Heat pumps, the unsung hero of the energy world, are mechanical devices that can harvest renewable thermal energy for space heating and cooling. They’ve been identified globally as a key solution to building and retrofitting low-carbon buildings, and they help consumers save on energy bills. So why aren’t we seeing wider adoption of heat pumps in buildings? In Asia and Europe, heat pumps are commonplace. But in Canada, other electric and natural gas powered systems have dominated the HVAC landscape. This is mostly due to the high up front cost and availability of cheap natural gas, lack of familiarity with the technology, and skepticism about performance in a cold climate.
As part of Ontario’s Climate Change Action Plan, the provincial government has promised to provide financial incentives for residential heat pumps as early as winter 2017. Since heat pumps offer significant GHG reduction potential, they will play a vital role in helping Ontario reach our GHG reduction target of 37% reduction by 2030. With government incentives coming soon, it’s important for consumers to learn about their options and factors to consider ahead of time so the government’s offering will result in savvy decisions, happy homeowners, increased faith in the technology, and positive conservation results.
Choosing a heat pump solution is heavily context specific (as is choosing any HVAC system). A building’s space heating and cooling needs are significantly affected by its design, location and spatial configuration, construction materials, and mechanical systems. While all types of heat pumps have the potential to conserve energy, the characteristics of a building can affect which option makes the most technical and financial sense.
Below are some great heat pump options that can assist Ontario in reducing its carbon footprint for space heating and cooling (this is not an exhaustive list):
What’s here NOW:
- (Gas) ABSORPTION HEAT PUMPS Absorption heat pumps are driven by thermal energy delivered via steam or combustion instead of mechanical (electricity). See our previous blog on Gas Absorption Heat Pumps
- AIR-SOURCE HEAT PUMPS Air-source heat pumps harvest low-grade heat from outside or expel heat outside. Recent developments have made these heat pumps more suited to a cold climate, and some are now efficient beyond -25°C.
- GROUND-SOURCE HEAT PUMPS Ground source heat pumps extract heat from the ground in the winter and expel heat to the ground during the summer. A key feature of GSHPs is their efficiency year-round due to ground temperature regulation. The in-ground equipment also lasts a long time – upwards of 50 years, lowering maintenance costs.
- HYBRID HEAT PUMP ARRAYS Hybrid heat pump systems combine multiple thermal energy sources or sinks to reduce costs and achieve higher efficiencies when a single thermal source is insufficient. Typically, this means supplementing electric heat pumps with a gas furnace or boiler system and cooling tower. You can also use multiple renewable energy sources, like the air and ground, if it makes technical and financial sense.
- SURFACE(Ground) WATER HEAT PUMPS Surface water heat pumps are considered a type of ground source heat pump, which harvests or rejects heat at wells, rivers, ponds, lakes, oceans, etc. for heating and/or cooling.
- VARIABLE REFRIGERANT FLOW Variable refrigerant flow systems are comprised of refrigerant lines, an alternative to hydronic or duct distribution systems that travel throughout a building carrying thermal energy from air-source, ground-source, or water-source compressors to multiple indoor evaporators. Special control units adjust the flow of refrigerant between building areas allowing unique temperatures for different areas simultaneously.
- WATER SOURCE HEAT PUMP Water source heat pumps can supply thermal energy in multiple ways (e.g. boiler/cooling tower, ground-source, hybrid). They can provide zone-controlled heating/cooling using water loops. Water circulates, via the loop, to multiple distributed heat pumps located in different building zones and exchange energy between the water pipe to meet heating and cooling demand.
Broad adoption of heat pumps in Ontario will likely take some time. It would be useful for the province to frame a strategic adoption plan that acknowledges current and future technology. Ontario could expand financial support in the future to include systems like community/ district heat pump systems, sewer wastewater heat pumps, or solar assisted heat pump systems.
There are some fantastic heat pump options available now and exciting technology developments in the works. Ontario’s large cast of collaborating stakeholders are putting us on the right trajectory for widespread heat pump adoption.
TAF will continue to explore the barriers and opportunities to widespread heat pump uptake in Ontario as part of our greater mandate to support scalable GHG reduction solutions. See here for more information about TAF`s current work on heat pumps.