Whole-house mechanical ventilation per ASHRAE 62.2 (typically 7.5 cfm/person + 3 cfm/100 sqft, balanced when possible)
ENERGY STAR SFNH §Mechanical ventilation — ASHRAE 62.2 compliantDescription
ENERGY STAR requires a whole-house mechanical ventilation system designed per ASHRAE Standard 62.2. The typical calculation: 7.5 cfm per occupant (default 2 + bedrooms count) plus 3 cfm per 100 sqft of conditioned floor area. Cold climates strongly favor balanced ventilation (HRV or ERV) over single-port supply/exhaust strategies. Bath + kitchen local exhausts are separate from the whole-house ventilation.
Why this exists
Tight envelopes (≤ 3 ACH50) cannot rely on infiltration; mechanical ventilation is mandatory for healthy IAQ. Architects designing to ENERGY STAR should plan ERV/HRV ducting from the start — running fresh-air supply to bedrooms and stale-air return from bathrooms is the standard layout.
Categories
Source
Solver enforcement
Browsable only — the solver does not currently enforce this directive (no spec-level data to check against). This entry exists so the architect personas can cite it in conversation and the user can read what the rule says.
Related directives
- Slab-on-grade vapor barrier + capillary break required · HUD RSDG §4.6
- Roof overhangs protect walls — 12-24 inches in humid climates; one foot per story below · HUD RSDG §5.6.5
- ENERGY STAR certification: HERS-index target + Rater field checklist + HVAC quality install · ENERGY STAR SFNH §Overview — Certification path
- Grade I insulation installation: no gaps, no compression, fully filling cavity, supported aligned with air barrier · ENERGY STAR SFNH §Rater Field Checklist — Section 1 (Insulation + Air Barrier)
- Continuous air barrier on all six sides of conditioned space — including rim joists, knee walls, attic floor · ENERGY STAR SFNH §Air Barrier — continuous on all six sides of every conditioned space
Last reviewed 2026-05-15.