Power Consumption Comparison of Five Building Envelopes in the Northern Prairie Climate of Manitoba

The energy efficiency of a building depends on building envelope performance. The results presented in this paper are the first of a long-term building envelope research project at the Alternative Village at the University of Manitoba in Winnipeg, Manitoba, Canada. Five test buildings were constructed using the following systems: two wood frames with fiberglass batt insulation and dense pack cellulose, one polyurethane structural insulated panels (PUR SIP), and two with the Stay in place PVC concrete form building system using 102mm and 204mm of concrete externally insulated with 102mm of expanded polystyrene foam. All of the buildings had a common foundation and roof system with a footprint of 23.8 m². Blower door tests were conducted to determine air tightness. Each structure was heated with an electrical resistance heater and maintained at a constant internal temperature. The thermal gradient through the wall and power consumption were monitored. The study period discussed in this report represents the main heating season from October 2011 to April 2012 consisting of 209 days. Based on the power consumption, the PUR SIP consumed the least at 2498 kWh, while the 204 mm Stay in place PVC concrete form building used the most at 2898 kWh for the same time period. The thermal gradient through the cross section of the wood frame structures was compared through the cavity insulation and at the stud. It was found that the cellulose building provided better thermal resistance along the stud when compared to the fiberglass batt insulation.