Understanding Air Leakage in Your Home

You may already know where some air leakage occurs in your home, such as through a drafty window, but to properly air seal your home, you’ll need to find the less obvious gaps. Detecting these air leaks is crucial for maintaining comfort and energy efficiency.

The Blower Door Test

For a thorough and accurate measurement of air leakage in your home, hire a qualified technician to conduct an energy assessment, particularly a blower door test. This test depressurizes your home, revealing the location of many leaks and helping determine areas that need more insulation. A blower door test is essential because it quantifies the amount of air leakage through your building envelope. It involves installing a calibrated fan in an exterior door while sealing all other openings. As the fan pulls air out of the house, the resulting pressure difference allows outside air to flow in through unsealed cracks and openings.

Visual Inspection Techniques

Without a blower door test, there are several ways to find some air leaks yourself:

• Exterior Inspection: Check all areas where different building materials meet, including:
  • Exterior corners
  • Outdoor water faucets
  • Where siding meets chimneys
  • Foundation edges with exterior brick or siding
• Interior Inspection: Look around common leak sites for cracks and gaps:
  • Electrical outlets and switch plates
  • Door and window frames
  • Baseboards and weather stripping
  • Attic hatches and fireplace dampers
  • Vents, fans, and cable lines

Inspect windows and doors for movement; if you can rattle them, they may be leaking. Visible daylight around frames indicates leaks that can often be sealed with caulking or weather stripping. If replacing old windows or doors is too costly, consider low-cost plastic sheets as a temporary solution.

Building Pressurization Test

If you’re having difficulty locating leaks, consider conducting a basic building pressurization test:

1. Turn off all combustion appliances (e.g., gas furnaces) on a cool, windy day.
2. Shut all windows, exterior doors, and fireplace flues.
3. Turn on exhaust fans or use a large window fan to suck air out of the rooms.
4. Light an incense stick and pass it around potential leak sites; observe where the smoke wavers.

This method increases infiltration through cracks and leaks, making them easier to detect.

Additional Detection Methods

• Flashlight Method: Shine a flashlight at night over potential gaps while someone observes from outside; larger cracks will show up as rays of light.
• Dollar Bill Test: Shut a door or window on a dollar bill; if you can pull it out without resistance, you may have an energy leak.

Why Sealing Air Leaks Matters

Sealing air leaks not only improves comfort but also enhances indoor air quality (IAQ). Gaps in the building envelope can lead to moisture issues, mold growth, and health problems for residents. Properly addressing these leaks creates a healthier living environment. You only get one chance to put together your building envelope correctly. Once concealed with siding or shielding, it’s nearly impossible to fix any issues later. By not focusing on this crucial aspect of construction, you risk creating pathways for leaks that can lead to poor IAQ.

Conclusion

Detecting and sealing air leaks is essential for maintaining an energy-efficient home. Whether through professional blower door tests or DIY inspection methods, identifying these gaps will help improve comfort levels and reduce energy costs. Consider scheduling an energy assessment with a qualified technician to ensure your home is as airtight as possible. By taking proactive steps now, you can enhance your home’s efficiency and create a healthier living environment for you and your family.