HVAC System Evaluation Flashcards
7 cards from real HERS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 HVAC System Evaluation flashcards as text
When performing a HERS duct leakage test, what does 'Total Duct Leakage' measure?
Answer: Combined leakage from both supply and return ducts to outside and inside conditioned space
Total duct leakage measures combined air loss from both supply and return ducts, including leakage to unconditioned spaces and outside.
Which RESNET standard defines the protocol for HVAC system testing in HERS ratings?
Answer: RESNET/ICC 380
RESNET/ICC 380 is the standard that establishes test methods for building envelope and HVAC systems used in HERS ratings.
A home has a heat pump with a HSPF of 8.2. What does HSPF measure?
Answer: Heating season performance in BTUs per watt-hour
HSPF (Heating Seasonal Performance Factor) measures a heat pump's heating efficiency as total BTUs delivered per watt-hour consumed over a heating season.
During a HERS inspection, a rater finds that supply registers are located in the floor of a vented crawlspace. What is the primary energy concern?
Answer: Ducts in unconditioned crawlspaces are subject to thermal losses and infiltration
Ducts running through unconditioned crawlspaces lose conditioned air to thermal conduction and duct leakage, significantly reducing system efficiency.
What is the minimum SEER2 rating required for a central air conditioner to qualify as efficient under current federal standards (effective 2023)?
Answer: 14 SEER2 in northern states, 15 SEER2 in southern states
As of January 1, 2023, the federal minimum efficiency is 14 SEER2 for the North region and 15 SEER2 for the South and Southwest regions.
A HERS rater is evaluating refrigerant charge on a split-system AC. Which field verification method is most commonly referenced in RESNET guidelines?
Answer: Superheat or subcooling measurement at the outdoor unit
RESNET references superheat (for fixed-orifice systems) or subcooling (for TXV systems) measurement as the standard field method to verify proper refrigerant charge.
In ACCA Manual J load calculations used for HERS ratings, what does the 'design temperature difference' refer to?
Answer: The gap between indoor design temperature and outdoor design dry-bulb temperature
Design temperature difference is the gap between the desired indoor temperature (typically 70°F) and the local outdoor design dry-bulb temperature used to size HVAC equipment.