This session will explore the connection between whole building air leakage values as measured via blower door testing, and typical HVAC-industry heating and cooling load calculations. The presentation will analyze the power-law equation (produced by a blower door test) that represents the building leakage curve, Q = C(dP)n , and how the info that this equation produces is related to infiltration values that are commonly used in HVAC load sizing calculations (e.g. Manual J). Discussion will include current methods of estimating ‘natural’ building air leakage, both from measured flow rates and by using default component values.

Learning Objectives:

1. Review methods of estimating and defining ‘natural’ air leakage rates common to the ABAA community.
2. Introduce basic methods of estimating and defining ‘natural’ air leakage rates common to the HVAC industry.
3. Analyze the power-law equation that describes the building leakage curve, Q = C(dP)n
4. Discuss the potential impact of multi-point airtightness testing on HVAC load sizing calculations.

Nate Gusakov, BPI (BA + EP), CxA+BE, BECx

Nate Gusakov was born and raised in Bristol VT, between the New Haven River and the foothills of the Green Mountains. For two-plus decades he worked as a frame-to-finish carpenter in climate zone 6, most recently installing AeroBarrier with Zone 6 Energy/Silver Maple Construction. Since 2017 Nate has been offering residential and commercial airtightness testing, building envelope assessments, building enclosure commissioning (BECx) services and general envelope consulting and diagnostics. He has performed many hundreds of blower-door tests on buildings ranging from tiny houses to 100,000 square feet and in 2023 founded his own business, Green Mountain Enclosure Consulting llc.