What does a solar cook know about heating and cooling a home? Well let me tell you! After reading volumes of ideas from other solar cooks on what is the best insulation that won’t off-gas nasty chemicals on the cooking food, I can tell you that the humble cardboard is still the hands down winner for the best cheap solution. Yes, there are some better insulation products, but they are costly by comparison.
I can also tell you from the experienced solar cooks that bright white is as and sometimes more effective at reflecting light than silver.
So let’s put this together. First you need to cut sturdy cardboard to fit over your south-facing windows. Then you choose to cover your cardboard with either white paint or fabric. I used fabric on my largest windows and baking parchment paper for my smaller windows. I only used 1/8 inch thick cardboard, but plan to make them thicker. I am guessing an inch thick is needed, but have not tested that out yet. How to test is to feel the inside-facing cardboard. If it is warm, than it is not thick enough. This is the same test for solar ovens. Warms sides indicate heat is escaping from the oven. For windows, warm cardboard means the window does not have enough insulation to block the insolation (solar radiation).
I realize this sounds like it will look tacky. I don’t think it does. From the outside, white looks like frosted privacy glass. From the inside, the cardboard needs something decorative. I have recessed windows. If I was ambitious and artsy, I would cover it with decorative fabric and a nice frame so you could not know I was covering a window, but I am not so ambitious with artsy stuff, sigh, so I have white. This window cover is only needed during Hemet’s blowtorch-hot season.
Lastly, if you happen to have weeping windows. I made that term up. I mean if your windows have condensation on them, then water proof the cardboard before covering it with fabric. The water proofing products are discussed in my post about cardboard swimming pools. Use shower curtain fabric if you need mildew resistant fabric.
Here is a homemade air cooler that uses water, tubing and a fan: http://offgridcamping.wordpress.com/2013/05/26/diy-air-conditioner.
The following are instructions for constructing a solar air heater: http://www.sciencebuddies.org/science-fair-projects/project_ideas/EnvEng_p028.shtml.
How effective is it? I don’t know, but I hope to talk my son into doing this project for science fair. Fortunately, the largest south-facing window on my home is in a barely seen room. Tolerating a strange and ugly window covering in this room won’t be a big problem.
Yes, of course, I have more resources, but no time to post them. This is yet another post in progress. By posting what I have now, I will be reminded later to come back and fill it up with the other cool, or should I say, “hot” links I have for this topic as I education myself toward off-griddle living. [all puns intended]