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Dave Milliken of Horizon Residential Energy Services uses a special fan and door seal to find air leaks in a home owned by Michael Audet of Scarborough. When an energy audit is completed, the findings and recommendations for sealing leaks can help a homeowner set priorities to save the most fuel for the smallest investment.

enlarge Gordon Chibroski/Staff Photographer

Home energy auditor Dave Milliken inspects the attic of Michael Audet’s home for areas where warm air could be escaping. He said the attic has adequate insulation, but he noticed gaps around pipes and fixtures that could allow some air leaks.

enlarge Gordon Chibroski/Staff Photographer

Dave Milliken uses a digital camera to document his work and to give him a view of places he can’t see without a ladder. Here he examines a close-up shot to check for gaps in insulation.

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Click here to read stories in the "Fighting Back" series, participate in a poll and see how Maine manufacturers are coping.

Click here to learn how to save money by sealing air leaks and improving insulation.

Click here to download a PDF of energy efficiency tips and do-it-yourself projects for your Maine home.

FIGHTING BACK: SURVIVING HIGH-PRICED OIL

SUNDAY: Mainers are looking for ways to climb out from under the crushing cost of fuel.

TODAY: Families can save hundreds of dollars in heating oil charges this winter.

TUESDAY: Shoppers are cutting their grocery bills, despite the run-up in food prices.

WEDNESDAY: Drivers can use the pump a lot less often, with smart road strategies.

THURSDAY: People are making life changes that, in the years ahead, might transform the state.

MORE ONLINE

Home Energy Assistance Program and list of certified auditors

Sealing air leaks

Efficiency Maine

The typical Maine home could trim its oil heat bill by hundreds of dollars this winter, energy experts say, by plugging air leaks that make the entire building act like a chimney.

Four out of five Maine homes use oil or kerosene and are facing another winter of record prices. But much of this expensive heat will be lost through a basic process: Cold air that enters at unsealed foundations, loose windows and poorly installed dryer vents will be warmed, rise to the home's high points and exit through attic hatches, fan vents and other openings.

Proper air sealing can cut fuel consumption by 15 percent to 20 percent, according to the Maine State Housing Authority. In a home that burns 1,000 gallons of oil, 150 to 200 gallons – worth $660 to $880 these days – is simply drifting away into space.

But relatively few homes are taking full advantage of air sealing, according to experts. That's because many of the trouble spots are in attics, crawl spaces and cellars – places people tend to avoid. Beyond that, many residents are hard-pressed to identify and properly seal all the subtle nooks and crannies where air is entering and leaving their homes.

That became apparent last month in Helen Hemminger's home in Portland.

Back in the 1940s, the contractor who made built-in drawers in an upstairs bedroom of Hemminger's small, cape-style house created a nice space-saving feature.

In 2008, however, the design has unintended consequences. The kneewall behind the drawers is uninsulated, and the cold space sucks heated air through the drawer unit, all winter long.

Some of that air is being pulled from the cellar, which has an uninsulated foundation and rim joist and leaky casement windows.

The extent of the chimney effect became apparent recently when Dave Milliken, an auditor at Horizon Residential Energy Services LLC, switched on a blower that simulated a 25-mph breeze blowing on the house.

"That's like a wind tunnel," Milliken said, placing his hand by the drawer unit.

The velocity surprised Hemminger, who leaned over to feel the draft.

"That's not something I would have thought of," she said. "It's not near a window."

BALANCE INSULATION, VENTILATION

Air sealing requires specific materials and techniques to be effective. For instance: Hemminger stuck foam weatherstripping along several windowsills and a kitchen door frame, where she feels cold drafts. But she didn't use the right product to make a tight seal.

This sort of confusion is commonly seen by professionals such as Milliken. It illustrates the challenge of short-circuiting the chimney effect in older homes, which represent a large proportion of the housing stock in Maine.

Energy auditors recommend air sealing as part of a comprehensive strategy that includes proper insulation and ventilation. The right balance can cure other ills, such as ice dams and mold.

Milliken uses his training and sophisticated equipment, such as a blower that depressurizes the house, to ferret out air leaks. His fieldwork and a detailed report cost $295. This analysis can help a homeowner set priorities to save the most fuel for the smallest investment.

Energy audits are required by the state's newly expanded Home Energy Loan Program. The program currently offers loans for energy improvements at the below-market rate of 3.95 percent. But to get that rate, applicants must hire a certified energy auditor. And they must complete all recommended air sealing and insulation upgrades before they can borrow for a new heating system or windows.

Even without a formal energy audit, a handy homeowner can identify and fix some of the leading air leaks, said Tony Gill, who trains and certifies energy auditors at the state housing authority.

The first place to look: the space around your home's chimney, if it has one.

To meet fire codes, builders leave...