Almost Free Solar Hot Air Collector

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Introduction: Almost Free Solar Hot Air Collector

About: I cannot throw anything away without trying to find another use for it. as an example I converted a 1984 Pontiac Fiero http://www.youtube.com/watch?v=vrVYEvKvF0A from gas to electric using used forklift part...

I hate throwing anything out untill I have exhausted my mind, searched the web or visited Instructables for other potential uses. I have not found and hot air collectors made from light fixtures so here you go.

Electric Car Conversion;

www.ecosteve.ca

http://goeving.blogspot.com/

YouTube Solar Hot Air Collectors;

http://www.youtube.com/user/EcoGreenGroup

Making a solar hot air collector out of free used 2 x 4 metal light fixtures, free old glass and free black paint to reduce our carbon body tape outline, reduce our untility bills and save money.

We are building and installing 14 of these hot air collectors on our south wall of our 140 year old house in Ontario, Canada. During sunny days in the winter these will completely heat our house for about 6 hours. After we make these, we will join them together venting the cold air from the bottom of the rooms and exhaust the top vents to the top of rooms. The fans will help increase the air flow to these rooms. The next collectors that we make will also be insulated and have a metal baffle inside to help concentrate the heat. The collectors then will be connected to the house and flexable dryer
duct inside the house will vent heat to various rooms . Check out our You tube home page for more info.

• Free Heat.

• No Fuel Needed.

• Renewable.

• Cost effective.

• Green.

• Recycled.

Step 1: Dumpster Diving Time

 
Materials needed
•         Old light fixture (Restore).
•         Aluminum Tape.
•         Flat black paint (Restore).
•         Glass cut to fixture size.
•         Silicone caulking and gun.
•         Latex or nitrile gloves.
•         Protective gloves for handling glass and cutting metal.
•         Hammer and Screwdriver.
•         Metal scissors.
•         Thermometer.
•         Drywall screws and drill with a Phillips bit.
•         Glass cutter and marker (If cutting own glass).   
 

Step 2: Prepare the Fixture Frame

Prepare the Fixture Frame
 
•         Remove old light tubes.
•         Remove fixture sockets.
•         Remove ballast.
•         Screw overlapping corners of frame together with drywall screws.
•         Seal the corners and any small cracks of the fixture with silicone caulking.
•         Cover up all large holes with aluminum tape.
•         Let silicone dry overnight before painting it flat black.


 

Step 3: Painting the Frames

Painting the Frames
•         Wear clothes that you can get paint on.    
•         Wear protective gloves.
•         Put some newspaper down so you don’t get the paint on anything else.
•         Clean the fixtures with soap and water and let dry.
•         Paint fixtures front, back, sides and let dry overnight.
 

Step 4: Cutting the Vent Holes

Cutting the Vent Holes
•         Use a hammer and a screwdriver to strike the “punch outs” at the center of each end.
•         Cut holes square, a little larger with the metal scissors and if installing a small fan to help exit the hot air at the top mark before making hole bigger. you will want to make it a little smaller to allow mounting with the drywall screws (dry wall screws will cut their own threads into the light fixture) Wear gloves to protect you hands.
•         Tape the cut openings after so there is no sharp edges.

Step 5: Intalling the Glass

Intalling the Glass
•         Put silicone on the frame edges so the glass will stick.
•         Then install the glass.
•         If installing multiple panes of glass caulk the seam running across the collector.
•         Let the silicone dry overnight.

Step 6: Solar Panel and Micro Fan (Optional)

Solar Panel and Micro Fan
(Optional)
 
 
•         Screw the micro fan carefully to the top back hole of the hot air collector with drywall screws.
•         Remember to make sure the fan’s direction is correct and exhausting the hot air.
•         Lay the hot air collector down.
•         Put a good amount of silicone on the back of the solar panel and put it on one of the top corners.
•         Attach the solar panel to micro fan and let the silicone dry overnight.
 
How it works
•         The fan pushes hot air out and replaces it with cool air.
•         In effect the fan heats up a room faster.
•         The upper and lower holes will be ducted to the house.
•         If there is enough sun to make heat, then there is enough to make electricity for the fan. 

Step 7: The Next Step

The Next Step

•         Make more hot air collectors and mount them on the house to offset the heating bills. Possibly insulate the collector to reduce loss of heat through the side and back.

•         Reduce the fossil fuels we use. 

Testing
•         I placed the completed collector in a place where the sun shines for most of the day.
•         I placed a thermometer near the top hole of the collector.
•         I recorded readings every hour.
•         The reading of 53°C on the meter is the collector inside temperature as you can see the thermometer gauge inside.
 
•         On test day the maximum outside temperature for April 19, 2010 was 15°C.
•         The difference gave us a range of 20°C to 50.9°C free heat.
 
•         10:00 am   46°C / 114.8°F
•         11:00 am   58.5°C / 137.3°F
•         12:00 pm   63.1°C /145.58 °F
•         1:00 pm     65.9°C / 150.62°F
•         2:00 pm     62.4°C / 144.32°F
•         3:00 pm     54.3°C / 129.74°F
•         4:00 pm     35.0°C / 95°F

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    87 Discussions

    This is good idea to recondition any batteries. Thank you Gregory ! :)

    A few years back I came across a large piece of black tarp like material. One side is mildly glossy the other side is mostly flat black. I Put your standard Plastic window insulation over my south facing window and against that I put a piece of the tarp with the less glossy side facing outward. Even on mostly cloudy days I can feel the heat coming off of this piece of tarp. And that is just passive sun collection and radiant style heat coming off it to warm up one room. Best part of having it inside the house is that you get no heat loss from being exposed to the wind or possible extreme colds outside.
    I am planning to build a frame out of 2x4 that I have laying around and attaching 2 12volt computer fans hooked up to a solar panel I have. I will also be spray painting the sun facing side of the tarp with flat black paint to give it maximum UV absorption. But I expect the next design to be twice if not three times more efficient. If it does work I plan to build one for all of my south facing windows, and maybe even devise a way to put a couple on the west side of my home on the roof with insulated duct work to help heat my kitchen and basement.

    ?. Does the thermal windows in a house block some of the heat rays? I did an experiment with 2 pieces of aluminum painted flat black, put one outside in the sun and the other inside of a slider full sun through the glass, The outside one got almost to hot to touch, the inside one barely got warm.

    thanks Bill

    1 reply

    I don't know why you are having a problem with your indoor panel.
    A few years back I came across a large piece of black tarp like material. One side is mildly glossy the other side is mostly flat black. I Put your standard Plastic window insulation over my south facing window and against that I put a piece of the tarp with the less glossy side facing outward. Even on mostly cloudy days I can feel the heat coming off of this piece of tarp. And that is just passive sun collection and radiant style heat coming off it to warm up one room.
    Do you have a problem with airflow through your window, or anything obstructing the window that would cause it not to absorb all possible sunlight?

    ?. Does the thermal windows in a house block some of the heat rays? I did an experiment with 2 pieces of aluminum painted flat black, put one outside in the sun and the other inside of a slider full sun through the glass, The outside one got almost to hot to touch, the inside one barely got warm.

    thanks Bill

    Ok everybody is up in arms about the fan. I myself made a very cheap passive solar heater using a piece of card board painted flat black over the inside of my south facing window by leaving a 1 inch space at the bottom and a 2 inch space at the top. staples some plastic over the top opening to prevent the air from going backwards at night when it got cold but was able to push the hot air through the top around the bottom of the plastic when the air heated up during the day. Even though it was passive, (no fan what so ever) it did make a large improvement on how warn our living room stayed during the day an reduced the amount of wood that I had to burn. With this method in this instruct able, I would suggest something on the inside over the bottom hole that would work as a check valve to keep the cool air from coming in to the house through the bottom when the air outside cools and cools the air in the collector or even some type of one way check valve at the top, however with the duct on this bringing it into the house I would suggest on the bottom on the inside of the solar collector. It must be light enough where the air can move it out for it to draw but heavy enough not to allow the cool air to pass back through the hole going backwards. even with the fan there needs to be some kind of check valve to keep the cold air from coming in since you will not be using the fan on it when there is no heat in the collector. With the fan it could be a heavier type of material. Just an idea for you to expand on. Other than that I thought it was a vary good Idea an true using the fan it would be better to have it at the bottom to make the fan last longer, but I myself like the passive much better, imo. Keep up the great work. and don't let anyone knock you down with their comments it is all trial and error on the most part.

    I really like this and will implement it to offset my heating bill during winter ! Brilliant idea !!!

    1 reply

    The overall concept is great. I am using a 3" - 12 volt bilge fan and a 12 volt thermostat that is set for hi low temps. All of my power is from 2-10 watt solar panels and small gel battery. My solar controller/charger is from Harbor Freight. My heat tubes are 2 ft. pieces of aluminum duct and elbows. My glass is a used 32 x 60 inch aluminum window. If you mount the fan on the return air side, you do not have to worry about the high temps. If you have an existing central air unit you can hook this straight to the plenum and your inside thermostat will react to the supplemental hot air you are pumping into the house. These are not free, but cheap enough! I am about finished with this one. I will post pics and instructions as soon as I finish my installation.

    One mod I could suggest to this is a liquid circulator. Just attach some 1/4" or so copper tubing and paint it black too. That way you get the double benefit. Just pump the liquid into the house and to a radiator and a fan and presto-heato!

    Excellent advice on being an Eco recycler. Another place to ask is where you see a commercial building tenant improvement in progress. They often gut the interior including 10 year old obsolete lighting for the panel boxes and acoustic ceiling tiles that could be used inside the boxes for insulation.

    1 reply

    Thank you for your comments, When you think about it even poop is not waste, methane gas (cooking heating), fertilizer and even a source of solid fuel, Even in some places in the world they polish the floors with it. One mans trash can also change the world for the good.By the way here is an updated you tube video about solar hot air collector that I made. Enjoy

    http://www.youtube.com/watch?v=NZwdhjTWU0c

    Eco Steve

    I've heard that putting foil behind radiators reflects heat back into the house (rather than heating the walls). Has anyone considered lining the box with tin foil rather than using black paint?

    1 reply

    Thank you for the comment, although in this instructable I did not line the box with foil instead just painted black. But in this follow up You Tube video tutorial I did seal, install foil backed foam board and paint the surface flat black to absorb the sun. Enjoy

    http://www.youtube.com/watch?v=NZwdhjTWU0c

    Eco Steve

    i have seen these but this is easier than the others

    wOw   impressive     its shirley got me thinking.    
    would like to see photos of the finished installation ?  could boxes like these be constructed out of wood or is there an inherent advantage to metal ?

    2 replies

    https://www.instructables.com/id/Solar-Heater/

    From some of the discussion on that 'ible, it sounds as if *not* using metal may have some advantages.

    So even though metal construction might be slighly less efficient, the fact that ecosteve got these fixtures for free and is keeping them out of the landfill probably equals everything out in the end.