Linking Energy to People in Order to Measure and Control

CIBSE Technical Symposium, DeMontfort University, Leicester UK
6th and 7th September 2011

When analysing the energy use of commercial buildings with a view to reducing building operating costs and reducing energy consumption the most common metric is kWh/m2. However, this metric does not provide an understanding as to how effectively a building is being utilised once it is occupied as energy consumption is not related to the people who are responsible for this consumption. This paper proposes a new metric, Wh/m2h, in which the conventional annual energy consumption metric, kWh/m2, is divided by total person hours. Total person hours is the total number of hours that all building users have spent in the building during the year in question. Also the relationship between measuring occupancy and controlling energy consuming systems is examined. If occupancy is measured in order to understand energy consumption then this knowledge can also be used to automatically turn on or off the energy consuming systems that are directly related to people.