HERS Ventilation & Indoor Air Quality 3

Question 1

Combustion safety testing for atmospherically vented heating appliances in a home primarily evaluates:

Accepted Answer

Carbon monoxide production during normal operation and worst-case depressurization

Answer

AFUE rating accuracy under field conditions

Answer

Blower door leakage at the flue collar connection

Answer

Gas supply pressure at the meter under full load

Question 2

Per BPI standards, what ambient CO concentration measured in the living space triggers an 'Immediate Action Required' response during combustion safety testing?

Accepted Answer

35 ppm

Answer

100 ppm

Answer

200 ppm

Answer

400 ppm

Question 3

Which indoor air quality pollutant is of primary concern in homes with attached garages or gas-fired combustion appliances?

Accepted Answer

Carbon monoxide (CO)

Answer

Radon (Rn-222)

Answer

Formaldehyde (HCHO)

Answer

Particulate matter (PM2.5)

Question 4

Radon gas mitigation in a residential building is most effectively achieved by installing:

Accepted Answer

A sub-slab depressurization (SSD) system that vents soil gases to the exterior

Answer

An exhaust-only mechanical ventilation system with high airflow

Answer

Activated carbon air filtration at the central air handler

Answer

An ERV system with HEPA filtration on the supply airstream

Question 5

Per ASHRAE 62.2, the infiltration credit allows a reduction in required mechanical ventilation airflow when measured envelope leakage exceeds:

Accepted Answer

2 CFM25 per 100 sq ft of floor area

Answer

1 CFM25 per 100 sq ft of floor area

Answer

4 CFM25 per 100 sq ft of floor area

Answer

5 CFM25 per 100 sq ft of floor area

Question 6

In a worst-case depressurization combustion safety test, a rater creates maximum negative pressure in the zone containing combustion appliances by:

Accepted Answer

Closing all interior doors and operating all exhaust fans simultaneously

Answer

Opening all windows and exterior doors fully

Answer

Running the blower door fan at maximum speed with all windows open

Answer

Turning off the heating system and measuring ambient pressure

Question 7

Which condition would allow a HERS rater to verify a home as compliant with ventilation requirements WITHOUT requiring mechanical ventilation under ASHRAE 62.2?

Accepted Answer

The home's natural infiltration rate meets or exceeds the total ventilation requirement

Answer

The home has operable windows in every room

Answer

The home uses a high-MERV central filtration system

Answer

The home has a whole-house humidifier installed on the air handler