Heat Pump Helpers
A Path to Approach Systems Change in Existing Homes
The Heat Pump Helpers project united local partners to help Duluth homeowners explore high-efficiency heat pump technology. Together, they showed both the opportunities and challenges of bringing greener heating solutions to existing homes.
A Collaborative Effort
Existing homes need ongoing care and attention. Planning for upgrades, repairs or replacement presents opportunities to improve the existing conditions, but the path to actual improvement isn’t always obvious. Minnesota Interfaith Power and Light (MNIPL) initiated the Heat Pump Helpers project to support Duluth-area residents in assessing the potential for existing homes to utilize high-efficiency heat pump technology. Heat Pump Helpers was a joint effort between MNIPL, Just Housing and Northern Built Pro.
Bret Pence of MNIPL conducted community outreach and information sessions about the application and potential benefit of heat pump technology for existing homes, and recruited 5 interested households for the project. Bret provided project coordination and support, and homeowner guidance about potential rebates and incentives.
Working together, Just Housing and Northern Built Pro performed energy audits on five Duluth-area households and assessed the potential and suitability of each home for the adoption of heat pump technology for heating, cooling and domestic hot water. We evaluated existing conditions, mechanical systems, and energy consumption of each home through the lenses of health and safety, durability, and energy efficiency. Test results, analysis and recommendations were documented in a report to each homeowner, which they can use to consider and pursue retrofit work.
Ready for Change
One homeowner was immediately ready to explore the recommendations in their assessment report, and hired Just Housing to help guide the follow-up steps to consider and select improvements. We share some details of their story.
The Mikkonen House is a 1400 ft2, rural 2-story home built in 2003. The owners had the goal of transitioning their home off the use of propane, and a sense of urgency about decision-making since their propane water heater (a super-efficient condensing water heater used for both domestic hot water and space heating) was nearing the end of its useful life.
To accurately determine the home’s heating and cooling needs and appropriately size the new equipment, we created an energy model of the house and its soon-to-be-built greenhouse. We provided some design feedback for the new planned greenhouse with regard to high performance details and to help integrate it with the existing structure. We also analyzed the potential for incorporation of a heat pump water heater. Our analysis determined that full electrification was a viable route forward.
We recommended separating the systems that the propane water heater served, with a heat pump water heater for hot water and an air-to-water heat pump (AWHP) for space heating. With separate equipment, if one goes out the other still works. The AWHP can be sized and optimized for the existing low-temp space heating distribution system (hydronic radiant tubing in the floors), since it doesn’t need to heat domestic hot water.
We worked with the owners and the technical support team from Arctic Heat Pumps to select their new air-to-water heat pump water heater (AWHP) and facilitate the replacement of their existing propane-fired condensing water heater. The new system utilizes almost all of the original piping, and retains the home’s in-floor heating system. The back-up electric boiler can provide supplemental heating if and when the AWHP can’t meet the demand.
Results
The owners, who are both scientists, were very interested in incorporating the air to water heap pump, seeing it as an appropriate replacement technology for their goals and existing conditions, despite the technology being relatively unknown in northern Minnesota. The owners had their share of hiccups with the process to identify, install and commission the new heating system in their home, but they used their research skills to diagnose and fix the problems they encountered, and they are happy with the result. They also report that they believe the AWHP technology isn’t yet ready for widespread adoption in the region. Nonetheless, due in no small part to the diligence and keen awareness of its owners, the Mikkonen House is now comfortably served by one of the region’s first air-to-water heat pumps.
For us at Just Housing, this project exemplifies what we hope to do in our work:
Provide assistance to residents and others seeking to improve the comfort, durability and environmental impact of homes.
Participate in the development and distribution of green solutions with widespread application for both new and existing homes.
Collaborate with community members to empower stakeholders and advance opportunity and participation in green building.
