Techno–Economic Feasibility Study and Greenhouse Gas (GHG) Emission Analysis of Natural Gas Driven Heat Pump (GHP) Systems in Canada through Building Energy Simulation and Field Testing

This dissertation presents research on potential benefits of natural gas–fired heat pumps (GHPs) in Canadian climate, identified by conducting field evaluation, simulation and techno–economic feasibility analyses for two different types of natural gas driven heat pump systems, i.e., natural gas engine-driven heat pump (GEHP) and gas-fired absorption heat pump (GAHP). Since gas-fired heat pump is a newer concept in Canada, there is a lack of knowledge that was addressed by this research. Three different types of buildings were selected for this research to consider the future potential of installation of GHPs in different types of building. A GEHP was installed and commissioned in a warehouse/office in Woodstock, ON. This was used, along with a GAHP system installed at a library building in Tweed, ON, as case studies and provide information regarding the energy saving, energy cost savings and reduction in GHG emissions achieved by GHPs in Canadian climate. An additional GAHP system was installed and tested at the Archetype Sustainable House in Woodbridge, ON at Kortright Conservation Centre of Toronto and Region Conservation Authority (TRCA).

Results confirm that GHPs can be operated in Canadian climate with lower operational costs compared to conventional equipment while also providing a net reduction of GHG emissions especially when operated in heating mode as a replacement for conventional furnaces. However, when operated in both heating and cooling modes, to replace conventional furnaces and air conditioners, the benefits of GHPs greatly depend on the relative duration and severity of the heating and cooling seasons, marginal costs and GHG emission factors of both natural gas and electricity.

Heating and cooling degree days that result in highest energy savings were determined. Also, marginal cost of gas and GHG emission factor threshold up to which GHPs could yield benefits were also identified for various cities in Canada. Furthermore, it was found that imposition of carbon price alone would not be able to diminish the cost benefits of GHPs in the near future while any future GHG emission restrictions in some cities would affect the viability of GHPs at those locations.