Hangar Heating – Passive Solar Up To 55 Degrees

Hangar Passive Solar HeatingWhile at the EAA’s AirVenture in Oshkosh, WI, I had the opportunity to meet a recently retired American Airlines 777 captain by the name of Bob Moreland.  During our brief introduction, I learned of a unique hangar project he recently completed at the Rockford International Airport (KRFD) in northern Illinois. He was able to share a little information with me at that time but invited me to visit the complex when our schedules allowed. We finally found a common date in late October.  The colder temperatures set the stage for what I was about to witness.

It was a chilly, crisp, and sunny Saturday morning with the winds of change whirling about. Bob met me at the security gate at the northeast corner of the field and led me through a set of stereotypical hangars for GA aircraft. I realized we had approached his new set of hangars when I saw an item that seemed “out-of-place” at an airport – solar collectors.

I was welcomed into his hangar and quickly noticed how airtight the building felt.  We walked up Thousands of feet of Pex tubing installed under hangar's concrete slabthe stairs to the meeting area that overlooks his Cessna 180. With all smiles, Bob started to tell me about his project which began with a simple phrase, “free to fifty-five.”  With further explanation, I learned exactly what he meant. Each of his three complexes (with eight hangars in each) cost virtually nothing to heat up to 55 degrees Fahrenheit.  Through the use of a series of solar collectors installed on the roof, a device to keep the fluid circulating, a supplemental heat source (when temperatures above 55 degrees is needed), a few thousand feet of PEX tubing embedded in the concrete slab and a tremendous amount of insulation, he was able to achieve this feat.

One must note that solar collectors have been used to pre-heat water for home and business use for quite some time. Homes in tropical areas such as Hawaii have them. For that matter, even my uncle’s farm in Wausau, WI, has one.  What makes this application so interesting in the world of aircraft hangars is that this is the first time I’ve seen it done commercially for use in an aircraft hangar.

After nearly an hour of talking about the system and its benefits, Bob took me on a tour to glycol temperatures before and after loopwitness his proprietary design in action. With no visible moving parts, there really isn’t much to report as most of the system is “passive” in nature. The most fascinating parts of the design are the two thermometers measuring the temperature of the fluid. The first thermometer is just downstream from the solar collectors and it measured a scalding 110 degrees Fahrenheit. The second thermometer was positioned after several thousand feet of PEX. Its temperature measured an amazing 60 degrees.

The heating system is really just one-half of the story. The other half of the story is the building’s insulation and its ability to retain the heat. Every effort was made to reduce heat loss. The walls of these hangars are very thick with insulation rated at R-30. The ceiling insulation is rated at an incredible, R-50. The actual construction materials are wood to help reduce thermal transfer through steal beams. Interior walls are “finished” along with a complete vapor barrier system to aid in the prevention of condensation that can lead to breakdown of insulation and structural corrosion.

Even the concrete slab is insulated. Prior to pouring the concrete, a bed of foam insulation was put in place to form a barrier between the concrete and the soil. This action minimizes heat transfer into the ground and maximizes the efficiencies of the radiant floor heat.

The ultra-efficient heating and insulating properties of these hangars are something to behold. And after a review of the financial and environmental benefits, the evidence was simply mind-boggling. Utility costs of each complex are shared among the eight hangar occupants. One meter instead of eight, efficient lighting fixtures, supplemental heating (when temperatures above 55 degrees are required), water, insurance and association fees add up to only $125 per month per hangar occupant.

The environmental savings are staggering. There is minimal environmental impact in achieving indoor air temperatures to a base-line temperature of 55 degrees as effectively no fossil fuels are consumed to generate that heat. There is some consumption of electricity to transfer the heat from the solar collector to the floor but that energy is the equivalent of using a 100 Watt light bulb. Virtually no heating cost, no fossil fuels consumed and no CO2 emissions.

It’s a win-win-win for all parties involved.

If you want to learn more about the hangars, you can contact Bob at 815-979-1977 or email him directly at ilgobbler@aol.com. Or, if you are ever in the vicinity of KRFD, just land there and taxi to the northeast ramp and look for the roof-top “solar collectors.”