Hey folks,

I just finished my solar hot air heater. I won't be mounting it until the fall, since spring is already here in Arizona. I measured the outside air temperature at 77 degrees Fahrenheit yesterday, while the air flowing from the outlet vent on the heater reached 159 degrees Fahrenheit. Then the thermometer quit with an error.
I'll post up some picts soon.

I've put off building my projector until the heater was done.

That sounds pretty cool, how large is this thing and how big of an area will it heat?

And how about cost?

There are huge advances in solar being developed right now.. this is a very exciting time.. in 5 years solar power will be competitive with fossil/carbon based electricity at .80-$1/watt. in a decade it will undercut these costs by half or more... 30-50 cents/ watt..

There is a new thin film solar 'panel' being developed (as thin as a piece of paper) which will be commercially available by 2009. Its 200 times lighter than any glass based panel, and can be mass produced in large rolls. You will be able to cover entire buildings or roofs with it without need for support. It is based on a CIGS semiconductor compound that absorbs light by freeing electrons. This is then embedded on the polymer base. You should be able to power your entire house on a cloudy day with half your roof covered in this solar material.

here is a solar heater I found

http://www.instructables.com/id/EMU06ULZ1MEY95WRNU

Hi, Cornbread here is some info. The panel is made from a sliding glass door. I forgot the exact measurements--I'll look them up and post them. Similar versions say they heat an 800 to 1000 sq foot area. I made some modifications, so I don't exactly know.

I was inspired by a few articles in Home Power Magazine and a few walks through the Home Depot. I liked the design called the cansolair, but did not want to buy one.

http://rochsolartech.itcstore.com/default.aspx?p=110303

Then, I looked for a design that someone might have made using the same ideas that sprang into my mind. I figured someone else would have thought the same thoughts and designed something. Therefore, I typed solar hot air heater into Google along with the words aluminum dryer tubes, and a cool site came up with instructions. My design is a little different, but Wayne Langille's solar hot air collector was similar. So, I used it as a starting point in building my panel.

http://www.atlanticenergy.ca/projects/Wayn...72/Default.aspx

Here is my panel just leaning on the wall outside my classroom for a science experiment. Next fall I'll be mounting it to heat my house.

Also, here is the thermometer before it stopped working at 159 degrees.

Hi tameone, I still have to do the final math, but I think it was just over 200 dollars and about 30 hours of work.

Sliding glass door was free.
1 @ 1.5" polyiso foam $28.00
1 @ .5" polyiso foam $6.50
2 @ 10' u-channel galv. steel construction 2x4 holder things from Home Depot $8.00
2 @ 4"x10' flashing $14.00
2 @ 3"x10' white flashing $12.00
2 @ 10" galv. metal duct box-like covers $8.00
5 @ cans bbq 1200 degree black paint $25.00
9 @ aluminium 3" dryer ducts $72.00
3 @ tubes high temperature sillicone $30.00
1 @ bag of rivets ?
25 @ self-tapping screws ?
There might be a few odds and ends I might be forgetting, and these are the rounded costs as I remember them. They should be close to the real total, however.

Very much looking forward to your DIY article- this looks great.

Hi,
Here is a shot of the u-channel. I think it holds metal 2x4s to the foundation of houses. It is about four dollars for a 10 foot piece.


Here is a side view close-up. I just needed two pieces of u-channel.


I used my dremel tool to cut two 45 degree angles. Then I bent the piece with a wood block into a 90 degree "L" shape.

I drove my dad insane with my slow precision. He's a get it done now, person, and I want it to match exactly what I have pictured in my mind's eye. It was neat working with him on this project now as an adult. I should also note his practicality helped in other areas of the project.

Here is a shot of the 1.5" Polyisocyanurate foam and the "L" of u-channel that fits on top.

Here is the corner detail to increase strenth of the box.

Dryer ducts painted black and inserted into drilled holes in the vertical pieces of polyiso foam.


Here they are moved into place.

Top box will collect the air.




A view from inside.

End view of tubes with bottom flashing attached. Bottom air collection box about to be assembled.


Bottom box attached. Side "L" shaped u-channel about to be attached.

Sliding glass door attached to the top of the box.


Here is the corner detail where the door is attached to the metal box. The black you see is high temp silicone.

You can see the bottom flashing in this shot. Now like a sandwich white flashing will pull the top down toward the box and the bottom flashing. Screws will secure it in the sides of the box.

Done

Hmm? Say what, that thing looks nuts. More info pls. =)

The heater is 80" tall and 36+1/4" wide and 6+5/8" deep. It worked out nicely since the flashing and the u-channel both came in 10' lengths. One piece made the top and one side while the other piece made the bottom and the other side. There were a few inches to spare so they were folded into/over the other "L" it made them interlock.

There is a company called Sun Lizard in Australia that has solar heaters working double duty. They heat in the winter and then in desert environments like Arizona they can use them as an atmospheric cooler. In the early spring and fall the desert gets cold at night since we don't usually have clouds. The heat beams back into space. Their idea is when your house is hotter than the night sky the black heat absorber becomes the perfect heat radiator. (I don’t think this will work too well in other parts of the country.) So, I'll be giving that a try in the fall. I have an energy_star, through the wall, bathroom fan that will be connected to the heater with a snap disk switch. I plan on mounting the heater on my flat roof above my patio. (I'm going to get help for that.)
Here's a page with Sun Lizard info... they have a neat solar fan on their design.
Sun Lizard Solar Heater & Alt fuels

Here is a Sketchup animation of the rigid foam with the tube holding frame on top. The glass door and the flashing are hidden in this view. With the heater done, I actually worked on my projector this past weekend.

http
://d2.mediastreamnetworks.com/videohos...p;ssvh=193

Here's the Sketchup view with the glass door on top the prior animation was done without this part. Later I'll post a drawing showing how the flashing pulls the parts together.

Well, now that there is a chill in the air here in Arizona, I've started the process of intalling the heater. For the past two weekends, I've been working on the ducts and installing a fan. I'll get some picts and get them posted. Right now I'm looking for a cheaper place to buy the steel that mount garage door openers. I think that is what I'm going to use to mount it to my patio roof.

Davis salvage. Lots of steel. Washington and about 38 street.

I'm not sure about using any plastics in AZ in the daylight in the summer time. I would think the temp will get over 250deg.

We do cook on the sidewalk here you know.

I think this is the solar cells your are talking about.

http://www.nanosolar.com/

It is worth noting that no where to they list the life span or the the power per square MM or foot. It does look like they will be cheaper but they will have to be able to be around $00.10 per Kwh if they want to be king.

I'm in AZ too. Phoenix.

I wounder how hot the air might get in the summer time? Could I feed it into the dryer? That might actually save some cash off the $460 electric bill.

I wounder how hot the air might get in the summer time? Could I feed it into the dryer? That might actually save some cash off the $460 electric bill.
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Good thoughts on the dryer. All I thought of was using it to make fuit roll-ups. Really though, I'm going to cover mine in the summer and disconnect the vents.

so, what does airflow look like in this? Is it just in the bottom out the top? Or is it more complex?

Hi,
There is a collector box at the bottom and the top. An air duct will pour air from the house into the lower box. All the vertical tubes connect to this box and the top reservoir. Convection, when the fan is off, will move air bottom to top, but the trick is the flow in the tubes. I left the tubes partially folded to allow the air to tumble. So, they are not smooth. On the comercial hot air boxes they install baffles to force the air to tumble and mix up. This rolling of the air is what helps transfer the heat from the surface of the metal to to air. I really liked the "Home Power" multi issue article on hot air heaters. They showed 3 types. Mine follows the one type where the air is kept separate from the absorbing surface. No filters are needed to keep the black absorber clean. When I had it in the sun last spring, it roared to life without any fans. When it is installed, I'll have a snap disk in the ducting near the top. When it is warm enough, the fan will kick on and force the air out. Then, as the temperature drops the fan will click off. The Canosolar inspiration I modeled my design after seems to work well even in places like Rochester, NY. Also, There will be a back draft blocking vent since at night it would want to suck warm air out of the house and transfer the heat to the night sky.

Hey everyone, I've been away and busy, so I wanted to update you with the installation of my heater. I wanted to install it on my roof but ran into some problems. Well, here is the new installation.




Here is the wood rot and why my plans changed.



I had to fix that and I would need help installing the unit on the roof. I really wanted the unit installed to take advantage of all my earlier hard work. If I waited until my roof was fixed, there would not be any need for a heater.

I used seven foot fence posts that have a t-shape. It forms a nice ledge to slide the box into. I have one on each side and used rope to secure it in place. Being ground mounted it should be easy to cover up and unhook for the summer. Then next year I can move it to the roof.

Here is a close up of the fence post and a view of the outside temperature about 63 to 64 degrees. It was cloudy today and the inside temperature was quite nice.



Here's a shot of the clouds reflected in the glass. Also you can see the dryer duct that I insulated and installed. I used fiberglass wrap and foil tape, but otherwise it was an 11 dollar dryer kit.

Lastly, here is a shot of the inside air temperature. Note, I need to prop open the vent with toothpicks, but otherwise it works well. Today even though it was partly cloudy it was pumping out 101 degree air. The other day when it was sunny it was cranking out 134 degree air.




This was going to be the through the wall fan that was to push air through the panel. (low power energy-star) Now it is re-puropsed to take the warm air out of this room and push it into the other part of the house. I won't have to move it when I install the unit on the roof next year. I'll just need to duct the output to the hot-air box. Also, you might be able to see the pencil marks on the wall. The directions mentioned clearance, but they had an error for the top clearance. The template they give you will fit but not the box you install later.

Now, I can get back to work on my projector.

Hi Arizonavideo, I must have missed this earlier. Thanks for the metal supply advice. Regarding the plastic your advice it very valid. My heater contains no wood or plastic. The polyiso foam is a high temp foam. Regular foam would melt in a bad way. The silicone is also special--high temp rated--in fact it had food contact ratings on the tubes. After installing, there has been no smell or anything from the heater. Wood should be avoided on these types of projects due to pyrolysis. A process of heat breakdown of wood that will over time lower its kindling temperature to something so low it is frightening.


I've also thought more about possible summer uses. If I had a insulated metal shed and a water heater connected in the back near the heater, I bet it would work well enough here in AZ. Not very efficient but when the days are so hot anyway I think it would work. I don't know if the heat would last for a morning shower, however.

I'm curious about adding packing into the heater tubes, like steel wool, so the air has more surface area to absorb heat from...

Also, Legionaries disease? Any chance at all?