You’ve had a blower door test, and now you have a number: a measurement of your home’s airtightness. But what do you do with this information? This isn’t just a number; it’s a powerful tool to make your home more comfortable, energy-efficient, and healthier.
Understanding Your Results
First, understand what your blower door results mean. The lower the CFM50 (Cubic Feet per Minute at 50 Pascals of pressure) number, the tighter your home. A higher number indicates more air leakage. Your energy auditor will likely explain what constitutes a “good” or “bad” number for your specific home and climate zone. They might also provide a visual breakdown of where the major leaks are occurring.
Prioritizing Air Sealing Efforts
The beauty of a blower door test, especially when paired with a thermal camera or smoke pencil, is that it pinpoints exactly where air is escaping or entering your home. This allows you to prioritize your air sealing efforts for maximum impact.
Here are common areas for air leakage and how to address them:
- Attic Bypass Leaks: These are often the biggest culprits. Look for gaps around places like plumbing stacks, electrical wires, recessed lighting, and dropped soffits. Use caulk, expanding foam (spray foam), or rigid insulation to seal these.
- Rim Joists in Basements/Crawl Spaces: The area where your foundation meets your framing can be a major source of leaks. Seal these with caulk, expanding foam, or rigid insulation.
- Windows and Doors: While often the first thing people think of, major leaks here are less common than in the attic or rim joists. Still, check for worn weatherstripping and caulk around frames.
- Electrical Outlets and Switches: Use foam gaskets behind outlets and switch plates on exterior walls.
- Utility Penetrations: Gaps around dryer vents, exhaust fans, and pipes entering and exiting the house should be sealed.
- Ductwork: Leaky return and supply ducts can significantly impact efficiency. Seal them with mastic or foil tape (not duct tape!).
Reaping the Benefits
By systematically addressing the air leaks identified by your blower door test, you’ll start to experience significant improvements:
- Increased Comfort: No more drafts or hot/cold spots. Your home’s temperature will be more consistent throughout.
- Lower Energy Bills: Less conditioned air escaping means your HVAC system doesn’t have to work as hard, leading to noticeable savings on heating and cooling costs.
- Improved Indoor Air Quality: A tighter home can better control the entry of outdoor pollutants, allergens, and moisture. This also means your ventilation system (if you have one, or if you plan to install one) can be more effective at removing indoor pollutants.
- Reduced Noise: A tighter building envelope can also help dampen outside noise.
When to Retest?
After you’ve completed a significant amount of air sealing, consider scheduling another blower door test. This “post-retrofit” test will confirm the effectiveness of your efforts and provide a new, lower CFM50 number, validating your hard work. It’s incredibly satisfying to see the quantifiable improvement!
The blower door test isn’t just a diagnostic tool; it’s the first step towards a more comfortable, efficient, and healthy home. Take the information it provides and turn it into actionable steps for a better living environment.
Questions? Ready to schedule your test now? Call us at (630)283-2248
