ASHRAE 62.2-2022 in Tight Kentucky Homes: What Field Testing Actually Shows

Field findings from HECS residential ventilation compliance work across Kentucky and southern Indiana, 2024-2026.

The Pattern HECS Sees in 2026 Field Work

Two things happen simultaneously as builders chase the 2024 IECC airtightness target. Envelope leakage drops — often well below the binding limit — and mechanical ventilation gets under-designed, misbalanced, or never commissioned. The result is a tight shell with inadequate outdoor air, and homeowners who call back about stale bedrooms, condensation on north windows, and range hoods that move almost nothing.

Kentucky sits in IECC climate zones 4A and 5A. Under 2024 IECC Table R402.4.1.1, the binding blower-door limit for both zones is 3.0 ACH50 — not 5.0. HECS routinely measures 1.5-2.5 ACH50 on ENERGY STAR and NGBS projects. A tight envelope is the goal, but tightness alone does not satisfy ASHRAE 62.2-2022 §4.1, which requires a calculated whole-building mechanical ventilation rate independent of envelope leakage.

The failure mode is consistent: builder assumes the blower door result covers fresh-air delivery. Code official signs off. Year two, the homeowner complains. HECS gets the call to document what is actually being delivered at the grille.

What ASHRAE 62.2-2022 Actually Requires

Per ASHRAE 62.2-2022 §4.1, total whole-building ventilation must meet Q_total = 0.03·A_floor + 7.5·(N_br+1) cfm, where A_floor is conditioned floor area and N_br is the bedroom count. For a 2,400 ft², four-bedroom home, that works out to roughly 110 cfm combined supply and exhaust — not a trivial number once you measure what the equipment actually delivers.

Three additional requirements drive most of HECS's field findings:

• §4.1.4 filtration credit (updated by Addendum a, February 2024) — MERV-rated HVAC equipment can reduce the required mechanical rate, but only when filtration is verified and the equipment is commissioned to design airflow. HECS sees builders claim the credit on paper while the system runs at 60% of nominal CFM.
• §4.3 local exhaust — kitchens need ≥100 cfm intermittent (or ≥25 cfm continuous) at the range hood; bathrooms need ≥50 cfm intermittent. HECS measures kitchen hoods in the 40-70 cfm range on roughly half of tight homes.
• §4.4 ventilation opening area — the infiltration credit is capped at the lesser of 2 ACH50 or 0.04·A_floor / 7.6 cfm. In a 1.8 ACH50 home, the infiltration credit is near zero, and the entire ventilation load falls on the mechanical system.

Working with HECS

HECS handles indoor-air-quality documentation — blower door, duct leakage, and ventilation verification — for builders in Kentucky, Indiana, Ohio, Tennessee, Illinois, and Missouri. For a scope call on a tight-home project: (859) 983-7382 or hecsusa.com/contact/.

What HECS Verifies on Site

HECS residential ventilation work falls under the HECS indoor-air-quality service line, with procedures aligned to NCI airflow measurement methodology. The deliverable is a single report that pulls every air-side metric into one document for code officials, ENERGY STAR reviewers, NGBS verifiers, and 45L certifiers.

Field procedure on a typical tight Kentucky home:

• Blower door at 50 Pa per ASTM E779, with leakage-to-outside quantified using a second guarded blower door or zone pressure diagnostics when the result must be airtightness-only.
• Duct leakage to outside per 2024 IECC R403.3.5 — verified total leakage ≤ 4 CFM25 per 100 ft² conditioned floor area.
• HVAC airflow at the handler measured with a flow plate or capture hood, not nameplate. Fan curves at 0.6-0.8 in. w.c. external static pressure routinely drop residential equipment below design.
• Range hood and bath exhaust measured with a capture hood at the grille or terminal. HECS records static pressure and actual CFM, not the manufacturer's brochure number.
• Fresh-air inlet CFM for HRV/ERV or barometric damper — verified against the ASHRAE 62.2-2022 equation result.

Common Pitfall: Treating the Blower Door as a Ventilation Test

It is not. The blower door measures envelope leakage at a 50 Pa pressure difference — an unrealistic operating condition for the house. ASHRAE 62.2-2022 separates envelope performance from ventilation delivery. Code officials who accept a passing blower door as evidence of compliance miss the point of §4.1 entirely.

HECS project data from 2024-2026 shows the gap: homes at 1.8-2.4 ACH50 with whole-building ventilation rates running 20-40% below the §4.1 equation result. The most common culprit is a fresh-air inlet that was sized on paper but never verified at the operating static pressure of the installed filter and duct run. A MERV 13 filter alone can drop residential airflow 10-15% off design.

For ENERGY STAR MFNC projects, v1.3 (Rev05) requires the HVAC Functional Testing Checklist for every participating unit. The checklist is the operational proof that §4.1 is met, not a paperwork exercise. HECS finds that the checklist is completed but airflows are not actually measured in roughly one of three projects.

For NGBS-2023 projects, Chapter 7 and §903 reference ASHRAE 62.2-2022 directly. The verifier of record must sign off on ventilation delivery, not just envelope tightness.

Frequently Asked Questions

Does a passing blower-door test satisfy ASHRAE 62.2-2022?

No. The blower door verifies envelope airtightness against the 2024 IECC Table R402.4.1.1 limit of 3.0 ACH50 for Kentucky climate zones. ASHRAE 62.2-2022 §4.1 requires a separate calculated mechanical ventilation rate based on floor area and bedroom count. HECS documents both as distinct line items in the same report.

Can MERV filtration reduce the required mechanical ventilation rate?

Yes, but only per ASHRAE 62.2-2022 §4.1.4 as updated by Addendum a (February 2024), and only when the credit is supported by verified airflow at the equipment. HECS measures handler CFM at installed filter and static pressure before claiming the credit on a project.

What is the most common ASHRAE 62.2 failure on tight Kentucky homes?

Range hood airflow below the §4.3 kitchen requirement, paired with a fresh-air inlet that delivers less than design CFM. HECS project data shows this combination on roughly half of tight homes measured since 2024. The fix is usually a damper adjustment or a larger hood — not a system redesign.

How to Engage HECS

HECS is NCI-certified and based in Louisville, serving Kentucky, Indiana, Ohio, Tennessee, Illinois, and Missouri. For ASHRAE 62.2-2022 verification, HECS scopes blower door, duct leakage, and ventilation airflow measurement into a single field visit. Reports are formatted for code officials, ENERGY STAR MFNC reviewers, NGBS-2023 verifiers, and 45L certifiers. Reach HECS at (859) 983-7382 or hecs@hecsusa.com to schedule. Service details are at hecsusa.com/services/ and project intake at hecsusa.com/contact/. HECS covers Louisville KY, Lexington KY, Cincinnati OH, Indianapolis IN, Nashville TN, and Evansville IN as primary city clusters, with reach across the full six-state service area.