Guidelines for performing blower door testing (for IEQp2 in NC, CS, and CI rating systems) require that you follow ANSI/ASTM-E779-03 Standard Test Method and that sampling be performed in accordance with progressive sampling methodology defined in Ch. 4 of the Residential Manual for Compliance with California’s 2001 Energy Efficiency Standards. A LEED Credit Interpretation Request (CIR) for multifamily buildings has allowed for random sampling in one of every seven units. Results must demonstrate less than 1.25 square inches leakage area per 100 square feet of enclosure area (sum of all wall, ceiling, and floor areas).
Recommended Testing Approach
- Visual Inspection: Carried out by an experienced blower door technician before drywall is installed in any of the units. This will ensure that problem areas are addressed while they are still easily accessible.
- Testing of First Unit(s) with Drywall Installed: Early testing should be carried out in at least one unit once the drywall is installed, but before painting, finish materials, and appliances are applied. This will point out penetrations that need to be sealed between units and allow contractors to address those penetrations in the remaining units to ensure that all units meet the standard.
- Special Testing Procedures: Seal all fresh air intakes and connections to the outside; including exhaust and ventilation ducting; and penetrations through the party walls and to the outside. Seal leakage to the outside through windows and doors with painters’ tape.
Recommended Air Sealing Measures to Achieve Required Blower Door Test Results
- Identify the air barrier (the continuous boundary separating units where air cannot pass through) for each unit
- Ensure all penetrations in the air barrier are sealed with expanding foam, caulk, mastic, or another air barrier material
- A dropped ceiling does not necessarily constitute an air barrier; penetrations in walls between units and above the dropped ceiling must be sealed
- Seal and insulated chases
- Seal penetrations through top and bottom plates.
- Insulation is not enough to seal openings. Drywall is a more solid sealing material
- Seal bottom plate to floor or foundation
- Seal window and door rough openings with low expansion foam
- Seal gaps in exterior wall sheathing with primer and tape
- Seal sheathing penetrations (including exterior light fixtures)
- Seal penetrations through band joists (including exhaust ducts, etc.)
- Seal exterior walls of fireplace chase
- Seal penetrations through insulated subfloor (including HVAC boots)
- Seal around and in the walls behind shower and tub drains
- Cantilevered floor sealed and blocked above supporting wall between joists
- All recessed can lights in insulated ceilings must be airtight and IC-rated
- Seams in band joist between conditioned floors must be sealed
- Soffits above cabinets and horizontal duct work must be sealed
- Electrical and communication boxes must be sealed
- Ensure firewalls between units adequately seal units from the top to the bottom deck