Service Area › Fairfield County

Duct Leakage Testing in Darien, CT

Same-day scheduling · Signed report on-site · Contractor pricing

Serving Darien HVAC Contractors

Darien is a compact, affluent town on Long Island Sound with predominantly single-family housing stock and a high density of HVAC replacement projects — Connecticut energy code requirements parallel New York's duct testing standards.

Westchester Duct Testing provides residential duct leakage testing for HVAC contractors throughout Fairfield County. We show up, run the test, and hand you the signed report before we leave. Same-day and next-day scheduling available. Call by 10 AM for same-day service.

Why Contractors in Darien Choose Us

⚡Same-day and next-day availability. We're based in Harrison, NY — tight Westchester geography means fast dispatch times across Fairfield County.
📋Signed report before we leave. You get the test report — with all readings, code references, and pass/fail determination — before we walk off the job. No waiting for emailed PDFs.
💲Contractor pricing. Standard tests from $450. Volume accounts (5+/month) at $375, 10+/month at $325. Re-tests $200. Transparent pricing, no surprises.
🏗️PE-backed credibility. Operated by Marcy Engineering, PLLC — a licensed professional engineering firm. Building departments trust the report.

Code Requirements

The 2025 NYS Energy Conservation Construction Code (ECCCNYS) requires duct leakage testing for all residential duct installations — including retrofits in existing buildings (R503.1.2). Maximum allowable leakage thresholds per R403.3.8:

Rough-in (AHU not installed)

≤ 3 CFM/100 sf

Rough-in (AHU installed)

≤ 4 CFM/100 sf

Post-construction

≤ 4 CFM/100 sf

Test methodology: ANSI/RESNET/ICC 380 · Pressurization at 25 Pa (0.1″ w.g.)