HERS Combustion Safety Principles 2

Question 1

What is the primary purpose of a combustion air opening in a mechanical room?

Accepted Answer

To provide adequate oxygen for complete combustion

Answer

To exhaust flue gases to the outside

Answer

To reduce indoor humidity levels

Answer

To supply makeup air for kitchen exhaust fans

Question 2

During a worst-case depressurization test, which combination of conditions is typically induced?

Accepted Answer

All exhaust fans on, fireplace damper open, supply fans off

Answer

All windows open, all fans off

Answer

Only the furnace blower running

Answer

HVAC system on heating mode with all doors closed

Question 3

A gas water heater located in a garage must have its burner and pilot elevated at least how high above the floor?

Accepted Answer

18 inches

Answer

6 inches

Answer

12 inches

Answer

24 inches

Question 4

Which test instrument is used to measure carbon monoxide concentration in appliance flue gases?

Accepted Answer

Combustion analyzer

Answer

Manometer

Answer

Blower door

Answer

Infrared camera

Question 5

What does a yellow or orange burner flame on a natural gas appliance most likely indicate?

Accepted Answer

Insufficient combustion air causing incomplete combustion

Answer

Efficient complete combustion

Answer

Excess combustion air diluting the flame

Answer

High gas pressure at the appliance

Question 6

What is the term for the phenomenon where combustion appliance exhaust is pulled back into the living space through the flue?

Accepted Answer

Backdrafting

Answer

Short-cycling

Answer

Flue recirculation

Answer

Stack effect reversal

Question 7

Which RESNET standard governs combustion safety testing procedures for HERS raters?

Accepted Answer

RESNET/ICC 380

Answer

RESNET/ICC 301

Answer

RESNET/ACCA 310

Answer

RESNET 55