BPI Air Sealing 4 — Questions and Answers
Question 1: A home has a measured ACH50 of 12 before air sealing. After work is completed, it measures 8. What is the percent improvement?
- 25%
- 33% (Correct answer)
- 40%
- 50%
Correct answer: 33%
A reduction from 12 to 8 ACH50 represents a 33% improvement: (12-8)/12 × 100 = 33.3%.
Question 2: What material is NOT recommended for air sealing applications in high-temperature areas near flues or chimneys?
- Sheet metal
- High-temperature caulk
- Latex acoustical sealant (Correct answer)
- Intumescent sealant
Correct answer: Latex acoustical sealant
Standard latex acoustical sealant is not rated for high-temperature applications and can off-gas or fail near chimneys and flues.
Question 3: In the context of BPI standards, what is the 'house as a system' principle as applied to air sealing?
- Treating each room independently for air leakage
- Understanding that sealing one area can affect pressure, combustion safety, and ventilation throughout the whole home (Correct answer)
- Installing the same amount of air sealing material on all walls
- Ensuring each system (plumbing, electrical, HVAC) is sealed separately
Correct answer: Understanding that sealing one area can affect pressure, combustion safety, and ventilation throughout the whole home
Air sealing changes building pressure dynamics, potentially affecting combustion appliance safety and indoor air quality, requiring a whole-system approach.
Question 4: What is the purpose of a 'worst-case depressurization test' performed before air sealing work?
- To find the maximum CFM50 reading possible
- To determine if combustion appliances are at risk of backdrafting under typical operating conditions (Correct answer)
- To identify the largest single air leakage site
- To test the structural integrity of the building envelope
Correct answer: To determine if combustion appliances are at risk of backdrafting under typical operating conditions
The worst-case depressurization test simulates the most severe pressure conditions to identify combustion appliance backdraft risk before tightening the home.
Question 5: Which air sealing measure addresses the 'attic bypass' pathway at dropped soffits above kitchen cabinets?
- Installing rigid foam on top of cabinets only
- Sealing the interior top of the soffit with drywall and caulk or foam before insulating (Correct answer)
- Adding insulation inside the soffit cavity
- Applying weatherstripping around cabinet doors
Correct answer: Sealing the interior top of the soffit with drywall and caulk or foam before insulating
Dropped soffits above cabinets often connect to wall cavities that bypass to the attic; sealing the top of the soffit before insulating stops this pathway.
Question 6: According to BPI protocols, what minimum ventilation rate should be ensured after aggressive air sealing of a home?
- Natural infiltration alone is always sufficient
- Mechanical ventilation per ASHRAE 62.2 should be verified or installed (Correct answer)
- Window opening schedules posted for occupants
- One exhaust fan per 500 sq ft of floor area
Correct answer: Mechanical ventilation per ASHRAE 62.2 should be verified or installed
After aggressive air sealing, BPI requires verifying mechanical ventilation meets ASHRAE 62.2 standards to maintain acceptable indoor air quality.
Question 7: What is the primary function of backer rod in an air sealing application?
- To reinforce caulk joints in high-stress areas
- To provide a backing that controls sealant depth and prevents three-sided adhesion in wide gaps (Correct answer)
- To add R-value behind exterior foam sealant
- To create a fire-resistant barrier before applying foam
Correct answer: To provide a backing that controls sealant depth and prevents three-sided adhesion in wide gaps
Backer rod fills wide gaps to control the depth of sealant application and prevents three-sided adhesion, which causes premature sealant failure.
BPI Air Sealing 4
A home has a measured ACH50 of 12 before air sealing.
After work is completed, it measures 8.
What is the percent improvement?