Certified whole-building and duct-leakage testing that satisfies ENERGY STAR Multifamily, NGBS, EarthCraft, RESNET, and code — for new construction and existing buildings across the region.
A blower door test measures the airtightness of a building’s entire envelope by mounting a calibrated fan in an exterior door frame, depressurizing (or pressurizing) the building, and measuring the airflow required to maintain a 50 pascal pressure difference. The result — CFM50 or ACH50 — quantifies how leaky the building is. A duct leakage test does the same for the HVAC duct system, measuring how much air the ducts lose to unconditioned space (outside the building envelope) at a standardized pressure.
HECS delivers both tests as a single, integrated field engagement. We depressurize the building with a blower door, depressurize (or pressurize) the duct system with a duct tester, and produce a single report that lines up with the program requirements — ENERGY STAR Multifamily, NGBS Green, EarthCraft, RESNET, the International Energy Conservation Code (IECC), and any local jurisdiction amendment.
Blower door and duct leakage testing is required at rough-in (ducts only), at final (whole building + ducts), and at performance verification (post-occupancy sampling). HECS staffs all three milestones across Kentucky, Indiana, Ohio, Tennessee, Illinois, and Missouri, with calibrated Retrotec blower door fans, DuctTester duct leakage equipment, and a single NCI-formatted report that satisfies the program of record on the first submission.
HECS delivers three engagement scopes depending on the program of record, the building type, and the rough-in vs final schedule. All three use the same Retrotec-calibrated blower door fans and DuctTester equipment, with the same NCI-formatted reporting.
Single test, one pressure
Whole-building airtightness measured at 50 Pa per ASTM E779 or RESNET 380. CFM50, ACH50, and ELA reported. Best for: code compliance, single-building projects, residential simple test.
Best for: Code compliance, single-family or small multifamily
Leakage curve
Whole-building airtightness measured at multiple pressures (typically 10–60 Pa) to derive a leakage exponent and an effective leakage area (ELA) curve. Required for ENERGY STAR MFNC and most certification programs.
Best for: ENERGY STAR MFNC, NGBS, EarthCraft, LEED
Ducts to outside
Total duct leakage measured with a DuctTester at 25 Pa to the outside, per RESNET 380 or program-specific protocol. Conducted at rough-in (with the air handler installed) and at final (post-construction).
Best for: Multifamily rough-in, single-family final, code compliance
From pre-test coordination to the final certified report, here is what HECS delivers on a blower door and duct leakage engagement.
HECS confirms the test scope, the program of record (ENERGY STAR, NGBS, code, or local jurisdiction), the test pressure, and the rough-in vs final schedule. We coordinate with the GC, the HVAC contractor, the insulation contractor, and the certification program’s sampling protocol.
If the project requires a rough-in duct test (most multifamily programs do), HECS pressurizes the duct system with a DuctTester, measures the leakage to outside at 25 Pa, and reports the CFM25 value. This catches the worst duct leaks before drywall closes up the ceiling cavities.
After the building is fully sealed (insulation, drywall, penetrations, doors, windows), HECS returns for the final blower door test (multi-point per RESNET 380 / ASTM E779) and the final total duct leakage test. Both tests are run back-to-back for efficiency.
HECS issues a single certified report with CFM50 / ACH50 / ELA, total duct leakage (CFM25 to outside), instrument calibration, and a pass/fail against the program target. For ENERGY STAR MFNC sampling, HECS coordinates the field test with the RFI and the energy model so the test result lines up with the modeled airtightness assumption.
Every HECS blower door report includes the following calibrated measurements, formatted to the program of record and the code of jurisdiction.
Calibrated blower door test at 50 pascals. CFM50, ACH50, and effective leakage area (ELA) reported per ASTM E779 or RESNET 380.
Pressures from 10–60 Pa produce a leakage curve, a flow coefficient (C), an exponent (n), and an ELA. Required for ENERGY STAR MFNC sampling and most certification programs.
DuctTester measures total leakage to outside at 25 Pa. Required at rough-in and at final per RESNET 380, ENERGY STAR MFNC, NGBS, EarthCraft, and the IECC.
When the ducts are inside conditioned space (e.g., dropped-ceiling returns), leakage to the enclosure rather than to outside is reported. Common in multifamily mid-rise.
Per-room pressure pan measurements at 25 Pa identify which rooms or zones are losing pressure through the duct system, isolating problem areas for the mechanical contractor to address before drywall close-up.
Optional infrared thermography + smoke pencil to identify the worst envelope and duct leak locations, so the GC can target air-sealing rather than over-pressurizing the test.
A certified blower door and duct leakage test is the deliverable that closes out commissioning, releases the certification, and proves the building performs as designed.
Blower door and duct leakage testing verifies that the building’s air-sealing and duct system deliver the comfort, ventilation, and indoor air quality the design promised — not the CFM the installer assumed. Occupants feel the difference; the test result is the proof.
A leaky building and leaky ducts waste 15–30% of the heating and cooling energy. The blower door test identifies the air-sealing gaps; the duct test identifies the worst duct leaks. Together, they target the highest-ROI energy improvements on the project.
ENERGY STAR Multifamily, NGBS Green, EarthCraft, LEED, and most utility rebate programs require a certified blower door test and duct leakage test at final. The report is the deliverable that releases the rebate and confirms the certification.
The 2018 / 2021 / 2024 IECC, the International Mechanical Code, and most state energy codes require blower door and duct leakage testing as a condition of certificate of occupancy. HECS reports satisfy code on the first submission.
Owners get a permanent record of the building’s airtightness and the duct system’s leakage. The report is the baseline the maintenance team references to keep the building at design performance for the next 20 years.
A certified third-party blower door and duct leakage report transfers airtightness risk from the GC and the insulation contractor to a neutral, calibrated-instrument witness. It closes out commissioning and releases retainage.
HECS is an NCI-certified testing and balancing firm. We work with general contractors, mechanical contractors, property developers, and certification programs across the region — delivering field measurements, certified reports, and the documentation owners and inspectors actually need.
Every HECS field technician holds current NCI certification. We use calibrated instruments, follow NCI-formatted reporting, and produce the documentation that commissioning authorities, code inspectors, and certification programs accept on the first review.
HECS serves commercial, multifamily, institutional, and light-industrial projects across Kentucky, Indiana, Ohio, Tennessee, Illinois, and Missouri. We staff jobs of every size — from a single building balance to a 12-building multifamily rollout — with the same team and the same reporting standard.
Blower door, duct leakage, refrigerant charge, combustion analysis, decibel, infrared, TAB, and 45L documentation — HECS delivers all of them. One contract, one schedule, one set of reports that line up with each other and with the certification program of record.
HECS blower door and duct leakage testing is the right fit for:
Tell us about the project — program, square footage, units, schedule — and we will respond with a written proposal inside two business days.
Blower door tests are required by ENERGY STAR Multifamily, NGBS Green, EarthCraft, LEED v4 / v4.1, the IECC (depending on climate zone), and most state energy codes. Multifamily programs typically require sampling per RESNET 380; single-family and small commercial projects typically require a whole-building test per ASTM E779.
CFM50 is the airflow (in cubic feet per minute) required to maintain a 50 pascal pressure difference across the building envelope. ACH50 is CFM50 normalized by the building’s volume: ACH50 = (CFM50 × 60) / Volume. Both are reported on every HECS blower door test.
A duct leakage test measures the total amount of air leaking from the duct system to outside the building envelope (or to the building enclosure). HECS uses a DuctTester to pressurize the duct system to 25 Pa and reports the total CFM25 leakage to outside. The test is required at rough-in (to catch the worst leaks before drywall) and at final.
ENERGY STAR MFNC and NGBS Green both target 0.30 CFM50 per square feet of envelope area (or per program-defined metric). IECC and most state codes set the target based on climate zone — typically 3–5 ACH50 for residential, lower for high-performance multifamily. HECS provides the program target with every proposal.
A single blower door test takes 1–2 hours. A combined blower door + total duct leakage test at final takes 2–4 hours. Multifamily sampling (3–7 units depending on building count) takes 1–2 days on site. HECS provides a project-specific schedule with the proposal.
Yes. HECS offers optional infrared thermography and smoke-pencil diagnostics to identify the worst envelope and duct leak locations. The diagnostic is run at the same visit as the blower door test, so the GC and insulation contractor can target the air-sealing rather than over-pressurizing the test.
A multi-point blower door test measures the building’s airtightness at multiple pressures (typically 10–60 Pa in 10-Pa increments). The resulting leakage curve yields a flow coefficient (C), a leakage exponent (n), and an effective leakage area (ELA). Multi-point testing is required for ENERGY STAR MFNC sampling and most certification programs.
For most multifamily programs (ENERGY STAR MFNC, NGBS, EarthCraft), yes. The rough-in test catches the worst duct leaks (disconnected runs, unsealed boots, torn flex) before drywall closes the ceiling. The final test confirms the completed system meets the target. HECS staffs both milestones on a single project.
A pressure pan test uses a calibrated pressure pan placed over a register, grille, or diffuser with the blower door running, to measure the room-side pressure differential. It identifies which rooms or zones are losing pressure through the duct system and which are sealed. HECS reports pressure pan results for every multifamily final test.
Call (859) 983-7382 or email hecs@hecsusa.com with the project name, address, square footage, number of units (multifamily), number of buildings, and the program of record (ENERGY STAR, NGBS, EarthCraft, code, or LEED). HECS responds with a written proposal inside two business days.
NCI-certified TAB that verifies design airflow and water flow at every terminal. Calibrated instruments, certified report.
Field verification, sampling, and documentation for ENERGY STAR MFNC. HECS is an ENERGY STAR MFNC verification partner.
Mechanical design review, submittal review, and value engineering for commercial, multifamily, and institutional projects.
Tell us about the project — program, square footage, units, schedule — and we will respond with a written proposal inside two business days.
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