Recent Project Review with City of Vancouver
Ecolighten has recently completed a couple of research projects with the City of Vancouver on residential heat pump retrofits and is excited to share a summary of some insights and findings in this post.
With the City of Vancouver’s objective to draw 100% of its energy from renewable sources by 2050 for existing homes, there is no doubt that heat pumps will play a significant role in helping the City achieve its greenhouse gas (GHG) reduction goals. Yet, many challenges and opportunities still exist for existing gas homeowners to pursue an electrification pathway with heat pumps.
To help lower those barriers, the City of Vancouver engaged Ecolighten to explore and identify opportunities and potential limitations associated with 1) air-to-water heat pump retrofit for hydronic homes, and 2) dual fuel heat pump technologies as a displacement option to the full electrification pathway.
AIR-TO-WATER HEAT PUMP RETROFIT
BACKGROUND: According to the CoV’s recent analysis on over 1,000 existing homes, nearly 30% of the existing gas homes in Vancouver have boilers and a large portion of these boiler are reaching the end of lifecycle. Since most of those homes do not have existing ductwork, homeowners require an alternative decarbonization solution to standard forced air heat pump retrofit option, especially when they want to retain radiant heat comfort.
FIELD RESEARCH METHODOLOGY: To understand hydronic homeowners’ contexts and needs, preliminary interviews with nine (9) individual participants in Vancouver were completed followed by eight (8) in-home site visits to identify the technical and practical challenges and opportunities associated with air-to-water heat pump retrofits.
KEY FINIDINGS FROM INTERVIEWS/SITE SURVEYS:
- Consumer Vulnerability – Homeowners are very reliant on the HVAC contractors when determining appropriate solutions for their homes, but they may not be armed with the ability to properly vet contractor recommendations and approaches. Consumer supports and technical literacy improvements are urgently needed.
- Contractor Experience – Experienced contractors with technical competency to deliver air-to-water heat pump solutions is limited when compared to air-to-air heat pump solutions for existing homes. Participant feedback on their engagement with contractors highlighted the need to increase contractor knowledge, capabilities and market interests in providing air to water heat pump solutions.
- Whole Home Approach – Homeowners may be motivated to purchase a heat pump as a carbon reduction option for their home, but this may not be the most appropriate solution to address their home performance issues. Home renovations should focus on envelope first approaches and whole home solutions for energy retrofits to ensure heat pumps are properly sized and appropriately selected for retrofit applications.
- Electrical Panel/Service – Policy shifts towards efficient electrification creates challenges to accommodate electric needs especially in existing homes with 60A and 100A service.
DUAL FUEL HEAT PUMP
BACKGROUND: High capital cost and potential increase in operating cost of heat pump system are still the two most significant barriers to full electrification of HVAC systems for homeowners. However, dual-fuel technology, if properly operated, has the potential for home heating/cooling costs to be competitive and at the same time it also contributes to GHG reduction.
METHODOLOGY: Challenges, opportunities, best practices, and applicability of various existing and developing dual fuel technologies have been identified through literature review/online research and interviews with industry professionals. To compare the impact of different mechanical systems of varying fuel types on various energy-related factors, including energy consumption, GHG emissions, and energy cost, a simulated case study of two (2) existing Vancouver homes was also completed using HOT2000 energy modelling software.
KEY FINIDINGS FROM SIMULATED CASE STUDY:
- Adopted control strategy is a key element to influence the performance of dual-fuel heat pumps. The simulated results showed that dual fuel system used significantly less gas energy, and hence, produced less GHGs when the heat pump balance point was utilized as opposed to the 5°C cut-off temperature for the switch-over point.
- Performance of a heat pump is strongly influenced by the required heat loads and sizing of the appliance. Therefore, the whole home/envelope upgrade first approach and proper load calculations are the two critical factors to maximize the financial and environmental benefits.
- Dual-fuel system may work best as a displacement option when:
- Space heating load is large to be fully met by heat pump capacity and the operating cost is a concern
- Existing envelope performance is poor but the envelop upgrade is not a current option.
Ecolighten is pleased to support the City of Vancouver with the air-to-water and dual fuel heat pump retrofit projects. As a sneak peek, we’re also currently working on the ‘Zero Emissions Pool Guide’ with CoV and planning to issue the document early next year. Please stay tuned!
To learn more about any of our past projects, please contact Ecolighten at 604-971-2088 or [email protected].