How to Seal Your Home to Save on Heating and Cooling

There are several ways to cut back on your home heating and cooling costs, including switching to a smart thermostat, upgrading your HVAC equipment and implementing passive heating and cooling elements into your home design. But one of the best ways for most homeowners to lower their HVAC bills is to eliminate air leaks and seal their home envelope.

"Home envelope" is a term used primarily by architects, home builders and HVAC technicians, but more homeowners are familiarizing themselves with the concept as they learn about the energy costs of air leaks. The envelope of a home or building is the barrier separating the outside air from the inside air; walls, roofs, insulation, windows and doors are all major components of the home envelope.

Sealing and insulating your home can consist of dozens of steps, many of which may be quite simple and inexpensive, like filling cracks with caulking compound. And these little tasks can add up to make a big difference, because more drastic measures like replacing your HVAC equipment or modifying your home design can still be undermined by something as simple as drafty windows and doors.

Don't Work Hard, Work Smart: Schedule a Home Energy Audit

You can certainly go the DIY route to seal and insulate your home, but this involves a degree of guesswork. While caulking cracks, replacing weather stripping and adding insulation in your attic can't hurt, they might not be the most important solutions for your specific home. Sealing your home the smart way begins with identifying the weak spots in your home envelope.

Thanks to modern methods, you can pinpoint these vulnerabilities with a service called a home energy audit. In a home energy audit, trained professionals use specialized equipment to detect and measure air leaks that are invisible to the naked eye.

One common energy audit technique is the "blower door" test, in which an exterior door is sealed with a panel that has a powerful fan built into it. The fan sucks air out of a home, which pulls strong streams of air through gaps, cracks and other drafty areas. This allows the auditors to zero in on air leaks and measure the overall tightness of the home envelope.

Auditors may also use infrared heat mapping technology to see where hot and cold air is flowing through the home. This can be an effective way of spotting thermal leaks that don't "feel" drafty, such as leaks around recessed ceiling lights.

A thorough home energy audit should conclude with a detailed, data-based overview of the home's energy efficiency, as well as specific recommendations for improving performance. Many homeowners like to schedule a second home energy audit after making improvements to verify that their home is more efficient than before.

Home energy audits often cost a few hundred dollars, so it pays to call around for price quotes if you're thinking about scheduling one. But it's also worthwhile to check with your local government or energy utilities to see if they offer any free or reduced rate energy auditing services. Every home that reduces its energy consumption helps to relieve pressure on the energy grid and mitigate greenhouse gas emissions, so many cities and energy utilities are expanding their efforts to help homeowners access these services.

Eliminating Air Leaks Throughout Your Home

If you're not ready to arrange a professional home energy audit, or if you've already done one and want to start making improvements, there are several leak-sealing steps you can take on your own. Here are some of the most effective ways to shore up your home envelope:

• Find and seal drafts. Sometimes this is easier said than done, but there are some simple methods of draft detection. Turn off your HVAC system completely, preferably on a windy day, and examine the exterior walls of every room. Use your hand to feel for the flow of air around windows, doors and visible cracks. You can also use a candle or a handheld draft detector, which emits a smooth stream of odorless smoke, to detect air movement. When you find drafts, seal them using caulking compound for fine cracks and spray foam insulation for larger gaps.
• Inspect and replace your weather stripping as needed. The weather stripping around your doors and windows should be springy and create a tight seal. If it's cracked, brittle, torn or otherwise damaged, it should be removed and replaced. DIY weather stripping repair kits are available at most hardware stores.
• Inspect and upgrade your attic insulation as needed. Poor attic insulation can let your furnace's heat escape quickly in the winter, and allow superheated attic air to emanate into your home in the summer. Measure the depth of the insulation on your attic floor and compare it to the Department of Energy's recommendations, which vary by climate zone.
• If you have a fireplace, inspect the damper. A loose fitting damper can be a major vulnerability in your home envelope, not to mention a potential hazard when operating the fireplace. If you have doubts about your ability to replace the damper yourself, hire a professional – this is one job you'll want done just right.
• Ensure that the attic door closes tightly. Sometimes attic doors can warp or sag, allowing your HVAC-treated air to escape and untreated air to infiltrate your living spaces. A warped attic hatch may need to be replaced, but a sagging hatch can often be fixed by tightening or replacing the tension springs.
• Install foam gaskets behind light switches and outlet covers. This is especially important for switches and outlets that feel drafty. These inexpensive gaskets are easy to install – just remove the cover plate, put the gasket in place, and replace the cover.
• Upgrade inefficient doors and windows. This isn't a DIY project, and it's usually not a cheap one, either. But if you have thin exterior doors and single-pane windows, you're losing energy through them. Arrange a consultation and get a price quote from a reputable installer so you can budget for this worthwhile upgrade.

You can find more tips for taking care of your home in our Learning Center.