TAG discusses mandatory heat‑recovery ventilation for cold climates; members form technical questions and suggest credits path
Get AI-powered insights, summaries, and transcripts
Subscribe
Summary
A proposal to require heat‑recovery ventilation (ERV/HRV) in colder parts of the state prompted technical questions about airtightness prerequisites, installed cost assumptions and QA requirements; TAG members asked proponents to refine modeling inputs and pursue a credit or paired‑requirement approach.
The TAG reviewed a proposal that would require heat‑recovery ventilators (ERVs/HRVs) in Climate Zone 5 homes, based on an economic analysis submitted to the TAG. Proponent Michael Moore and his collaborator said a market‑blend analysis showed ERV/HRV systems become cost‑effective in that climate band and noted that balanced ventilation is already required in some multifamily low‑rise types.
Supporters said ERVs/HRVs reduce energy use and improve indoor air quality when paired with tighter building envelopes. “When you have balanced ventilation and a tight envelope, the cost‑effectiveness picture improves,” Moore said, and he noted work to raise fan efficiency and test different equipment scenarios.
Critics pressed technical and implementation concerns. TAG members asked about prerequisite airtightness (ACH50), ductwork and distribution costs, site‑specific differences, and realistic installed costs (some builders reported higher installed prices than those used in the study). Rater and QA requirements for commissioning and field verification were also discussed; Tom Alderson and others recommended clear third‑party QA and commissioning steps.
Outcome: The TAG did not adopt a mandatory requirement immediately. Members suggested either (a) leave ERV/HRV as an option that yields credits in the energy credit table, or (b) require ERV/HRV only when paired with specified airtightness levels. Several members volunteered to continue work on target fan efficacies and cost assumptions with the proponent; Michael Moore and others will refine modeling inputs and consider multiple implementation approaches.
Why it matters: Whole‑house balanced ventilation changes both energy use and indoor air quality; the proposal could raise up‑front costs and require training and QA to realize modeled savings.