home made solar panel

[cp-connection]

I was surfing the nets and discovered forced air solar panels. They heat air instead of glycol, oil or water. They are very inefficient but they're also really cheap to build and operate!

A $100 panel will heat a large room on a sunny day. I will post updates and pics!

 

[SDCPs]

I like solar panels...IMHO they are only practical in off-grid places at the moment.

 

[cp-connection]

Well, today is the first day with my solar panel installed. I turned off my furnace at 9:00 am. It was about 35F outside/ 60F inside.

9:30 am the solar panel fan began pumping 70F air in through my living room window.
11:30 am the solar panel was pumping 130F air in through my window.
2:00 PM it is 55F outside, 71F inside. The air from the solar panel is probably in the 150F range.

This is a test panel that is 1/3 the size of the one I will have next year. I need to figure a way to have less bends in the ducting to increase air flow. This will increase heat transfer and lower radiant heat loss out of the face of the panel.

Constructing the solar panel:

Solar panel installed, ducting through my living room window:

Finished solar panel:

 

[adnedarn]

Pretty neat, how about having the dryer tubing go up and down, that should be less turns than side to side I think. Could probably even just change that one, it'd take the same amount of tube.

 

[Av8tor1]

Couple easy recommendations to increase the efficiency of your design,
1. Paint the hose flat black to increase absorbtivity (paint on the outside) and emissivity (inside if possible)
(medium and long wave infrared radiation is reflected away by the shiny surface, this is the idea behind those mylar emergency blankets)
and paint the inside of the box (or cover with mylar) with a flat white paint to increase it's reflectivity and reduce heat loss due to conduction and IR radiational losses.
(medium wave infrared radiation is reflected away by the white surface)
2. Make something to swirl the air as it travels through the tube. (prevent any laminar flow, and thermal transfer is directly proportional to temperature differential)

I use to do the Energy merit badge project for the local boy scout troops, one of the projects I had them do was to make solar ovens

Av

 

[adnedarn]

Also, is air just coming int he bottom of this thing? What if you had the other end of it, come into your house as well... Far away from the blower though, so it is sucking in your 60f air to start with rather than the 35f air. Dunno how much of a difference it'd make though. I had saved plans once for a nice looking one... But don't see it in my favorites right off the bat (did find some stuff I saved some 10 or so years ago though! LOL)

 

[cp-connection]

That was what I was going to do originally but I thought it would decrease efficiency to force hot air down. I would like to try that on my next one though.

The vent is painted black, its hard to tell in the pic. I assume there's quite a bit of turbulence inside the vent because its made of a spiral wire and textured foil. It's pushing house air into the bottom of the panel, then it snakes up the panel back into the house.

I left the door in the back bedroom closed, it's 59F and the rest of the house is 72F!

Thanks for the comments!

Pretty neat, how about having the dryer tubing go up and down, that should be less turns than side to side I think. Could probably even just change that one, it'd take the same amount of tube.

 

[chezilla]

Do you have a link to that site? Thanks.

 

[cp-connection]

I just watched some you tube videos and cruised http://www.builditsolar.com/index.htm . It is loaded with DIY projects. Then I did my own thing.

The you tube guys are making these with lots of glue, pop cans and tiny DC fans with preset thermostats. I think there isn't enough air moving through to adequately vent the heat. Any heat that builds up in the box will radiate back through the face. There are almost certainly hot spots if you make manifolds and vertical tubes like those guys do. Also, if your thermostat cuts on at 120F you're missing out on 2 hours of morning heat.

 

[F R e N c H 3 z]

I need to figure a way to have less bends in the ducting to increase air flow. This will increase heat transfer and lower radiant heat loss out of the face of the panel.

I would consider placing the ducting long ways rather than from side to side, that way you would minimize the bends. Just an idea...

 

[cp-connection]

I would consider placing the ducting long ways rather than from side to side, that way you would minimize the bends. Just an idea...

If the panel was positioned horizontally rather than vertically I could run the ducting long ways but still have the hot air flowing upwards. It would be almost 1/3 the amount of bends as the original. Nice!

 

[F R e N c H 3 z]

Just realized Andy had posted the same idea before me -.- I really shouldn't post late at night.
Great minds think alike though right

 

[MiguelSR1]

not a bad idea at all