Conduct room-to-room pressure tests
Pressure imbalances inside the house can lead to moisture problems in exterior walls.
To identify room-to-room pressure imbalances, a technician turns on the air handler, closes all interior doors to the room, and uses a two-station, hand-held manometer, a device that measures the pressure of liquids or gases. The acceptable pressure difference from room to room is 3 Pascals. Correcting imbalances in existing homes typically involves either trimming doors by at least 1.5 inches or cutting offset transfer grilles just above bedroom doors. The former may not be acceptable to the homeowners and is rarely sufficient, and the latter is an invasive operation, particularly if load-bearing walls are involved.
Green points
LEED for HomesLeadership in Energy and Environmental Design. LEED for Homes is the residential green building program from the United States Green Building Council (USGBC). While this program is primarily designed for and applicable to new home projects, major gut rehabs can qualify.
Up to 1 pt. for demonstrating that room-to-room pressure differences are no greater than 2.5 Pa; up to 2 pts. for a third-party performance test (EQ 6).
NGBSNational Green Building Standard Based on the NAHB Model Green Home Building Guidelines and passed through ANSI. This standard can be applied to both new homes, remodeling projects, and additions.
/ICC-700: 8 points for demonstrating balanced HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. air flows with a flow hood or other acceptable flow measurement tool (704.6.2.3).
Learn more in the Green Building Encyclopedia
Further Resources
Specifications for the Low-Income Weatherization Program, Version April 2007
