A new product on the market could make waves in Cayman if homeowner Catherine Muller-Henning has anything to say about it.
The George Town Hospital nurse and energy-efficiency advocate is eager to spread the word about the Corwin Heet Bloc and the impact installing it in her new home has had on her energy bills.
The system has Mrs. Muller-Henning all smiles as she recounts a simple solution to reducing the amount of energy used to cool her home.
‘I heard about this insulation system and my husband and I decided to install it in the new home we were building,’ she says.
‘What we discovered was that we were able to cut our energy use by about 45 per cent.’
Unlike fans and blowers, the Heet Bloc does not use any energy and requires no maintenance. Installed just underneath a home’s roof, the Corwin Heet Block provides a radiant heat barrier that uses simple physics to vent hot air out of a home’s attic.
As air heats up, it wants to rise. Inside an unventilated attic, however, it can’t.
‘In hot climates or in the summer, the sun regularly heats an attic to temperatures in excess of 140°F,’ says the system’s inventor, Tom Corwin.
‘Even homeowners with adequate home insulation feel the effects of the heat absorbed from the attic into the living space by elevated temperatures in the living space below, and most significantly, in increased cooling costs.’
The Heet Bloc system creates a one-inch airspace between the roof and a sheet of foam board insulation which has a reflective surface on the roof side. It not only prevents heated air from traveling into a home’s attic space, it also uses simple physics to keep cooler air circulating in the attic space.
The natural forces of convection move air from a home’s soffit, a vent that draws air into the attic from under the eaves, to what’s called a ridge vent, located at the roof’s peak.
A second, shorter air channel on the other side of the foam board also begins in the soffit, but ends above the attic insulation to draw ambient air into the main attic space.
No matter how hot it gets, the system keeps working. In fact, as the temperature in the channel created by the Heet Bloc system increases, so does the rate of air flow. The ventilation also prevents the remaining attic space from attaining the same high temperatures.
‘This decreases the temperature differential between the attic and the living space and the amount of heat that is absorbed into the living space,’ says Mr. Corwin. ‘Translating that into cooling considerations, that means the amount of energy consumed to cool the home decreases.’
Another appeal of the system’s ventilation properties, in particular for homeowners concerned about good health in a humid climate such as Cayman’s, is that it greatly reduces mold and mildew formation in stagnant air.
However grand the claims, Mrs. Muller-Henning was not about to take Mr. Corwin’s word on the effectiveness of the system – she wanted proof.
‘I am one of those people who enjoys research. So I did a voluntary research project on my home using remote heat sensors hooked up to a central reader, which I monitored over a year,’ said Mrs. Muller-Henning.
‘The ventilation this system creates is enough to keep the actual attic temperature four degrees cooler than the outside temperature. Even my air-conditioning specialist says that we just might have the coolest attic in Cayman.’
All of the system’ components are available on-Island, ready to be installed by a trained contractor, at a cost of around $1.50 to $2 a square foot. For a typical home, that translates into about $2,000, installed.