Finally Fossil-Fuel-Free: Air-to-Water Heat Pump & Ventilation Retrofit

Air-to-water heat pumps have generated a lot of excitement for their enormous retrofit potential. This case study details one home’s retrofit to an AWHP system, which was developed by hydronics experts to be simple and repeatable. The project encompassed distribution systems, domestic hot water and backup heat, as well as a ventilation system upgrade from exhaust-only to high-efficiency fresh air (balanced) ventilation. We’ll present full project costs, before/after breakdown of energy models/costs, details on the beyond-energy motivations and benefits gained by the homeowners, and we’ll share extensive data from this project’s comprehensive monitoring systems along with two other installations in Vermont. We’ll summarize lessons learned and the limitations and challenges in designing for air-to-water retrofittability. There will be ample time for lively Q&A.

Session Speaker(s): 

Session Chair(s): 

Event Time: 

Thursday, August 13, 2020 - 9:15am to 10:45am

Experience Level: 

2 (some prior experience/knowledge helpful)

CEU Information: 

AIA 1.5 LU/HSW
BPI 1.5 hours
GBCI BD+C, ID+C 1.5 hours
MA CSL 1.5 hour, Energy

Learning Objectives:

  • Describe how air-to-water heat pumps are functioning in a climate as harsh as New England's
  • Identify 5 key non-energy benefits that can help move the needle on HVAC retrofit projects
  • Understand the basics of how to install an air-to-water heat pump with the benefit of an open-source design and detailed photographs
  • Explain the key design features and options for low-temperature distribution, including how to set up a new home for near-seamless retrofittability in the future at minimal cost

Session ID: 

BOS20-101