The sun knocks at your door all winter. It peeks in your windows, and asks to come in. So rather than pay PECO to keep you warm, a simple $30 solar heat box will pour 80 degree air through south- or west-facing glass on freezing days. Sunlight zips through plexiglass at 600 million miles an hour, slams into the box's black base, gets trapped and multiplies. Heat then rises into your house through the top vent.
This powerful tool was invented in 1881 but forgotten while fossil fuels reigned. It's cheap, creates jobs for neighbors, recycles building materials, keeps money in your pocket, cools global warming.
Fancy solar boxes cost over $1,000. They sit on fancy roofs. Your solar box is made of scrap lumber, beer cans, foam board, flat black paint or black poly felt, caulk or silicon adhesive. It's mounted below a windowsill. There are endless styles. Hundreds of Philadelphians experimenting will invent models best fitting this climate. Thousands of youth will be employed, and some will own businesses. Here are several internet testimonials:
* "My dad's family lived in Johnstown, PA at the turn of the 20th century and the black boxes they built and put into the windows kept the house so warm the upstairs windows had to be raised. Just fifteen years ago my dad built one box for their dining room window to show my mother free heat could be obtained. After a month my mother had him take out the box for it made the whole floor too hot. Solar heating does work." NOTE: heat can be easily regulated.
* "I made a solar heater for the inside of my window and it effectively heats my room on any sunny day."
* "We find that the unit is helpful on sunny days in the winter, especially once we get to February and March. On such days the heater boosts the temperature in that room by an estimated 10-15 degrees."
* "I have a solar heat box. In the spring and fall when it's too warm for a constant fire this thing kicks on and takes the chill off in the morning."
Philadelphia enjoys 160 sunny days yearly. Many of our 93 cloudy days will generate solar heat, too: "This solar box will even come on sometimes with a cloudy overcast that we often get in the snowy season. The box I have is 3ft high and 6ft long. All of my neighbors have had their furnaces running now for three weeks and mine has only kicked on one day that was cold and rainy."
Some Philadelphians have built these recently. Says Eric Hontz, "The temperatures measured so far [in November] have been around 92 degrees in a 68 degree room. My windows face west, so I don't get a long duration of sunlight." Afshin Khaigobody's model was installed by Dan Wolk, who says "I set the heater up outside Mishkan Shalom' buuilding, last Sunday, in full sun, facing southwest, and put a thermometer at the outlet. "At midday, with the inlet [outdoor] air at about 45 degrees, the outlet [indoor] temp was 80 degrees."
You can become a solar heater expert by Googling or YouTubing "SOLAR AIR HEATER," or "SOLAR BOX HEATER," or "HEAT GRABBER." Following are a few of my favorite sites. --Paul Glover
Mother Earth News
Make a Simple Solar Air Heater
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Rules Of Thumb For Solar Air Collectors
This graph shows the losses from collector to outlet:
