solar air heater

solar air heater

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Oil is over $100 a barrel and the sun is still free. Despite the efforts of the politico-industrial complex to ensure we only buy our over-priced energy from approved sources, economic pressure from individual homeowners will force a move to "free" sources of energy.

The issue to date with most solar heating implementations is that the capital cost to redirect all those free photons into your home required payback periods of 10, 15, or 30 years. Only the most pioneering of families are willing to bet on a 30-year payback with technology that is improving every five days.

Transpiration solar air heaters can lower the payback period to the point where people will drive their pickups to the home supply store in the morning and start saving money by the afternoon-on a clear day you can see the future and the economics are pretty clear.

Fuel oil delivers about 139,000 BTU's per gallon at $2.95 a gallon; with prices rising fast. One BTU is enough heat to raise the temperature of a pound of water by 1 degree in one hour. An average sized house in the Midwest needs around 80 million BTU's to keep the occupants comfortable through the winter. Those 80 million BTU's come from burning 575 gallons of fuel oil at a cost of $1,697. That's your money going up in smoke. The heating season is about six months so let's assume you'll need 18,000 BTU's an hour as an average (the peak load would be much higher of course).

The sun provides around 450 BTU per hour per shiny square foot. Assuming 50% efficiency in the solar collector you would capture 225 BTU/ft2/hr or 1,800 BTU/ft2/day. The most economical application for solar energy is baseline heating-provide a slow and steady improvement by raising cool air to lukewarm air, burn the oil only to fight off the arctic blasts.

So, let's save some money.

Transpiration solar collectors provide low temperature air (80-110 degrees F) by pulling in fresh outside air and heating it on the way into your home. These collectors are simple sheets of metal or black plastic covered with small ventilation holes; this is not high tech it's just fabulous tech. The collector heats up in the sun, cold air circulates through and soaks up that heat, delivering clean energy to your living room. By the way, you're drawing in fresh outside air. These modern, air-tight homes are killing all of us. Has no one noticed that the incidence of toxic mold has gone up 3000 percent since "air-tight" homes started being built? They should be called disease-in-a-box homes; but I digress.

Transpiration collectors are extremely cheap because they are designed to run at low temperatures and require no glass covers and no insulation. They circulate air, not water, so they have no freezing problems and little maintenance. You can use your existing furnace ductwork and just pipe warm air into the house or use it to pump heat into the basement; which lowers the cost of keeping the entire house warm and operates as a giant solar storage repository at nearly zero incremental cost.

100 square feet of transpiration solar collectors would deliver 180,000 BTU's per day or 32,400,000 BTU's over the six-month heating season. That would eliminate 233 gallons of fuel oil and throw $687 dollars back into your mad money jar to do something mad with-Vegas anybody? These systems are cheap and simple so they should last 20 years. Now you've got $13,740 in your mad money jar-can you say, High Roller, baby?

That savings assumes fuel oil is going to stay $2.95 a gallon for the next 20 years. Let's be realistic, fuel oil is going to be more expensive than a college education in 20 years. Our kids are all going to work for Saudi Princes, shoveling their gold coins around, and we're going to be thankful when we can turn the thermostat up to 45 degrees and thaw out the toilets.

Start checking it out. If you can't find 100 square feet of transpiration solar collectors for less than $687 dollars I'll send you free plans and loan you my staple gun (just kidding about the staple gun go buy one with your Vegas winnings).

Copyright 2007, Lotus Pond Media

Steven C. Grant is the Director, Business Development for Lotus Pond Media and the co-author of two children's books about pygmy goats: Meet the Goat Kids and The Goat Kids Explore the Woods. You can read more stories about the goat kids at http://www.goatkids.net, enjoy family photographs, purchase goat kids memorabilia, and sign up for the Pygmy Talk forum. I got interested in solar power because I'd like to keep my goats from freezing in the winter without spending a fortune to do it. They're lovable, but not that lovable. So I'm playing with a very low tech, home-grown version of a transpiration space heater made out of drainage pipe. On a clear day, 10 feet of pipe heats fresh air over 50 degrees; happy, happy goats.

Active Solar Air Heater