and still get light thru window, less 4" for duct plate. We're in the desert now so I haven't played around with panels in years. Low here was 44 last night and 76 today but in New Jersey it was a life saver then! Dang, this turned out to be long winded.... lol

Once again you come up with some great stuff.

I really like the duct/e-box cover connection idea👍

That's awesome good build and very imformative video. Thanks. Will have to make a couple 👍❤

Awesome project. Thanks for making it!

wow...needless 2 say...............u r something special... thank you!

What an eye opener of a video ! Thanks for making and sharing this !!

Awesome build man!!

I made some with metal 2x3 downspout. built my boxes 4x8ft, lined them with 1/2 foam insulation board, left refelective side facing inward. I painted the downspout flat black before putting inside and and sealing plexi glass, and got 250+F. All my testing, I found the longer span you can run the air before leaving the box, the hotter it will get.

This is very interesting. I wonder what could happen here, if you put these drip- edges horizontally, forzing the air to ascend in zig-zag, as the channels/baffles box you have somewhere else.

Fantastic results!!

I used your design and got 174 degrees out of it. I had the air inlet and exit at the top. The air came in and went underneath the part with the drip edge collectors then at the bottom it flipped up to the collectors. The collectors was separated from the bottom cooler air with one half inch foam sheeting. From there it rose to the top and out. I got 75 degrees going in and 174 coming out. I couldn't believe it. I put in a fan but it will work fine without one. The rising heat will pull in the cooler air. I am going to install one on the south end of my house through an open window. The one I made is about the same size as yours. The one I will install will be almost double that. Thanks for the idea.

If you think of this system in terms of how you would build a passive house you would insulate the box and the hose. Stopping heat loss on the box and hose would net higher temps and be more efficient.

Thank you for very good tutor , I will going to try how it's working

Great! and a great thanks for all your DIY shared video's.

If you had a thermal mass in your home (cob or adobe maybe) to store that heat you could warm an area to a max temp during the day and it would slowly cool through the night.

Very Interesting :) There's hope for daytime heating for my van this winter :) Thanks!

looks like a great idea.

Desert Sun is a cool arsssss son of a gun!!! Thanks for all you do!!!

Best design I’ve seen so far. Thank you for sharing: ) simple yet effective

You should insulate the box if you want to use in winter time.

Excellent work! 👍🏾 👍🏾

Out of all the designs you built, which one would you say had the best heat output?

According to an online calculator, this puts out 10,541 BTU in its current state. Thats based off a Temperature difference of 122 F and a mass flow rate of 80 CFM. You should do a follow up with a vent connected to the inside of a home, so the inlet temperature will be around 70 F.

Nice invention dude. 👍👍

Good video! Seems I saw (and made one) this basic idea in Mother Earth News many years ago...minus the fan. Great idea!

Corrugated steel roofing works as well. Often times building supply stores keep odd length cover sheets from orders.

Try arranging like fins in a heat sink to catch more light and provide more surface for air to flow over. Heat sink has the same goal.

I just take all these builds and look around yard to see what can be used , I have a 4x6 greenhouse and first before I cut supply and returns in greenhouse I want to test things like I just built a box with screens and vents and think I might just use all this extra black 1/2 drip system black pipe and 1/4 ( never through stuff away ) I have laying around all stacked up if you will under neath screens to fan to create a baffling effect through black pipe , make sure no short cuts for air , that’s my goal for now , thanks for more ideas

Great video man you do excellent work I like all of your videos Great tech stuff I power my whole house off solar so now I can add solar hot water heater and solar heater from just watching your videos thanks for sharing the knowledge

my compliments on your skills! I wonder about the btu output and how scaling it up vertically would affect its top tempture and cloudy day usfullness. Your units heat output on all but heavy cloudy days might be a pleasent surprise.

Very nice video thanks for sharing!

I reckon this is just about the BEST channel on you-tube. Thank you sir for bringing us your useful videos - God bless you.

From my old days in engineering, before I switched to business, I think the "volume" of air is what's the biggest factor to consider with larger units. Our Co. Tech works the same way, the more air moved the better efficiencies) 2 fans putting out 170, vs 1 putting out 250? (ouch? That's HOT! Great if you could store that heat for later too!) Anyway- 2 Sounds to be about the same area covered as 1 big one. Was the glass cheaper/sq ft? Can/did you put on a bigger fan to move more air? I was thinking of taking out 1/2 of 2 windows of an apartment and putting a collector in their place. You could then easily recycle the air. Just place it outside of the window channel so you can still slide the other window for fire escape. Making some sort of air movement baffles would help insulate it when not in use. Layers of light plastic sheets that lift when the fan blows? Oh yeah,would have to create a cloned 2nd open area at the bottom to input and distribute the air. Another idea is to make fake Shutters as collectors? BTW- Has anyone tried corrugated sheet metal roofing yet? Really cheap.

This device would be excellent for drying clothes here in brasil! Thanx for the idea! 😆👍 💚💛💙

Well done!

If you sand a piece of charcoal after you’ve painted whilst wet onto the metal fins and inside the box this will increase surface area by x 2000 and gather more heat.

love your use of a jbox round for the hose.

I have several similar units I've used for heating my shop. It supplements nicely. A couple things to note.. Don't use inside air. Using outside air, and a bigger fan does reduce the output temperature, but creates a positive pressure inside the house. Which is what you want . Second is, don't ever cover windows. Defeats the purpose . Make a simple wood cover and place over the glass during the summer. Realize that anything wood, especially regular cut 2x4s will warp and let a little dust and water in ...and heat out. So focus on a weather proof material. Stain the outside, marine plywood is by far the best option. Regular wood is okay, just realize it's a 2-3 year life span. The wood will fail first. Tempered glass is good, use a patio door or just 1 layer if you have it. Go cheaper and do more surface area. Units get so hot they'll cook a lot of other materials. I use a temp controller with a probe inside the unit. Kicks on around 88 degrees and pretty much runs all day 500 cfm at 114 degrees... using outside air which averages 20-30 f. ( I'm in northern Utah). It runs when its 0 degrees on sunny days, no problem. Get a good baffle that closes when the sun goes down. Basically bigger, cheap and dirty is the best option inmy opinion. If you try to create the most efficient unit, but it costs too much, is too small or gets too hot and cooks off, you're not going to see a return on investment, which takes a year or two.

Try using the inner plexiglass from an old big screen projection tv instead of glass. Its magnified so you'll also need to make a metal frame and possibly thicker gauge metal inside but the heat those generate is insane.

How would you go about making a flexible version? Maybe one made of clear plastic that kind of “inflates” when air is pulled through it-for lightweight applications

Interesting experiment.

This is so cool! I wonder if I can implement that in my van build when I get one?

Thank you for the video !!!

nice i have a skidding glass door i been thanking about making one out of it

If you could build exerts units Maybe you could run the excess heat into maybe a ice cooler or something larger, filled with say river rock to store heat

Outstanding!

Hello, Great videos. I would like your advice if that's ok with you?. Can you advise me from your experiences which diy solar heater would you say worked the best and got the hottest during your experiments?

Good job.

Great Project! Thanks for sharing! Just curious? Have you tested the difference in temp when it's cloudy out? I'm sure it will still warm up but just curious of the difference.

Is this model more efficient than the ones you did years ago ?

The fan could become a means of temperature control by breadboard or Arduino to control its speed, less speed less heat.

I wonder if adding some heavy rebar inside the glass would help build mass for more radiant heat?

What is the measurements for this project

Fantastic video

Love IT! 👍

Making a Jerky Dryer using the panel as my power source. Jerky takes about 4 hours to dry and my area only has propane. Not very economical to say the least. I'll keep you updated. My only concern is when you seal the fan inside the unit you subject it to the internal heat when not in use and it makes it hard to change out if it fails. I'm putting my fan on the outside in a small mounting box. Just a thought

You can use cardboard boxes to insulate the box. Just cut and tape inside the box. The cardboard boxes are free from the stores. Haft of inch of cardboard boxes could provide up to R5 insulation to the box. The temperature inside the box will be higher as you add insulation to it.

This is a really awesome project 🤯 really opened my mind wow 😯 I love the way you conducted the video too. My only thought was about possible fumes from the sun-heated spray paint venting into the house perhaps? Amazing work 👍👍👍

Would a sky light in the roof be equally as effective ?

It's obvious to say that temps are higher if the intake is brought in from the inside warmer house air vs outside cold air, but I haven't seen anyone do a design that has say 3 connected in a series where the you have hot air 160 degrees going into the 2nd, and then out again into a 3rd. I wonder how hot the 2nd and 3rd air temps would measure.

Great amazing job !

You are doing a great service to humanity sharing valuable knowledge, thank you!

Wonder how to use this with thermal mass or sand battery. I live in an area that is a lot colder at night and very sunny during the day. Awesome DIY!

what if you "vented " both sides so the incoming air is already warm and just re heated ? then your fan could be on the "cool" side ? I'm with M Langford on this one :-)

If you incorporate 2 of the solar panels inside the heater either side of the fan. Do you think that would work?

Best one I’ve seen.

what if you reused the heat it produces like central heat for say an RV, instead of sucking in outside air just recirculate from where you are heating.

I am wondering what is the measurement of this heater & how much square footage can it heat up? I am thinking that this is one of the best idea to keep green house warm enough?

How about if the hose was sprayed black, you insulated the internal of the box and then used a slightly black tinted Perspex. All helps with heat absorption and would produce a potentially higher heat output. Run the fan at 1/2 power that would leave the air in the heat box for longer potentially resulting in even more heat being produced.

Thanks for doing the Celsius too. :-)

Hi, I'm looking at making a solar hot air box and I need your expertise advice, would using onduline bitumen corrugated sheeting be OK to use?

Bravo et merci le ventilateur est indispensable

My like to the video for the description completeness

I've watched your videos. Thank you....I'm wondering what you think is the best design for a window solar heater.

Try black correx,it's like for sale signboard with finer chambers,boils almost instantly in strong sunlight!

Smooth drier pipe instead of the flex pipe should improve heat output. I like this cleaner build over beer cans! lol

What if you had 2-way mirror mylar on the front to help trap the heat?

Could you have a small solar panel to run the fan that would just run the fan when there is enough sun to power the fan? That would eliminate the switch then.

Dude get that copper pipe that has fin's on it. Make Gallium Aluminum Scandium alloy and fill the copper pipe and sweat everything together and snake it through the bavkside of your solar heater. The Gallium Aluminum Scandium alloy will absorb and conduct the heat for hour's after the sun go's down. You can also take advantage of drafting and heat your home or green house. 😀👍

how does this thing work on passive mode during winter ?

Impressive :)