Hold on to your home fuel dollars by plugging their escape routes

Charles Wing likes to tell how he bought a turn-of-the-century farmhouse a few years back and then got his oil-delivery man to pay for all the alterations that would make it more energy efficient. The system worked so well that not only did the oil man pay off the bank loan but gave Mr. Wing an additional $500 a year to spend just as as he wished. This is how it happened: Wing, an author and researcher on energy-efficient home construction, borrowed $4,000 (repayable at $1,000 a year) to tighten up, insulate, and modify the interior of the rambling old building. In so doing he was able to cut the annual $3,000 heating bill in half. As he was on a monthly fuel payment plan, his fuel dealer rebated the $1,500 he didn't spend at the end of the year, which was $500 more than he owed the bank for the same period.

To be more accurate, it was the savings in unused oil rather than the oil dealer himself that paid off the construction loan in such handsome fashion. But Wing tells the story this way to press home the remarkable dollars-and-cents value of investments in energy efficiency.

Admittedly, home heating costs have dropped in recent years, but bank interest rates have fallen as well so that energy-efficiency alterations remain one of the best investments (currently about 25 percent) the homeowner can make.

Rather than think in terms of ``payback time,'' the number of years before the savings equals the amount of money spent on the project, the Wing message is to calculate the interest earned on the investment.

The best way for any homeowner to begin upgrading the thermal efficiency of the house is to get a walk-through energy audit from the local utility. Most utilities offer this service for a very modest fee or know of an organization that does.

In these walk-through audits the trained observer simply walks through the home, pointing out the obvious and not so obvious areas where the home is leaking heat. It's a hand-holding service that has proved far more effective than the computer-run models that were initially highly touted. A rough estimate of the savings relative to the cost of work involved is available at these audits.

Wing's advice to the homeowner wishing to plug as many heat leaks as possible is to remember that in winter warm indoor air travels through the house like smoke going up a chimney. It rises, passing through every hole, crack, or crevice, before exiting out through the roof. As it does this it draws cold air in at the basement level. So a prime rule is to first check out the basement and the attic, where minor repairs and changes can often produce large savings.

Basement: Repair cracks and holes in foundation walls. Check cellar windows for tightness, adding weatherstripping and new fasteners if necessary. Replace broken or cracked glass and caulk around the inside of the windows. Add storm windows or a sheet of clear plastic to all single-pane windows. Check caulking wherever electric cables or water pipes enter or exit a home.

Insulate cellar walls. Some 20 percent of a home's heat is lost through the uninsulated walls of a cellar. This percentage can go higher if the cellar walls protrude more than two feet above the ground. Don't be afraid to insulate the entire wall. Statements that insulated cellar walls have cracked from frost pressure in very cold climates have not stood up under scrutiny.

Attic: Check for air leaks around chimneys and flues and where ducts, electrical wiring, or plumbing descends into the living area. Plug the leaks with a non-flammable material. If necessary add insulation to the recommended depth for your region.

Ceilings: By most calculations at least a dozen hidden holes exist in the ceilings of every home. Check in closets where pipes and wiring are often hidden and behind recessed light fixtures.

Walls: Insulation, either cellulose, rock wool, or fiberglass, can be blown into the cavities of all uninsulated walls. This not only increases the R value (resistance to heat transfer) through the walls but dramatically cuts down on air leaks and drafts within the structure.

Condensation, where warm moist interior air diffuses through the walls, then cools down, releasing its moisture within the insulation, is not the problem that was once feared. All cracks or joints, however, particularly around windows and doors, should be thoroughly caulked on the inside to prevent warm air from leaking into the walls. On the other hand, windows should not be caulked on the outside, so that any moisture that might migrate into the walls in winter will be able to evaporate away in summer.

Interior walls sometimes funnel vast amounts of warm interior air up into the attic. These can be checked and blocked off in the attic itself. Another option is to have insulation blown into these interior walls. This is particularly beneficial in those walls that carry the hot water pipes to the upstairs bathroom. A much quieter house is another benefit from this interior insulating, though, if quietness is a prime objective, use cellulose or rock wool rather than fiberglass.