Why Air Sealing Matters: Your Home Could Be Losing Energy Through Small Gaps
When homeowners think about improving energy efficiency, insulation is often the first thing that comes to mind. But insulation is only part of the equation.
Your home can have plenty of insulation and still lose heated or cooled air through small gaps and openings throughout the building envelope.
That's where air sealing comes in.
What Is Air Sealing?
Air sealing is the process of identifying and sealing unwanted openings that allow air to move between your conditioned living space and areas such as the attic, basement, crawlspace, or outdoors.
Common air leakage points can include:
Plumbing and electrical penetrations
Gaps around ductwork
Recessed lighting
Attic hatches
Gaps around chimneys and flues
Openings around pipes and wires
Gaps between framing members
Areas around windows and doors
Some of these openings can be difficult to see from inside the living space, which is why a professional energy assessment can be helpful.
Why Does Air Leakage Matter?
Your home's heating and cooling system is designed to maintain a comfortable indoor temperature. When conditioned air escapes through unwanted openings, your system may need to run longer to maintain that temperature.
During the winter, warm indoor air can escape into colder areas of the home or outdoors. During the summer, hot outdoor air can enter through the same types of openings.
The result can be uncomfortable rooms, drafts, uneven temperatures, and increased demand on your heating and cooling equipment.
Insulation Doesn't Stop Air Movement
This is an important distinction.
Insulation is designed primarily to slow heat transfer. It does not necessarily stop air from moving through gaps in your home's building envelope.
For example, an attic may have a good layer of insulation but still contain openings around plumbing pipes, electrical wiring, or the attic hatch.
That's why simply adding more insulation isn't always the complete solution.
A properly insulated attic should also be evaluated for air leakage.
How Do You Know Where Your Home Is Leaking Air?
Some air leaks are obvious. Others aren't.
A professional energy assessment can help identify areas that may be contributing to unwanted air movement. One diagnostic tool commonly used during an assessment is a blower door test.
A blower door temporarily depressurizes the home so that air leakage can be measured and potential leakage areas can be identified.
The test can provide a useful baseline for understanding how leaky a home is and can help guide air-sealing recommendations.
Where Is Air Sealing Most Important?
Every home is different, but some areas commonly deserve attention.
Attic
The boundary between your living space and attic can contain numerous penetrations and gaps. Air sealing these areas before adding insulation can help improve the performance of the attic assembly.
Basement or Crawlspace
Gaps around pipes, wiring, rim joists, and other penetrations can allow outdoor air to enter the home.
Windows and Doors
Gaps around older or improperly sealed windows and doors can contribute to drafts. However, not every window problem
