Tightly sealed homes need mechanical ventilation. Our Cincinnati installers design every project with a balanced ventilation strategy, typically a heat recovery ventilator (HRV) or energy recovery ventilator (ERV). Without it, air quality declines.
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Pre-foam Cincinnati homes typically test 7-12 ACH50 (air changes per hour at 50 Pascal pressure differential, the standard blower-door measure). Post-foam, the same homes typically test 3-6 ACH50. ASHRAE 62.2 ventilation guidance recommends 0.35 ACH minimum continuous for indoor air quality. A home that tested 8 ACH50 before foam and 4 ACH50 after may have moved from "leaky enough that natural infiltration covers 0.35 ACH continuous on average" to "tight enough that natural infiltration is below the IAQ minimum." The fix: an HRV or ERV sized to the home, providing controlled fresh-air introduction with energy recovery. Cincinnati climate uses ERVs more often than HRVs because summer humidity loads benefit from the moisture-recovery feature. Cost: $2,500-$5,000 retrofit for a typical 2,000-3,000 sqft home. Our Cincinnati installers spec the ventilation upgrade as part of the foam-project scope when the post-foam tightness warrants it. Cincinnati ASHRAE-compliance guidance: ASHRAE 62.2 sets continuous-ventilation requirements at roughly 7.5 CFM per occupant plus 0.01 CFM per sqft of floor area. For a typical 2,500 sqft Cincinnati home with 4 occupants, that's roughly 55 CFM continuous fresh-air requirement. An ERV sized to that flow runs $2,500-$4,500 installed and meets the requirement comfortably. Our Cincinnati installers run the math during foam-project scoping when the post-install tightness will trigger ventilation needs.