Code Readiness Final Project Report, Nonresidential Hydronic Heat Pumps: System Operation Field Study and Analysis

In 2021 PG&E’s Code Readiness Program research team (research team) initiated an evaluation and data collection of nonresidential hydronic heat pump heating equipment across California. The intent of the data collection effort was to better understand how hydronic heat pumps perform under real-world conditions. The research team proceeded to recruit four small-to-medium commercial buildings with hydronic heat pump systems and collected system performance data through the building automation system (BAS) data collection and supplemental field monitoring.

This report introduces the reader to AWHP and WWHP technology, walks through current state and federal codes, standards, and test procedures, and shares the field site observations and performance results. The report also explores the potential for utilizing thermal energy storage (TES) with AWHPs and evaluates heat recovery heat pumps through applied analyses. Lastly, the report summarizes all field study findings, Title 24 enhancement opportunities, and additional research recommendations.