ERV/HRV Sizing Calculator

Size whole-house balanced ventilation by ASHRAE 62.2, choose ERV or HRV by climate, and lay out duct size, local exhaust, and defrost recommendations.

Default sizing example

  • ASHRAE 62.2 ventilation rate: 75 CFM
  • Recommended system in zone 5A: ERV
  • Recommended duct: 6 in round
  • Local exhaust: 100 CFM kitchen, 50 CFM each bathroom

All tools ยท Building envelope guides