BPI Building Science & Envelope 3

Question 1

A homeowner reports that their attic insulation was installed directly over soffit vents. What is the PRIMARY concern with this installation?

Accepted Answer

Blocked ventilation causing moisture and thermal problems

Answer

Blocking soffit vents prevents attic ventilation, which can lead to moisture accumulation, ice dams, and increased cooling loads.

Question 2

What does the term 'hygric buffering' describe in building science?

Accepted Answer

A material's ability to absorb and release moisture, moderating humidity swings

Answer

Hygric buffering refers to a material's capacity to temporarily store moisture and release it slowly, stabilizing indoor relative humidity.

Question 3

What is 'interstitial condensation' in a building assembly?

Accepted Answer

Condensation forming within the wall, floor, or roof assembly between layers

Answer

Interstitial condensation occurs when warm, moist air reaches a surface within a building assembly that is at or below the dew point temperature.

Question 4

According to BPI standards, what is the recommended maximum relative humidity for conditioned living spaces during winter to prevent moisture problems?

Accepted Answer

50%

Answer

BPI and ASHRAE 160 recommend maintaining indoor relative humidity below 50% to reduce the risk of moisture damage and mold growth.

Question 5

A blower door test measures a house at 1,800 CFM50. The house has 2,000 square feet of conditioned floor area. What is the air leakage rate in CFM50 per square foot?

Accepted Answer

0.90

Answer

1,800 CFM50 ÷ 2,000 sq ft = 0.90 CFM50/sq ft, which is a common metric for normalized air leakage.

(BPI) Building Performance Institute Certified Practice Test

(BPI) Building Performance Institute Certified Practice Test

BPI Building Science & Envelope 3