Cold and Drafty: A Town Topics Column
by Lasley Brahaney Architects
AIn winter, the chilly air is an unwelcome visitor to our cozy homes. Walking from room to room, we may suddenly feel a cold draft as if a window is open even though all are shut tight. One way to figure out where the air is getting in is to do a home energy audit.
Energy audits will help uncover problems that, when fixed, will certainly make you feel more comfortable and could save you energy and money. By identifying precisely where your house is losing energy and by sealing those areas, you could get great results. You may do a simple audit yourself, or hire a professional to conduct a more thorough audit using more sophisticated equipment.
If you decide to perform your own audit, start by walking through your house and making a list of the places where you feel air leaks. In addition to the window and exterior door frames, look at electrical outlets, switch plates, baseboards, fireplace dampers and attic hatches. Look for gaps around pipes and wires as well as your mailbox slot. In each location, if a leak exists, check to see if the caulking and weather stripping seem properly applied with no gaps or cracks.
Check your windows and doors. If you can rattle them, or see daylight around the frame, there is probably an air leak. If you have storm windows separate from your window assembly, check to see that the storms fit properly and are not cracked. Storm windows can be replaced, but by upgrading to an entirely new assembly using energy efficient windows, you'll probably get better results.
After your self-guided audit, you may decide to hire a professional like us to arrange for a more detailed analysis. An energy auditor will likely choose from a variety of techniques and equipment to determine the energy efficiency of your home. One common diagnostic procedure is a blower door test which measures the air tightness of your house. A blower door is a powerful fan that pulls air out of the house, lowering the air pressure inside. The higher outside air pressure then flows into the house through all the unsealed cracks and openings and is easily discovered by the auditor. The auditor, using a smoke pencil, can then figure out where and how much air is leaking.
Auditors will also use a thermal infrared camera (thermography) to identify hard-to-detect areas of air and energy leakage. By taking a snapshot or thermogram of a wall or ceiling, an auditor can reveal heat variations showing the relative effectiveness of insulation in the wall or roof construction. You will actually see a snapshot with big black areas showing missing insulation inside your walls! Aside from damaged or missing insulation, you might also see areas of improper caulking, incorrectly installed materials, gaps in construction framing, mold and water damage. Thermography is commonly used in conjunction with the blower door test because the blower door exaggerates air that leaks through defects in a building's shell.
Whether you decide to go it alone or hire a professional, a home energy audit is an effective first step toward creating a more comfortable, energy efficient home.