Combustion Safety Principles Flashcards

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

Answer: To provide adequate oxygen for complete combustion

Combustion air openings supply sufficient oxygen to support complete combustion and prevent CO production from fuel-fired appliances.

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

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

Worst-case depressurization maximizes negative pressure by operating all exhaust devices and opening fireplace dampers simultaneously.

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

Answer: 18 inches

Garage-installed water heaters must have ignition sources elevated at least 18 inches above the floor to avoid igniting gasoline vapors that pool at floor level.

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

Answer: Combustion analyzer

A combustion analyzer measures CO, CO2, O2, and flue gas temperature to assess combustion efficiency and safety.

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

Answer: Insufficient combustion air causing incomplete combustion

Yellow or orange flames indicate incomplete combustion from insufficient air, which can produce dangerous levels of carbon monoxide.

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

Answer: Backdrafting

Backdrafting occurs when negative house pressure or adverse weather conditions reverse the intended upward flow of combustion gases through the flue.

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

Answer: RESNET/ICC 380

RESNET/ICC 380 establishes standard test methods for building enclosures, including combustion safety diagnostics performed by HERS raters.