Residential Duct Air Flow Measurement: Assessing the impact of air flow on ASHP sizing

Duct capacity is often a limiting factor in sizing retrofit heat pumps, and contractors often size heat pumps based on the existing air conditioner, resulting in under-sized equipment. A simple 15-minute test can provide definitive air flow capacity of a duct system, contributing to a proper sized heat pump and avoiding poor system performance—such as noise problems due to restrictive ductwork. Energy Advisors (EA) can easily add this procedure to the scope of an Energy Evaluation.

This training will instruct EAs on how to evaluate the airflow capacity of duct systems in homes where the distribution system is not being changed and the primary retrofit measure is the replacement of heating and cooling equipment. In conjunction with other considerations—such as the CSA F280-12 Heat Loss/Heat Gain value—this is a preliminary assessment to provide the homeowner and their HVAC Contractor with data that will help the contractor select the largest ASHP based on existing ductwork. Please note: This course does not enable EAs and other HOT2000 modelers to select specific heat pumps or make direct sizing recommendations. The Contractor is ultimately responsible for equipment selection.

Instructor and CACEA member Mark Rosen MEA, Director, Building Science, Building Knowledge Canada and a well-known professional architect, trainer, and consultant who is passionate about buildings that perform exceptionally well.

TRAINING CONTENT

This course, developed in collaboration with Natural Resources Canada, will guide you through the process of measuring duct flow using The Energy Conservatory’s (TEC) TrueFlow™ meter.

The one-day training will address:

• Understanding the impact of the duct system on sizing an Air Source Heat Pump
• How to apply the basic theories of air flow to evaluate a working system
• Identifying the components of a typical duct system in order to take pressure and flow measurements at the correct locations
• How to use the TEC TrueFlow™ meter to measure air flow in an existing duct system
• How to record the air flow and other measurements in the Customer Report and provide feedback to the homeowner on the limitations that the duct system may pose