HERS Ventilation & Indoor Air Quality

Question 1

Which ASHRAE standard governs minimum mechanical ventilation requirements for residential buildings rated under the HERS program?

Accepted Answer

ASHRAE 62.2

Answer

ASHRAE 62.2 is specifically the ventilation standard for low-rise residential buildings, which applies to homes evaluated under the HERS rating system.

Question 2

Using the ASHRAE 62.2 formula, what is the minimum required whole-building mechanical ventilation rate for a 1,500 sq ft home with 3 bedrooms?

Accepted Answer

45 CFM

Answer

The ASHRAE 62.2 formula is 0.01 × floor area + 7.5 × (bedrooms + 1) = 0.01×1,500 + 7.5×4 = 15 + 30 = 45 CFM.

Question 3

In a tight home with a blower door result at or below 3 ACH50, ASHRAE 62.2 requires mechanical ventilation primarily to:

Accepted Answer

Dilute indoor pollutants and maintain acceptable indoor air quality

Answer

Mechanical ventilation in tight homes ensures sufficient fresh air exchange to dilute pollutants like CO2, VOCs, and moisture that accumulate when natural infiltration is insufficient.

Question 4

Per ASHRAE 62.2, the measured airflow of a mechanical ventilation system must be within what tolerance of the design rate to be considered compliant?

Accepted Answer

±10%

Answer

ASHRAE 62.2 requires that measured ventilation airflow be within ±10% of the design airflow rate to confirm the system is performing as intended.

Question 5

Which of the following ventilation system types provides the greatest control over both supply and exhaust airflow rates in a residence?

Accepted Answer

Balanced ventilation

Answer

Balanced ventilation systems control both supply and exhaust airstreams independently, providing the most precise management of ventilation rates and building pressurization.

(HERS) Home Energy Rater Certification Practice Test

(HERS) Home Energy Rater Certification Practice Test

HERS Ventilation & Indoor Air Quality