Balanced Fresh-Air System
A balanced (supply + exhaust) fresh-air system is installed and tested.
Spec
Applies uniformly from Gold upward.
Scope
Mechanical ventilation system delivering balanced supply and exhaust airflow — HRV (heat recovery ventilator) or ERV (energy recovery ventilator).
Requirements
- 01.
Install a dedicated HRV or ERV sized to ASHRAE 62.2-2022 ventilation rates for the dwelling.
- 02.
Commission with a balance test: measured supply CFM and exhaust CFM must be within 10% of each other.
- 03.
Supply ducting must distribute fresh air to bedrooms and main living areas; exhaust ducting must pull from kitchen, bathrooms, and laundry.
Documentation
Evidence the inspector / Institute will need.
- 01.
HRV/ERV spec sheet showing sensible recovery efficiency (≥ 60% for cold climates, ≥ 70% for ENERGY STAR).
- 02.
Commissioning test report showing measured supply CFM, exhaust CFM, and the balance percentage.
- 03.
Marked floor plan showing supply and exhaust grille locations.
Guidance
HRV vs ERV — which to pick
HRV recovers sensible heat only (temperature). ERV recovers both sensible heat and latent (humidity). Use ERV in hot-humid climates (Zones 2-3) to keep summer humidity out, and in cold-dry climates (Zones 6-7) to keep winter humidity in. HRV is acceptable in mixed climates (Zones 4-5) where humidity transfer is less critical.
Resources
- ENERGY STAR HRV/ERV →
Certified product list with SRE and LRE ratings.