Indoor Air Quality and Filtration Flashcards
7 cards from real HVAC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Indoor Air Quality and Filtration flashcards as text
Which ASHRAE standard provides minimum ventilation rates for acceptable indoor air quality in commercial buildings?
Answer: ASHRAE 62.1
ASHRAE Standard 62.1 establishes minimum outdoor air ventilation rates and IAQ requirements for commercial and institutional buildings.
High relative humidity indoors (above 60%) most directly encourages which IAQ problem?
Answer: Mold and mildew growth
Relative humidity above 60% creates conditions that promote mold and mildew growth on surfaces and inside duct systems.
What is the function of a bypass humidifier in an HVAC system?
Answer: It adds moisture to a portion of airflow diverted from the supply plenum across a water panel
A bypass humidifier diverts a portion of warm supply air through a moistened evaporator pad and returns it to the return plenum, adding humidity to the circulated air.
Sick Building Syndrome (SBS) is most directly associated with which HVAC-related cause?
Answer: Inadequate ventilation and accumulation of indoor pollutants
SBS symptoms — headaches, fatigue, and irritation — are most commonly linked to poor ventilation that allows indoor pollutants to accumulate.
Which type of UV light system is installed in the HVAC return air stream to reduce airborne biological contaminants?
Answer: In-duct UV-C air purifier
In-duct UV-C systems installed in the return airstream irradiate passing air to inactivate bacteria, viruses, and mold spores.
What does the term 'source control' mean in the context of indoor air quality management?
Answer: Eliminating or reducing the pollutant at its point of origin
Source control means addressing the IAQ problem at its origin — such as sealing radon entry points or using low-VOC materials — rather than diluting or filtering afterward.
A technician measures a static pressure drop across a filter that is significantly higher than the manufacturer's rated clean pressure drop. What does this most likely indicate?
Answer: The filter is loaded with captured particles and needs replacement
Elevated pressure drop across a filter compared to its clean baseline indicates accumulated dust and debris loading, meaning the filter should be replaced.