Canadian low-energy housing: National energy context, and a case study of a demonstration house with focus on its ground-source heat pump

摘要

This article first reviews the energy use in Canadian houses and the current energy-saving practices. Various low-energy house (building) concepts are discussed, and some research projects and initiatives completed in Canada over the last 10-15years are then briefly outlined. Second, it describes the EcoTerra demonstration low-energy house and its innovative construction and HVAC system that integrates a reversible brine-to-air geothermal heat pump as a main heating and cooling system, electricity, and heat generation from a building integrated photovoltaic (PV)/thermal (BIPV/T) system, concrete floors and walls as passive and active solar energy storage means, and several heat recovery devices. The EcoTerra house was built in 2007 in the province of Quebec (eastern Canada) under the Equilibrium Housing Pilot Demonstration Project, a national initiative lead by Canada Mortgage and Housing Corporation that brought the private and public sectors together to develop low-energy healthy homes. This article summarizes the overall energy performance of EcoTerra's main energy system as well as the 5-year design validation and energy performance of the ground-source heat pump with vertical, closed-loop ground-coupled heat exchanger. The results obtained show the annual electrical energy consumption of EcoTerra has been reduced on average by 57.9 compared to the average consumption of Quebec's (eastern Canadian province) conventional houses heated with electrical baseboards. On the other hand, the ground-source heat pump (GSHP) has ran with relatively high heating and cooling performances while the ground thermal capacity has been well-balanced and fully recovered from one heating dominated season to another.