o date suggests mold spores in indoor air can cause asthma symptoms, respiratory infections, and upper respiratory problems among susceptible persons.9
Critics say problems of poor workmanship in state weatherization programs over the past year are often the result of the programs’ hiring of large numbers of new contractors, not all of whom are properly trained or supervised. In Illinois, for example, the weatherization agency’s pool of contractors grew from 18 to 60 companies to accommodate the increase in production resulting from the infusion of ARRA money.5 In a memorandum to the Assistant Secretary of Energy Efficiency and Renewable Energy, DOE inspector general Gregory Friedman stated, “The weatherization contractor and local level inspection deficiencies, in our opinion, raise concerns regarding the adequacy of training and adherence to standards designed to ensure quality workmanship.”10
Problems with home energy retrofits are not limited to fly-by-night contractors. Even experienced contractors can be challenged when trying to deliver a product that is at once energy efficient and healthy. Houses are complex systems. The shell (walls, floors, ceiling), HVAC system, and ductwork all interact with each other—change one, and you may inadvertently affect another.
Tightening houses—that is, reducing the amount of outside air being pulled into the living space and heated or cooled air leaking out—is one of the principal goals of weatherization. However, it is important not to make a building too tight. The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) publishes a standard that lists recommended levels of fresh-air ventilation for different types of buildings or rooms within buildings, taking into account the size of the space, number of occupants, and use of the space.11 These levels reflect optimal energy usage, comfort, and health and should be followed by contractors anytime an extensive retrofit of a building is undertaken.
Tightening a building to the point where it actually reduces energy consumption is relatively easy in new construction; it is more difficult in an existing building because sources of air infiltration may be difficult to find and access. Measures such as adding storm windows and weatherstripping doors may improve comfort, but experts say they have a minimal effect on energy bills. “Air escapes from the top of a building, not the sides,” says Arnie Katz, senior building science consultant with Advanced Energy Corporation, a North Carolina–based energy-efficiency services firm. “If you just tighten the sides, all you are doing is creating a more efficient cylinder.”
Katz says the first priority in tightening a building should be to seal leaks in the top; the second priority is sealing the bottom. Air, he explains, typically leaks from the home through gaps around wiring, plumbing, ceiling lights, vents, and fans.
These gaps are often difficult to access, and workers trying to reach them may find themselves facedown in fiberglass insulation, so it is important they wear proper clothing and face masks when doing this work. The Occupational Safety and Health Administration (OSHA) advises that fibers freed from insulation can cause, skin, eye, and respiratory irritation, and requires that employers provide workers with proper respiratory protection when they are blowing fiberglass insulation into an attic.12
Assuming one can actually seal these leaks, the other challenge in tightening homes is to do so without compromising the occupants’ health. This is especially a concern for buildings with indoor combustion appliances such as oil, gas, or propane furnaces and water heaters, which can produce CO. Katz warns, “Anything you do to make a home tighter has the potential for causing backdrafting13 of these appliances, because you are changing the air pressure relationships inside the house. That’s why it’s so important to hire someone who knows what they’re doing.”
Trapping of radon is another potential result of overtightening a home. This radioactive gas found in s