Heat Pump Systems, Cogeneration, High Performance Building, Life Cycle Cost Analysis, Cold Climate
With increased awareness on the importance and benefit of energy efficiency, building owners and designers are frequently confronted with the challenge of which mechanical system is most suitable to meet the building’s energy target needs. The decision making process is often aided through the use of building simulation tools; however this type of analysis is often considered costly and time consuming in particular when various mechanical systems need to be assessed. With Natural Resources Canada’s priorities on promoting the sustainability and economic development of Canada’s natural resources, this paper presents an analysis conducted on several standard and innovative mechanical systems to aid decision makers in the early building design stages to select a suitable system. The paper further illustrates the benefits of each system type often not known or misunderstood. Using TRNSYS, five system types are evaluated in a typical newly constructed high performance mid-rise apartment in two Canadian regions: Calgary and Montreal. The five systems selected for comparison include (1) a conventional mid-rise apartment heating and cooling system, (2) boiler/cooling tower water source heat pumps, (3) ground source heat pumps, (4) a cogeneration unit sized to meet the heating load of the building and (5) a cogeneration plus electric driven heat pump system. Heat pumps were selected for the benefit in upgrading and utilizing renewable energy sources and cogeneration for the conversion of natural gas to electricity. The analysis includes a 20 year life cycle cost including a sensitivity analysis on forecasted utility rates.