HVAC Indoor Air Quality and Filtration

Question 1

What does MERV stand for in air filter ratings?

Accepted Answer

Minimum Efficiency Reporting Value; higher = more efficient at capturing smaller particles

Answer

MERV (Minimum Efficiency Reporting Value) rates filter efficiency on a scale of 1-16+. Higher MERV numbers capture smaller particles more efficiently.

Question 2

What is 'sick building syndrome' (SBS)?

Accepted Answer

Occupants experiencing health symptoms linked to time spent in a building, primarily caused by poor ventilation and indoor air contaminants

Answer

SBS refers to situations where occupants experience acute health symptoms (headaches, irritation, fatigue) that appear linked to time spent in the building—often related to inadequate ventilation and indoor pollutants.

Question 3

What is the primary purpose of outdoor air ventilation in commercial HVAC systems according to ASHRAE Standard 62.1?

Accepted Answer

To dilute indoor contaminants and provide fresh air for occupant health and comfort

Answer

ASHRAE 62.1 establishes minimum ventilation rates to dilute and remove indoor-generated contaminants and provide outdoor air for occupant breathing.

Question 4

What CO2 concentration is generally considered the threshold above which occupant comfort begins to decline?

Accepted Answer

1,000 ppm

Answer

CO2 levels above approximately 1,000 ppm are associated with noticeable declines in comfort and emerging impaired cognitive performance.

Question 5

What is 'bioaerosol' contamination in HVAC systems?

Accepted Answer

Airborne biological particles (mold spores, bacteria, viruses) generated by HVAC system components or building sources

Answer

Bioaerosols are airborne biological particles including mold spores, bacteria, viruses, and allergens. In HVAC systems, they most commonly originate from wet cooling coils, condensate drain pans, and humidifiers.

HVAC Practice Test

HVAC Practice Test

HVAC Indoor Air Quality and Filtration