Those strips of 1/4 inch wood used on the screen is called furring strips, and before you put the screws in drill holes for the screws (slightly smaller of course). That will keep the wood from splitting like it did in the video.
I really dig your version on this project. I have reviewed many versions. I wished you could have shown the installation from the inside of the window, in the house. If possible could you show next time. Can't wait to see your upgrade model. I've selected your project to install one for my green house during the winter months. I grow organic produce for my family. You've been blessed..nice going LDSreliance.
Thanks for the feedback! I regret not showing how to install it in the window. I'm afraid that it would be different for everyone due to the height of your window, the width of the opening, and what materials you have to create an adapter for the window that the unit can protrude through. I hope I can build another one as it is now getting colder here. Stay tuned and thanks for watching!
Plan for this same heater was published in Mother Earth News somewhere between 1978-82. A friend made one using a glass top and three pieces of plywood with the glazing on top over flat black plywood. It measure roughly 2 ft wide by 4 ft long. The facility where I worked had a cooler where food products were stored. We brought the panel and did a temporary install to test it. We achieved a 20 degree difference on the air change pulling 40-degree (F) air from the cooler (bottom compartment) and witnessing 60-degree (F) air exiting the top glazed compartment. As I see it, what this first design lacked was a baffle that could be closed at night to stop the process, which may very well reverse at night. For the slow passive air exchange, I'm not sure the inconvenience of uninstalling it every night is a good idea. Perhaps just a block of foam to fit the window opening from inside the structure could serve as a shut -off at night.
Good points. I was seeing higher than 20 degree F difference on mine but mine is larger. I tested the backwards passive at night and it didn't happen. There was no siphon effect so there was no air movement at all. I did not see fit to create a baffle but that would be a great solution. Just a simple flapper that you could close at night would be sufficient.
You did a great job on how to build a passive solar heater window unit, I will build one just like you did except for the screen, Instead I will use two layers of black shingles that I have extras of and let the sun heat them. 2 thumbs up on your design.
It won't heat a large space but if you had a bedroom or workshop or something this type of heater could really make a difference. You are welcome. Thanks for watching!
Wouldn't the outside temperature negate any gains of the warmth created by the sun? I'm going to build a passive panel but mount it on the inside of the window.
Your window will filter most of the UV radiation from the sun so it won't operate very well. The outside air temperature does fight against the heat but with clear skies and a nice, black interior that box gets pretty hot.
It wasn't meant to be that kind of build so I didn't make a materials list. I adapted the design and materials to what I had available for my budget. Sorry about that. Here is one of the websites that I used as inspiration for the build: www.builditsolar.com/Experimental/AirColTesting/ScreenCollector/Building.htm You can also check out the build I did a few years later that might give you more ideas: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-znytJtU0za4.html
Nice video. Did you make an updated version? If not could you send me instructions based on your experience. Also ..does the angle of the box against the window make a difference?
How did you connect it to the window? I didn't get that part from the video. I got the "angle", but how did it actually connect? Open the window? Did you build in insulator boards on either side (a la a window A/C unit)? Thanks for any clarification. Great idea - love these DIY videos
It connected just like a window unit air conditioner like you said. I cut 2 pieces of wood out, one on either side, and then used foil tape to seal the gaps. It was not perfect but it worked. Thanks for the comment and feedback!
The screen is what is absorbing the sun's radiation and then warms up the air as the air passes through it. A lot of people also build these using soda cans that are painted black. As long as it is black and air can move through it, it will work. The angle definitely affects the efficiency. Unfortunately, with mine I couldn't really control the angle due to my design choices. If and when I build a new one (maybe this winter?), I will take that more into account to allow some adjustability or design the optimal winter sun angle into the design given the height of the window that I am using to draw the air in.
Great video have you thought about replacing the center baffle with just black sheet metal so would act as a heat sink and my other question was have you tried this band forced him to see if it would perform better?
I don't think forcing air through the heater will improve performance. It would certainly move more air but the temperature of the air would decrease because it wouldn't have as much time in the box to heat up. Also, you would have to run some wiring (which my wife would hate!) to the fan and it would start costing you electricity to run the thing. My whole idea was to get free heat (other than the price of the materials to build). I hadn't thought of replacing the screen with sheet metal. It would work really well if it were baffled somehow because you really need to force the air to come in contact with the "heater element", which in this case is the screens. Screens have lots of holes and allow air to move freely through it to generate a lot of surface area to transfer heat. I don't know if just a flat piece of sheet metal will allow the same transfer of heat.
Did I understand correctly, is that pressure treated wood for the frame? If so, toxic chemicals are off gassing into your air. Also there are always people giving away free sliding glass doors on Craigslist that make great covers for this kind of project.
Nice job men. I really like it. But I have a question. How can you be sure that the outer wooden board will not be destroyed from either the rainfall or the air humidity during the years? Why didn’t use for example aluminum?
I wasn't building something that would last many years. This was just an experiment and proof of concept. I had seen these plans on various diy sites and was a bit skeptical. And, while they can't heat your whole house, they can certainly lower your bills or cut your use of firewood down in an off grid retreat or cabin. If I was going to build something like this for long-term, I would put some wheels on the bottom, make it much wider, and use galvanized or treated/sealed materials like you said.
Haha, I didn't know anyone was still watching this. No, I don't still use it but I did make another version the next year to see if I could make some improvements and changes. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-znytJtU0za4.html
Will these are great examples, I am curious though are you using any of these systems to produce heat in your home and are they efficient. I've heard that people make these for their ice shanties in Minnesota and apparently they work quite well but I've not witnessed it personally.
I don't know. It is a drop in the bucket for a big home like mine. All of my south-facing windows on my house are on the main level, which is about 2,300 square feet. I was not able to ever figure out how much quantity of heat was transmitted or measure an effect on my overall temps indoors. In a yurt or a shed or a small outbuilding I do believe one of these of this size would make a meaningful difference. Not 20 degrees difference. But a difference. And maybe if you super-sized one that covered the entire side of the house that faces south with unobstructed sun all day it would make a difference. I know that solariums in off grid homes have a huge impact on indoor air temps and act like a battery to hold warmth well into the night as well. But those are much, much larger than one of these small devices. So keep that in perspective.
It should face south if you are in the northern hemisphere. That way it will get sun exposure all day. I put mine on my family room window facing south.
Thanks for the video. I would recommend setting up a link at the end of the video to the results video. I had to go digging into your channel to find it. A quick link would have been helpful. Still, thanks, I'm going to give this style solar heater a try. Cheers
I made several. They work yet in my area of NE Ohio there was not enough sun to make a real difference. I want to emphasize that they do work if there is enough solar gain.
Yeah mine worked and the air coming out of it was very hot but it wasn't able to put a dent in warming up my family room. I am going to try to work on a bigger and more efficient one this winter.
I like the simplicity and passive features here.One thing that occurs to me: since you also will have a need to clean the dust out of the air when doing woodworking, why not have fresh air coming in and have a separate vent system for dirty air to exit? There might be a way for the wind to help, like on a chimney where the Venturi effect tends to pull air out to prevent buildup of carbon monoxide.
You could use fresh air from outside but then you run the risk of having critters enter the outside intake. It would also bring in humidity from outside. You would have to have an equal possibility for air to exit the house, too, or else the intake wouldn't allow much, if any, air to enter a closed system.
I appreciate your feedback - but in my situation there wouldn't be any significant difference in the humidity outside to inside. If critters were a problem it would be a simple matter to put metal screen on the intake. Your question about outflow is already answered by the aforementioned chimney Venturi effect causing airflow not only from heat rising, but from crossflow of any outside wind.
So why did you bother using the foil-backed plywood on the bottom of the collector box if youre just going to cover it with the foam board? Trying to understand, not finding fault.
Good questions. I did not measure the cfm but it was low. It was similar to cracking the oven open about two inches with the oven turned on to 200 degrees F. You would feel warm air rising up around you but it doesn't move very fast. I am planning on doing another build like this in the next few months and I will do a better job of gathering raw data for you. Sorry about that.
Obviously, the outlet goes in the window. Where's the inlet? Does it draw cold air from OUTSIDE? If so, it would be much more efficient to draw air from the house to be reheated. Which may be more difficult with your design....
+romansten9 No, both inlet and outlet draw air from inside. The inlet is right below the outlet separated by a piece of wood. The inlet draws air from below and the outlet exhausts warm air into the room which immediately rises. I could put my hand above the outlet about one foot above and feel the warmth really well. We aren't talking big quantities of hot air but it does work.
Nice work! Good concept! I like the use of the clear polycarbonate panel as an option rather than glass or some sort of a window. I like all the caulking and insulation ideas for sealing the box up good with little to no loss of heat from the box itself. I might use black tar paper (that's what they use under the shingles for roofing, in case you didn't know) for the backing of the box, minimizing the need for much of the black paint. I would also use a dryer vent, fashioned like a snake, weaving up and around the inside box (painted black) rather than the soda cans most use, creating a natural up and around airflow heading up the top. I would attach tubing to the end of the vent to be fed through a window a "sealed" open window that I would build a wooden box/frame for to lower the window onto with appropriate seals. Somewhere inside this tubing TO the window, FROM the box, I would be placing a small solar powered fan (maybe barely bigger than a CPU fan on a PC) to draw up the hot air from the heat box. I would then put 2 smaller air flow tubes (for the cooler air) to draw air OUT of the house (from the window box) to the BOTTOM portion of the heat box. This creates a natural air flow. This concept might lead me to build a DIY air exchange system where I would draw out or exchange the moist and musty air in the basement for dryer, fresher and heated air from outside or from the box. Having a steady temperature in the house is better than a musty lower level and an overheated 3rd floor with perfect temperatures in the middle floor. Man, I'm anxious to try this out! I can hardly wait to get my OWN house to do this in. I currently rent 1 side of a duplex with my girlfriend so we can only do so much. I am looking forward to putting this all together. I also need to find and fix the leaks in this place now as we will MORE than likely be spending yet another winter in it with 100% electric heat. And to think it's supposed to be a worse winter here than winter of 2014!! I LOVE the northeast! Thanks again for the ideas in this project.
+Lee Forex I feel your pain man. We have electric heat here, too, which is why I started tinkering with these kind of heaters. And if you make one like this you could even use it in your duplex because it requires absolutely no permanent modifications to the house. You just set the outlet/inlet inside the window and then close the window on top and seal around the edges with foam or cardboard or something. It produces REALLY hot air but in small volumes. If you put powered fans in it you will get a greater volume of air but it will not be as hot. Good luck with i!
So will building these boxes WITHOUT the use of a fan be able to have enough air flow to "project" the warmer air into the other side of the room? The other thing I was wondering is... Like, I know in summer when it is hot, if we don't use the A/C on the 2nd level it is HOT well into the night as the heat from the day rises to the 2nd level and gets caught up there. I wonder if we bring the heat in from the solar box during the winter if the same deal will happen as it does with the heat trapping and staying upstairs all night. We can't even sleep comfortably upstairs at night, after a hot day, and it is hot upstairs ALL night without using the A/C. It' cools off at night, nicely to the 50's (F) but even using a fan in the window to attempt to draw in cooler night-time air will not do a thing. So my HOPE is that we will have the same "problem" of not being able to get rid of the heat that finds it's way upstairs during the day because we won't have any sunlight to continue the heat from the solar box at night. I wonder even further if the lower we draw the air from, i.e. from the basement, then into the bottom of the solar box, the better the air flow will be? It's always freezing in both the garage and the basement. I plan on building at least 4 boxes, all 4x8 using composite decking 5/4 board, as they say, for the lack of maintenance needed. Thanks for the response, btw. Lee
Lee Forex The reason the upstairs stays hot all night is because the entire house literally soaks up the heat and then slowly releases it all night. Think of when you cook a lasagna in the oven and take it out. It can still be too hot to eat in the middle 15 minutes later after you take it out. It takes a while for it to release all that heat from deep inside. Same with your house. All the wood boards and floor and roof and brick/siding soak up heat all day long to well over 100 degrees and then release it all night into the house. You won't be able to generate that much heat with that small window unit. And it will not heat the other side of the room unless you have some air flow movement around in the room like a ceiling fan or something. This type of heater will slowly heat a small room over a period of several hours maybe 5 degrees max in direct sunlight with the right angle toward the sun.
+Lee Forex DON'T use tar paper. Heated tar paper will make your house STINK and probably emit toxic fumes too.And It will fade badly in a few weeks at most. I think metal roofing painted black might work. Ever touch black metal that's been in the sun ?
@@meauxjeaux431 and gang, using corrugated metal roofing in the collector has an added benefit in that the curved corrugation has more surface area in the same space, allowing for additional heating. In the solar collector I'm building, I'm also making the outside curved to take advantage of the sun tracking throughout the day, and fire bricks to store the heat to release after the sun goes down for the day.
You also used the wrong screws to fix corrugated sheet. You should use three part clamps that match the curve. That’s why the sheet is kinked and will split after a while.
I didn't have a place to store it out of the elements. It was getting rained on and so I salvaged the useful parts and scrapped the rest and built a new one that was smaller and more efficient. Check it out here if you haven't already seen it: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-znytJtU0za4.html
First Last The air will naturally rise through the box and drift into the house on its own. No fans or trickery needed. It will pull cooler air from the house into the bottom slot and it will slowly move through the heat elements (screens) and then up the top side and back into the room. See the results video for an exact temperature measurement of the air moving into my living room: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-qZThJKIcRz8.html
LDSreliance No, I got the principle of cool air, warm air, etc ... and I promise I'm not trying to sound rude, but I see people going into great detail on the angle of a screw or the construction of a nail, but no details on how to stick it in the window. I mean, I could probably figure out something on my own, but why not see what works for other people first?
Oh, that is what you meant. I didn't bother to go into that because every house is going to be different. Some people will want to permanently mount it, such as if this is for a workshop/garage/shed. Others will want to mount it in a window and then remove it when it gets warm. And all windows are going to be different sizes and shapes. For mine, I just put the inlet/outlet inside the open window, shut the window down on top of it and then fashioned 2 side pieces out of cardboard and insulation to plug the holes left on the 2 sides. Then I used metal HVAC tape to tape it all up and minimize any gaps for air to get in. It wasn't perfect but it worked. I probably could have taken more time to design something out of wood but I chose not to.
With solar heater that are available in your own home, saves you time, money and energy... thats why you can enjoy hot water, warm room in cold months without worrying about your electric bill..
I think plexiglass would have been a better choice in the long term for the top. That clear roofing piece you used will become very brittle in a few years. I used a couple pieces of this on the roof of my chicken house to let in some sunlight and it has become very brittle after about 4 years and needs replaced. As a bonus, the plexiglass would lay flat and you wouldn't have that little gap.
+Darkman Walker True. I would have liked to have a flat piece. My experience with plexiglass is it is easy to scratch and does not weather the elements very well. I was only planning to use that heater for one or two seasons and it served its purpose.
There is a significant difference between plexiglass and polycarbonate also the poly is more expensive. A flat piece of that would be better versus the corrugated.
Brilliant Newfoundlander Invents the Solution! ...........................................................................................................................................................................................watch this guy explain how the furnace works
Nope! That is why I tried again the following year to make another version that was really cheap but hopefully just as effective. Check it out here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-znytJtU0za4.html
The screens are what absorb the energy from the sun and heat up to provide the heat transfer to the air. Screens have a lot of surface area so they are ideal for this since the air can move through the screen freely.
Unfortunately, this is not a solar panel that can generate electricity. A thermoelectric generator may be able to produce a small amount of heat during the daylight hours with this.
thanks I got my cans painted black today. found a vid w a study on which type of hole was best at the end of the can producing more heat. they said nail holes beat larger holes at bottom of the can, if you can believe that. I think maybe the air stays in longer gaining more heat?
Yes that is a great point! You don't want air moving through this type of device very fast. That is why I chose not to use a fan (that and the wiring mess). In my head, the smaller holes in cans sounds better but I think you'd have to test it out. Do you have a link to that vid?
hi I am a Mechanical Engineering student and My Instructor gave me same task to design and calculate also model this type of system mathematically and also drive equations of efficiency, heat transfer, thermal circuit. will you kindly please share details of this project with me I will be very thankful to you
Um... So this works when sunlight hits it. But it's colder at night. Soooo.... Why is this a thing? Sure it's a supplement, but not a replacement, and it wont even supplement during the period of the highest energy draw from your heating system....
Meep Changeling You are correct. This is a small scale supplement. If you build it in large scale it could heat your home but that isn't practical. Just a fun little project that could save some money during the day.
+Meep “the” Changeling quite so. there are vids I've recently seen which describe how to pack empty plastic milk containers into a flat oblong box. these are full of water which store the heat. I wonder if the ideas in this clip can be combined with the plastic beaker heat storage idea?
Looks great, but we have a dull cloudy day here it's raining and cold that's only going to work if the sun is shining and you may not even need to heat the house. I heat my house for free with a waste oil heater and it burns dirty car engine oil cleanly.
That sounds like a great use for old engine oil. I think you would be surprised at how well this device works even when it is overcast. Now if it is raining and really dark then it won't do anything. But if the sun is out but it is behind a cloud or it is overcast but not dark then it still works, just not as well.
I have made a can heater and it works, but I started to wonder if the cans are really necessary and weather just a black box wldnt be just as effective. Some people say "yeah but with the cans you have a bigger surface", well that mighte true, but the amount of solar energy ('light') falling on/in yr box remains the same. I have seen some people put that box in a window still coz that way they do not need to make holes in the wall. That ofcourse is foolish too coz the window will let in just as much energy as the solar heater will. Your design is better as it adds to a window rather than obstructing it. I know of some indian dwellings in the four corner area who used oildrums, painted black, outside with piping going to their homes as additional heating and apparently that was very effective, or at least significantly cut their energy bills.
Yeah, you are never going to replace a heater with these unless you had your entire roof covered with them. Even then it does literally nothing if it is even partly cloudy. The beauty is that it supplements the heater and creates a cozier space by the window that is drawing in the heat. And if you took your time and built one with good materials and stored it properly during the summer then it would probably last 5-10 years and continue to be a value. Unfortunately, I did not have anywhere to store mine and I made a couple mistakes in my design that caused me to just scrap it in the spring. I hope to build another one using those lessons I learned this winter.
I didn't think about that. Good point. I just read some side by side comparison tests of the 2 styles and the screen kind outperformed the can kind but that is just one test and it could have just been a design thing.
I suppose you could rig up a sliding door or something on the outlet of the heater to either completely or partially block the outlet of heat and that could help regulate its output. Other than that, I don't know how how you would.
A good idea would be to angle the whole device based on your geographic location to recieve best sunlight. Many calculators out there, but look for solar power/sun angle. Heres one I found that works good enough: solarelectricityhandbook.com/solar-angle-calculator.html
True but you would have to build in some adjustability into it to account for the time of year, otherwise it will only be optimal for a few weeks at best. The build was already complicated enough without having to rig up some system for changing the angle. It could be done but you might have to use a fan to blow the air through a flexible tube instead of having a rigid output of the air through the window.
Want to double your free heat? Lose the screen. Don't believe me stand in front of a south facing window on a sunny day with the screen on the window. Feel how warm it is, then remove the screen, and stand in front of the window, and feel how much hotter it is! Also the sun is never hitting the backing that you painted black because it can't get through 2 layers of screen at least not directly. Also use glass not that plastic crap. Good detailed video though!
This has been scientifically tested numerous times by others. I did a lot of research before building this. I used data from a university study in New Mexico as well as a number of websites and government resources. According to what I have read, it will not work as well with simply a black painted wood surface. The two most popular and widely used air to air "absorber" materials are black window screen like I used and black painted soda/beer cans. As far as the glass, it is much more expensive, more dangerous, and actually will not allow as much UV energy through it as this greenhouse plastic. It is actually pretty hard to find glass that is not designed to filter out a lot of UV these days, certainly not at Home Depot or a readily accessible source for someone like me.
these solar heaters really do work amazing ! I just cant watch these guys making the videos, we don't need to see a long drawn out process showing how to screw a screw and then watch you do it. other than watching a stagger slow and BOOORING video it works great
+Balltungo Ball Thermal mass is only used to store the heat for slower or regulated use such as overnight. There is no heat storage in this panel. It simply heats the air and by simple convection, recirculates it back into the room.
If the weather outside is 35 degrees and sunny, your home will still be freezing cold. But you can convert that sunshine into some extra heat for your home.
This was 1. not cheap and 2. super inefficient. Give me a call if you ever need some engineering expertise #MasonInnovation Heat travels through wood much faster than foam, use a foam frame to construct a thermal bridge. No need for the screens. That is what you want to hold your heat. So you need something super conductive, like aluminum foil, with holes. Not an insulator like fiberglass screens.
this video is made by a technically savvy person who has no idea how to explain anything about what he is doing. no explanation of what the screen is FOR. no explanation of HOW this heats air or HOW it is transferred to the house/room. he expects me to KNOW all that, but I don't.
I think he's just trying to educate us newbies like myself and few others who are interested in the concept of solar and the build as a supplement to save some money during the day time on heating bills which I'm sure will work just from the looks of it. It's as best as he can think of at that moment and I'm sure he's open to ideas on how to improve the build if you have any to add besides the negative criticism that you only have now to discourage people on sharing great ideas.
If you want to overcomplicate it be my guest. You'd have to create long channels and zig zag back and forth to keep the air in the box long enough to absorb the same amount of heat energy.
Edward Jones If you don't have the space to work with, sure. But that is a lot of extra effort to get the same result and I have plenty of space in my back yard.
After building that thing, I tend to agree. I built a new one this year that is somewhat less complicated because it is smaller but I made it 90% with materials I had laying around my garage and only spent $20 on the rest. Check it out at: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-znytJtU0za4.html
+Rai Merry Yes, you can build this style of heater with aluminum cans. I think that is the more common way to do it. There are lots of videos and DIY instructions out there how to cut out the tops and paint them and all that. They are about the same as far as efficiency goes but I think the cans require a little bit larger box.
