CMFRT5: If ducted system installed, measure pressure differential ≤3 Pa

Purpose

This is to ensure that there will not be a significant pressure difference in separate rooms of the house. Pressure differentials can result in poor system airflow, which may cause damage to the HVAC system and impact indoor air quality by introducing contaminants for outside the building envelope.

Criteria

Design HVAC system to operate at balanced system pressures by providing multiple returns or by installing return air pathways for rooms that can be separated from the central return via door closures.

Confirmation

The EarthCraft Technical Advisor will visually confirm compliance of criteria at the mid-construction inspection and will diagnostically test compliance of criteria at the final inspection.