With well-insulated envelopes and newer heat pumps that work in cold climates, some designers and developers are moving away from fossil fuels towards all-electric buildings. This can certainly save infrastructure costs, but what is the effect on operating costs? What about comfort and reliability? This workshop will present findings from research; case studies from the around the Northeast; and best practices for determining if, how, and when to forego fossil fuels.

The main focus will be on the two thermal loads that have been most challenging to meet without on-site fuels: space heating and water heating.

Newer air-source heat pumps (ASHPs) have been shown to work very well in some cold climate applications. Especially in low-load homes, ASHPs can efficiently provide all heating and cooling needs with reasonable installed costs. But good performance of these systems is not guaranteed! Good performance requires proper equipment selection, sizing, installation, and operation. Some real-world results will be presented along with best practices and recommendations for incorporating ASHPs most effectively.

Discussions on water heating will cover several options: simple electric tanks, tankless electric heaters, solar thermal, heat pump water heaters, etc. This portion will also include real cost and performance data from several research and evaluation projects. Pros, cons, and best practices will be discussed for different applications so participants will be able to make informed decisions about their own projects.

• Learn the basics of ASHP operation and terminology and understand how ASHPs provide heat most effectively in very cold weather (near or below 0°F).
• Learn key criteria (equipment specs, sizing, installation, and operation factors) that can result in better ASHP performance.
• Understand how new heat pump water heaters and solar thermal systems work and where they can (and where the can’t) be applied effectively.
• Be able to select appropriate ASHPs and hot water strategies and equipment for low-load home and apartment applications.