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Heat Pumps
Green Building
Building Science
HVAC Design
Ventilation IAQ

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

by Brian Just • Last updated 08/2021

4.5/5 (view ratings)
522 students
1 module
1:27 hours
4 assignments

Course description

This course was originally presented at BuildingEnergy Boston 2020, a conference presented by the Northeast Sustainable Energy Association (NESEA)

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.

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Learning Objectives

Participants in this course will upon completion of this course, be able to:

  • • 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

Full course outline

Module 1 - Fossil-Fuel-Free at Last: Air-to-Water Heat Pump & Ventilation Retrofit

  • Fossil-Fuel-Free at Last: Air-to-Water Heat Pump & Ventilation Retrofit (01:27:31 hours)
  • OPTIONAL: Subscribe to NESEA Communications


Brian Just

Manager, Engineer, Vermont Energy Investment Corporation

Brian manages a team of Efficiency Vermont's residential energy consultants and works on a variety of energy efficiency initiatives at VEIC. He holds degrees from the University of British Columbia (MASc, Mechanical Engineering) and the University of Minnesota (BME, Mechanical Engineering). He is Passive House and LEED AP accredited, and currently serves as president of... Learn more


67 reviews

522 students have taken this course



by Jon Aid, Owner, Precision Hydronics 05/04/2021

I thought the course was very well done, especially for anyone less familiar with heat pumps and what it will take to convert from fossil fuel boilers.

by Jennifer Dilworth 02/26/2021

Nice job!

by Robert Mellon 01/09/2021

Very informative and packed full of great photos and documentation of the authors hands on experience

by John W 01/05/2021

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Frequently asked questions

How does this course work?

This is a free course. Enroll today and get access to all of the materials instantly. The lecture video and other materials are available any time.

How long do I have access to the materials?

For free courses there is no guarantee for how long the course materials will be available.

Is there a certificate of completion?

Certificates of completion are only provided to HeatSpring Membership subscribers. This course has not been approved by any credentialing organizations (NABCEP, AIA, USGBC etc) for Continuing Education Credits (CEUs). This course is for self education purposes only and completion does not indicate a level of professional expertise or credential.

Can I register multiple people?

Yes, this is a free course so you can share this page with other people from your group.

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