Abstract

The environmental impact of residential buildings has been demonstrated to be significant, and to be a result of both their construction and operation. This study therefore looks at the best strategies to minimize life cycle energy consumption (LCE), as well as cost (LCC), for a single-family house in Quebec.
First, an optimization model for the envelope is built, and includes a detailed TRNSYS simulation which computes the operation energy use, embodied energy of material and cost data. It is coupled to GenOpt, a general optimization program, to find the minimum LCC and LCE values, using a Particle Swarm Optimization algorithm. The optimal envelopes and a code compliant envelope are then modeled with various combinations of space conditioning and domestic hot water systems, to evaluate the impact of energy efficient mechanical systems on cost and energy.
It is shown that energy efficient mechanical systems are a better investment than envelope efficiency measures, from a LCC perspective. The optimal combination found is a minimal code compliant envelope with a ground-source heat pump and a desuperheater. These research results suggest that future building code improvements should also cover in detail the performance of mechanical systems, instead of focusing mostly on envelope characteristics.