HERS - Certified Home Energy Rating System Rater Combustion Safety Principles Questions and Answers

Question 1

A HERS Rater is performing a worst-case depressurization test in a Combustion Appliance Zone (CAZ).
After establishing a baseline pressure, which of the following steps should be performed FIRST to create the worst-case scenario?

Accepted Answer

Close all exterior doors and windows.

Answer

Turn on the central forced-air system blower.

Answer

Open all interior doors.

Answer

Turn on all exhaust fans, such as clothes dryers and bathroom fans.

Question 2

During a combustion safety inspection, a HERS Rater measures an ambient carbon monoxide (CO) level of 40 ppm in the home. According to RESNET and BPI standards, what is the immediate required action?

Accepted Answer

Advise the homeowner to open windows and doors and to contact a qualified professional.

Answer

Continue with the inspection while monitoring the CO level.

Answer

Immediately turn off the combustion appliance, ventilate the area, and recommend the occupants evacuate.

Answer

Complete the spillage test before taking any further action.

Question 3

Which of the following conditions is most likely to cause backdrafting of a natural draft water heater?

Accepted Answer

Operation of a powerful, uncompensated kitchen exhaust fan.

Answer

An oversized chimney flue shared with a high-efficiency furnace.

Answer

A leaky building envelope with significant air infiltration.

Answer

Low outdoor wind speeds.

Question 4

When performing a spillage test on a natural draft gas furnace that has been off and has a cold vent, at what point during the main burner operation should spillage be assessed?

Accepted Answer

At 5 minutes.

Answer

Immediately upon burner ignition.

Answer

At 2 minutes.

Answer

After the blower fan has activated.

Question 5

A homeowner has recently air-sealed their attic and crawlspace. What is the primary combustion safety concern a HERS Rater should investigate related to this work?

Accepted Answer

Reduced dilution of potential CO spillage and increased depressurization.

Answer

Increased potential for gas leaks due to pressure changes.

Answer

Damage to the flue liner from changes in attic temperature.

Answer

Over-firing of the furnace due to restricted combustion air.

Question 6

According to RESNET Standard Chapter 8, which of these tests is a required part of a combustion safety inspection?

Accepted Answer

Gas leakage test on all appliance fittings and connections.

Answer

Heat exchanger integrity test using a camera.

Answer

Measurement of stack temperature for efficiency calculation.

Answer

Visual inspection of the thermostat for proper calibration.

A HERS Rater is performing a worst-case depressurization test in a Combustion Appliance Zone (CAZ).After establishing a baseline pressure, which of the following steps should be performed FIRST to create the worst-case scenario?

A HERS Rater is performing a worst-case depressurization test in a Combustion Appliance Zone (CAZ).
After establishing a baseline pressure, which of the following steps should be performed FIRST to create the worst-case scenario?