BPI Building Science & Envelope 4

Question 1

What is the function of a 'rainscreen gap' in an exterior wall assembly?

Accepted Answer

Creating a capillary break and drainage/drying space behind cladding

Answer

A rainscreen gap creates a pressure-equalized zone and capillary break that allows bulk water to drain and the assembly to dry.

Question 2

In building science, what does 'ACH50' represent?

Accepted Answer

Air changes per hour at 50 Pascals depressurization

Answer

ACH50 is the number of times per hour the entire volume of a house's air is replaced when the building is depressurized to 50 Pascals by a blower door.

Question 3

What is 'thermal mass' and how does it affect a building's energy performance?

Accepted Answer

The capacity of dense materials to store heat, moderating temperature swings

Answer

Thermal mass materials like concrete and brick absorb heat during the day and release it at night, reducing peak heating and cooling loads.

Question 4

Which of the following best describes the 'stack effect' in a tall building?

Accepted Answer

Pressure difference between indoors and outdoors caused by temperature-driven buoyancy forces

Answer

Stack effect occurs when temperature differences between inside and outside create buoyancy-driven pressure differences, drawing air in at low points and out at high points in winter.

Question 5

A BPI assessor finds that a crawl space has exposed soil and open vents to the outside. What is the MOST effective moisture control upgrade?

Accepted Answer

Sealing vents, installing a ground vapor barrier, and conditioning or encapsulating the space

Answer

Encapsulating the crawl space by sealing vents, covering soil, and conditioning the space dramatically reduces moisture entry and related problems.

(BPI) Building Performance Institute Certified Practice Test

(BPI) Building Performance Institute Certified Practice Test

BPI Building Science & Envelope 4