Energy Auditing Flashcards

What does a blower door test measure in a residential energy audit?

Answer: Air leakage rate of the building envelope

A blower door test depressurizes the home to measure air infiltration through the building envelope in CFM50 or ACH50.

Which BPI standard unit is used to express overall building air leakage from a blower door test?

Answer: CFM50

CFM50 (cubic feet per minute at 50 Pascals of depressurization) is the standard BPI unit for reporting whole-building air leakage.

During a combustion safety test, what is the maximum acceptable CO level in undiluted flue gases from a natural draft furnace per BPI standards?

Answer: 400 ppm

BPI standards require that CO in undiluted flue gases not exceed 400 ppm for natural draft appliances.

What is the purpose of a duct blaster test in an energy audit?

Answer: Determine duct system air leakage to the outside

A duct blaster pressurizes the duct system to quantify leakage, particularly leakage to unconditioned spaces.

An energy auditor finds a draft hood equipped water heater failing the worst-case CAZ depressurization test. What is the appropriate immediate action?

Answer: Red-tag the appliance and notify the homeowner

A failed worst-case depressurization test indicates a spillage/backdrafting hazard; the auditor must red-tag the appliance and inform the occupant.

What does the term 'thermal bypass' refer to in building science?

Answer: Airflow that carries heat around or through insulation

A thermal bypass occurs when air movement carries heat around insulation, dramatically reducing its effective R-value.

Which of the following best describes the 'stack effect' in a building?

Answer: Pressure-driven air movement caused by temperature difference between inside and outside

The stack effect is buoyancy-driven air infiltration where warm indoor air rises and escapes at the top, drawing cold outside air in at the bottom.