Solar Heat with Rock Box

Susan Bloomquist, Peak to Peak.  One of the puzzles of global climate changes is how to adapt. Without exception, we all use fossil fuels or carbon based heating units. We rely on these heating units for our very lives. Many Coloradans use fire as a source of heat. Mountain folks know how to chop wood and build a fire. Fire may be the only source of heat in storms with power outage.

How did the First Nation people stay warm over the long, cold winters here in Colorado? They burned wood for fire, just as we do today. Another strategy used was to build a small dugout with a fire pit and stones kept warm through the labor of fire building. Coming back from a long hunt for food, the forager would be able to enter the dugout and reclaim comfort for chilled limbs and organs. The hot rocks were the source of heating the body.

Fast forward to today. Some fire places have soap stone coverings, but seldom do we employ the use of hot rocks to comfort the body. With furnaces, one heats air or water, it would not be viable to heat rocks with this method. Fire is labor intensive and time consuming to maintain the heat at all times.  But would it not be nice to have a box of hot rocks which are always available to keep a room warm? If one were breeding fine animals, a box of hot rocks would keep the mother and babies warm, usually resulting in better outcomes.

This kind of technology is different from the latest electronics. People have used these simple technologies all through human history to improve their lives. One advantage we have in the 21st century is materials. Using Trex®, steel and a special black absorber plate coating, SunnyTherm® designer, Gary DuChateau, has developed a solar heat collector used to heat a rock box. The beauty of using a closed system solar air heater connected to a closed steel box filled with rocks and a baffle is there is no labor to maintain the heat in the rocks. No fire, yet hot rocks available at all times when the sun shines, and for many hours after the sun goes down. Spring months with the bright sun and cold temperatures are the hardest to bear because the eyes see warmth, but the temperature is frigid. These months the rock box would be most welcome to cold limbs and organs.

Solar Hot Air heat is developed using a black absorber plate to heat air inside the tightly closed space. A blower or fan is used to move this hot air to the desired location, inside a room or through a rock box. The rocks absorb the heat and the air is returned to the outside absorber plate area to be heated again and again. There is no fire danger in this system, because although air temperatures can reach 145° inside the vertically mounted collectors, this is not enough to start a fire. There are no pilot lights or ignition material of any kind. When the air reaches a certain temperature inside the collectors, if they are not fanned down, they expand slightly and release excess heat outside the building. This is a simple, durable system made of recycled hard plastic, steel and rocks. The fan is the only moving part.

When adapting to global climate change feels like a toasty warm rock box inside your house, barn or office, the process could have some unforeseen benefits.

BeeYond Gardens  PO Box 1281 Nederland, CO 80466  303-258-7851