Understanding Multi-residential Energy and Water End-use Load Profiles PDF Download

Author: Canada Mortgage and Housing Corporation. External Research Program
Publisher: CMHC
ISBN:
Category : Apartment houses
Languages : en
Pages : 25

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Book Description
Energy used in residential buildings is a major energy use in Canada (21% of all energy) and presumably in most areas in the Northern hemisphere. A substantial fraction of this energy (24%) is used in multi-residential buildings. However, very little attention has been given to examining the patterns of energy and water consumption, let alone how they can be improved. This report suggests that significant savings and improvements in the efficiency of multi-residential systems are achievable, and this could go a long way toward reducing energy usage and fulfilling Canadian Kyoto obligations. Watershed Technologies Inc. and OZZ Energy Solutions Inc. have been monitoring energy and water usage in multi-residential buildings in the Toronto area since 1996. The present analysis looks at detailed (hourly) gas and electricity loads in 34 buildings and water consumption in 21 buildings over a two-year period from May 2001 to April 2003. An earlier report by OZZ documented the different physical features of these buildings and presented an overall summary and a preliminary analysis of gas, electricity and water consumption data along with daily and seasonal summaries. A more detailed analysis is offered in the present report. A new model is developed which describes the building's energy consumption for cooling and heating more effectively than the traditional degree-day model. The new model quantifies not only the changes in energy load per unit change in temperature but also its effective thermal capacity, the heating system overhead and system response to other weather factors, namely wind, relative humidity and solar access. More than two fold differences in the energy per unit area or water used per apartment unit among the buildings are observed. A study of seasonal and daily variability suggests that at least a part of these differences in the building energy efficiency can be attributed to poor or complete lack of energy management in many of the buildings. The data also suggests that in-suite electric heating is 2.5 times more efficient than central gas heating systems in multi-residential buildings. The same appears true of in-suite air conditioning, when compared to centralized cooling systems.