HERS Diagnostic and Field Testing 3

Question 1

What is the primary purpose of performing a combustion safety test during a HERS rating?

Accepted Answer

To identify carbon monoxide spillage or backdrafting risks in combustion appliances

Answer

Combustion safety testing identifies dangerous conditions where combustion byproducts such as carbon monoxide can spill back into living spaces from appliances like furnaces and water heaters.

Question 2

Which test condition is considered 'worst case' for combustion safety testing of atmospherically vented appliances?

Accepted Answer

All exhaust fans on, interior doors closed to maximize depressurization

Answer

Worst-case depressurization with all exhaust fans operating and interior doors closed creates the greatest negative pressure that could cause backdrafting.

Question 3

When using a calibrated manometer to measure pressure difference across the building envelope, the reference port (Channel B) should be placed:

Accepted Answer

Outside in an undisturbed location

Answer

The reference port must be placed outdoors in a sheltered, undisturbed location to accurately measure the pressure difference between inside and outside.

Question 4

A HERS rater finds a CO reading of 35 ppm in the flue gases of a natural draft water heater. What is the appropriate action?

Accepted Answer

Immediately notify the homeowner and recommend appliance service before occupancy

Answer

Any CO detected during combustion safety testing should be reported to the homeowner and serviced before occupancy, as CO poses an immediate health and safety risk.

Question 5

What does 'spillage' mean in the context of combustion appliance zone (CAZ) testing?

Accepted Answer

Combustion byproducts escaping from the draft hood into the living space

Answer

Spillage occurs when combustion gases escape through the draft hood or diverter of an atmospherically vented appliance into the surrounding zone instead of exhausting through the flue.

(HERS) Certified Home Energy Rating System Rater Practice Test

(HERS) Certified Home Energy Rating System Rater Practice Test

HERS Diagnostic and Field Testing 3