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| Warmer: James Turner invested $17,000 to boost the energy efficiency of his New Hampshire home, money he expects to recoup
in five years. mark thomson |
This cold house? Not anymore.
How a frontal assault on insulation and air leaks cut a homeowner's heating costs in half.
from the March 24, 2008 edition
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"We're going to look into all the areas of the home," Ramage explained, "and many of them are hidden areas. It could be the attic, it could be 'knee walls,' which are hidden areas in a Cape. We'll check the framing of the walls, see if there's some open chaseways," wall cavities used for ducts, plumbing, or wiring.
Ramage points to other areas worth investigating: heating-system ratings, basement-wall insulation – and the insulation on the heating and hot-water systems themselves.
Auditors can use computer modeling to test possible changes and estimate costs and pay-back periods.
A critical part of an energy audit for an older house is a blower-door test. This involves installing a door frame with a high-powered fan in one door of the house, and closing all the other doors and windows. By measuring how much air still can be drawn out of the house, it gives a picture of how leaky the house is and provides a baseline to measure improvements. Our initial blower-door test was a disaster: The auditor couldn't even get the house tight enough to get a read on the meter.
It turned out that four of our fireplaces that we weren't using only had pink insulation stuffed up the chimneys. Part of our budget went to placing sheet-metal barriers in the chimneys.
But our major expense was having polyurethane "hard cell" insulation blown onto the ceiling of our basement and the floor of our attic. This stuff looks like Styrofoam, but it's hard enough to walk on. It not only provides R-8 of insulation value per inch, but it also acts as a vapor barrier. It sealed off any drafts. Ramage recommends insulating the walls of the basement instead of the ceiling, since it will keep your basement warm as well, which reduces heating loss in the pipes or ductwork in the basement. It also helps waterproof basement walls.
Finding the right company to handle your energy audit can be critical. Mr. Gray of the Office of Energy Planning suggests that homeowners check with local or state associations of professionals – home builders, energy professionals – or find contractors working within established utility-efficiency programs. Such groups usually have member standards and often provide training.
"If you think you've found someone, ask them if they own a blower door, an essential tool for quality air sealing," says Gray. "[Can they] install dense-pack insulation? Do they understand the principles of 'house as a system'? Are they familiar with the International Energy Conservation Code of 2006?"
We still don't have a perfect house. We managed to get our blower-door test down to about 5,000 cubic feet per minute of airflow (a tight house would have 1,000-2,000 CFM), and cut our monthly fuel-oil usage just about in half. Our dining room, which once hovered at a dismal 60 degrees on a cold day, now holds at 68. The work wasn't cheap, around $17,000, all told. But with fuel oil in New Hampshire running more than $3 a gallon, saving 1,000 gallons a winter will pay that back in five or six years – and reduce our carbon footprint, too.
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