Correction: The story incorrectly described John Bristol’s house as being in Bethesda. The house is in Chevy Chase, Md. This version has been updated.

John Bristol’s 4,500-square-foot, four-level Colonial in Chevy Chase, Md., would have been pricey to heat even without air leaks but the two rooms with wood-burning fireplaces were always cold in winter. He said he believed it was caused by air passing through the chimney flues.

“There just seemed to be a lot of downdraft. Those two rooms were always cold,” he said.

After last winter’s heating bills, Bristol had had enough. In early spring, he was ready to try to minimize air loss in the house. “I started searching around on the Internet and found chimney pillows,” he said. He purchased them for the two fireplaces and found that they were easy to install.

“I put the first pillow in the coldest basement family room that was drafty in February 2012, and the second pillow in the first-floor living room,” Bristol said.

The chimney pillow, also known as a fireplace plug or chimney balloon, is a large plastic bag that is inflated to block airflow through a chimney so that air neither escapes from nor enters the interior of the house. The plastic bag, which comes with an inflation tube, is usually installed by partially inflating the bag, placed inside the chimney, and then inflated to fit snugly. Homeowners are advised to leave the inflation tube hanging down into the fireplace so that they remember to deflate the bag and remove the device from the chimney before lighting a fire.

For an investment of about $55 per pillow, Bristol said he has seen a noticeable improvement — his energy bill dropped by $722 over seven months, or $103 a month. By Bristol’s calculations, he saved 14 to 30 percent ($623) from February to April and as much as 9 percent ($99) May through August.

“The average over these seven months [since installation] was 13 percent less consumption” than the previous year, he said.

Sweater weather is upon us, with Washington-area temperatures this week plunging into the 40s and 50s, a reminder that winter lurks just around the corner. Will your house be ready to weather the chill?

Now is the time to begin assessing the investments you may need to make to ensure that you’ll be warm this winter and experience lower energy costs over time.

“The average U.S. household will spend about $990 for winter heating costs this year,” said Allyson Schmutter, spokeswoman for the Alliance to Save Energy. “There’s an incentive to make changes that are easy and realistic,” she said. “There are many simple and energy-efficient fixes that help keep money in your pocketbook while keeping your house comfortable,” she added.

Sealing air leaks and improving insulation can save as much as 20 percent on heating bills, for example.

Homeowners don’t need to spend a ton of cash to make some very simple improvements, according to Mark Tyrol, owner of Massachusetts-based Battic Door Energy Conservation Products. The key is to find and seal off “overlooked openings,” according to Tyrol. The company’s two top-selling products cost less than $100: an attic stair cover ($99) and fireplace plugs ($54.95).

The company’s other popular products include attic fan seal kits ($29.50) and clothes dryer vent seals ($19.50).

Not all experts agree on some of the common-wisdom fixes.

“There’s a lot of miscommunication” about the efficiency of replacement windows and attic fans, said Troy Tanner, owner of the Home Energy Detective, a home energy audit company.

For example, “never install an attic fan,” said Tanner. “They cause all kinds of problems.” If you already have one in your house, Tanner believes you should “turn it off. That’s the best thing you can do,” he said.

Windows are another iffy investment, according to Tanner. About 14 percent of an average U.S. home exterior is windows. Thus, he said, replacing windows with more energy-efficient ones may not necessarily be the best place to start upgrading your home for energy efficiency. “You’re better off sealing the duct system and air sealing the house,” including all exterior walls, the foundation and the attic, said Tanner.

Here are some other tips on how you can winterize your home:

Seal ducts. Along with installing energy-efficient heating and cooling systems, homeowners can save as much as 20 percent by correctly sealing the air shafts between walls and floors that distribute air in those units, according to the Environmental Protection Agency. Sealing ducts, according to the EPA, can not only help homeowners heat their homes more evenly but also save them as much as $140 a year in energy costs.

Tanner said he sees a lot of clients with duct problems. “There’s usually a room they can’t keep hot or cold.” In most cases, he said, “it’s the air delivery system.” For his clients, “the number one concern is comfort,” said. “It’s usually about air movement in the house. The trick is to get the air where it’s supposed to go. In most cases, the duct system is inadequate as a result of original construction,” he said.

Replace air filters and clean your heating system, or have it professionally cleaned and inspected. Dirt and neglect are the main causes of system failure, according to the EPA. You don’t want to be one of the many calling the heating service company the first night a cold snap strains your furnace or heat pump.

Air seal your home. There are a number of companies that will provide energy assessments and identify leaks. Complete air sealing includes the entire outer shell of the structure, including the attic, the exterior walls and the foundation.

Perform an online energy assessment. At Energy Star (, you can enter totals of your previous year’s worth of energy bills to compare your expenses with those of similar homeowners.

Program the thermostat. Install or properly use a programmable thermostat. By adjusting settings when no one is home, you can save $100 a year, according to the EPA.

Check doors, windows and gutters. If any weatherstripping is loose, repair or replace it. Swap out summer window screens for solid panes. Thoroughly clean gutters, check or install leaf guards, and make sure the drainage spouts are tightly attached to the bottom of the gutter to direct melting snow away from the house.

Locate your snow shovel. Remember when you lent it to your neighbor after the last storm? Inspect it for wear to make sure it won’t break in the first snowstorm of the season. Don’t be the person racing to the hardware store only to find the shovels are sold out.

Check batteries. Make sure your flashlights are working and that you have extra batteries on hand in case of a winter power outage.

Get an energy evaluation. The nonprofit, Charlottesville-based Local Energy Alliance Program (LEAP) is among the firms that perform upgrades to homes in Arlington, Loudoun, Prince William and Fairfax counties. Upgrades — such as reinforcing air sealing around exterior walls and foundations — typically reduce energy use by 20 to 50 percent, according to the company.

If you live in Northern Virginia, you have until Sunday to enter a contest to win a free in-home assessment and one of three home energy makeovers worth as much as $10,000 in the Northern Virginia Home Energy Makeover Contest. The contest is sponsored by LEAP, the Dominion Foundation and Dominion Virginia Power. Their partners include local governments and financing institutions, such as Arlington County, Alexandria, Arlington Community Federal Credit Union and Commonwealth One Federal Credit Union.

To enter, you just need to fill out a home assessment at

Bristol said he didn’t stop with the chimney pillows in his 1994-built Colonial. He also affixed window sheeting — clear plastic — over his windows to minimize air loss from December to March last year.

“They’re nice windows, but they’re single-pane glass,” he said. He knew about the energy-saving benefits of the window sheeting, which provided significant savings at his previous home. “At my old house in Bethesda, it saved about 15 percent in BTUs,” he said.

Susan Straight is a freelance writer.