In collaboration with the elected Best Practices Working Group members, the program has reevaluated the ASHRAE standards implemented in July. Effective immediately, BAS will be the program standard. Here are the new steps for this procedure:
- Contractors and sales representatives will need to review attic insulation levels to assure the customer has 7” nominal or more (accessible areas and visual inspection only).
- If there is less than 7” nominal, attic insulation and air sealing will still be required.
- If there is more than 7” nominal, the assessment should proceed where BAS is reviewed.
- HPC and APC contractors will perform blower door testing and evaluate BAS airflow results.
- If there is 100% or more of BAS, no restriction is needed.
- If there is 70%-100% of BAS, leave a written notification to the customer of the recommended (not required) mechanical ventilation.
- If there is less than 70% BAS (building tightness limit/BTL), mechanical ventilation is required.
HVAC-Only Projects
If steps 1 and 2 pass, HVAC-only installations can move forward.
Unvented Bath Fan/Mechanical Vent Weatherization Qualifier
If insulating or air sealing an unconditioned interior space that has an unvented bath fan, kitchen exhaust or mechanical exhaust, that fan must be vented to the exterior to proceed with weatherization of that area. If that area is not to be insulated or air sealed and does not communicate with other areas to be treated, it does not need to be vented.
