HERS Building Science Fundamentals 2

Question 1

In a mixed-humid climate, what is the primary moisture concern during summer months?

Accepted Answer

Warm humid outdoor air infiltrating and condensing on air-conditioned surfaces

Answer

In mixed-humid climates, warm humid outdoor air infiltrating a cooled building can condense on surfaces below the dew point, causing moisture damage.

Question 2

Which term describes the total heat flow through a building assembly per unit area per unit temperature difference?

Accepted Answer

U-factor

Answer

U-factor (thermal transmittance) measures heat flow rate through an assembly per square foot per degree Fahrenheit of temperature difference.

Question 3

What is 'stack effect' in a building context?

Accepted Answer

Pressure-driven airflow caused by buoyancy differences between indoor and outdoor air

Answer

Stack effect occurs when indoor-outdoor temperature differences create buoyancy-driven pressure differences that drive air infiltration and exfiltration.

Question 4

A home in Climate Zone 5 has a cathedral ceiling. Which insulation approach best controls both thermal performance and moisture?

Accepted Answer

Unventilated assembly with sufficient vapor-impermeable insulation above the roof deck

Answer

An unventilated cathedral ceiling in CZ5 requires enough rigid foam above the deck to keep the sheathing above the dew point, preventing condensation.

Question 5

What does the term 'thermal bridging' refer to in wall assemblies?

Accepted Answer

Conductive heat loss through high-conductivity elements that bypass insulation

Answer

Thermal bridging occurs when conductive materials like steel or wood studs create a path for heat to bypass the insulation in a wall cavity.

(HERS) Home Energy Rater Certification Practice Test

(HERS) Home Energy Rater Certification Practice Test

HERS Building Science Fundamentals 2