What is the purpose of using filters during the start-up of a ventilation system?

• A. To calibrate sensors.
• B. To reduce noise from equipment.
• C. To maintain indoor air quality by preventing contaminants from entering the system.
• D. To reduce energy consumption by recirculating air.

Answer: (C)

Filters used at system start-up primarily protect indoor air quality by preventing contaminants from entering the ventilation system as air begins to move. They capture dust, construction debris, pollen, and other particulates so these contaminants aren’t drawn into the ducts, coils, and sensors or distributed into occupied spaces during commissioning and early operation. This helps keep the space clean and ensures the equipment and controls read more accurate conditions.

Other options aren’t the main purpose: calibrating sensors is a separate maintenance process, noise reduction is addressed with acoustical and isolation measures, and energy savings from recirculating air aren’t achieved by filtration during start-up.