Do you remember the energy crisis? The energy industry certainly does. Consumers changed overnight from energy wastrels to energy misers, and 20 years later the building industry and the people who make heating and cooling equipment are still coming up with ways to cut energy costs.
Over the years it's become clear the two best solutions are interlocking: houses have to be made more energy-tight, so heated or cooled air doesn't escape; and once that's done, heating and cooling equipment should be made smaller, to meet reduced energy demands.
New construction benefits the most from such maximum-energy-conservation efforts, but if you're doing a significant amount of construction in an older house, some of the techniques can be applied there, too.
John Spears, of Energy Conservation Management, a Baltimore energy consulting firm, contends that if you build a house his way, you can reduce energy use by as much as 70 percent with no additional cost in building materials or equipment.
The goal, he says, is to "reduce the energy requirement to nothing, so you can heat with a candle and cool with an ice cube."
Mr. Spears bases his energy savings on a "typical" dwelling, two stories, 2,400 square feet, with a heat pump, double-pane windows and energy costs of $1,900 a year.
Among the techniques for reducing that figure: increasing insulation to R-19 (a measure of heat flow; higher numbers mean less heat escapes) in walls and R-40 in ceilings; reducing cold-air infiltration (in winter) by 50 percent; and using a gas-fired "combo" device to heat the house and provide hot water.
In his own house in Montgomery County, Mr. Spears specified insulation of R-40 in both walls and ceilings, and used South-facing windows that capture the free heat in winter (with an overhang to shade them in summer).
Before any insulation was installed in stud wall cavities of the house, all gaps and places where surfaces meet were caulked and sealed. (This is a technique that rehabbers could employ; it's an inexpensive, effective way to stop air infiltration.) Mr. Spears uses a new form of blown-in insulation -- cellulose mixed with glue, so it sticks to studs and wall surfaces. It's made of recycled paper and is non-toxic and environmentally friendly.
To help reduce the energy demand for air-conditioning, Mr. Spears took advantage of a natural feature: Air for the cooling system passes across the pipe that brings water from the well -- at a constant 50 degrees.
Obviously, not all these techniques and devices will work for every house. But there's enough going on in the energy-management field that no one should undertake any fairly major energy-systems work without checking out the latest information. Contractors, builders, energy consultants and your local utility are good places to start the research.
However, before you rush out and buy any energy-saving system or device, there are two things you should think about.
The first is payback: Will the unit really save you money, or is the initial expense greater than the savings you will realize during the time you use it?
The second thing to consider is pollution -- indoor pollution. Houses breathe for the same reason people do: to get rid of excess moisture and harmful gases.
As you seal up your house to prevent heat loss, you are also sealing in moisture and vapors. That can cause moisture problems -- leaks, condensation -- and may even cause health problems, especially if someone in your family has allergies or is sensitive to vapors from furniture, carpets or building materials.
Another problem is radon, an invisible, odorless radioactive gas that, in studies involving heavy exposure over time, is linked to lung cancer. You should know before you start sealing up the house if you have a radon problem; if you do, you need professional assistance to abate it.
Some indoor air problems have extremely simple solutions, however: exterior-exhaust fans in strategic locations, such as over the stove and in the bathroom, don't cost much and can keep any changes in your house's respiration from becoming a problem.
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