A preliminary study of window opening in 18 low energy houses.

An energy efficiency monitoring programme was carried out from 1984 to 1986 by the South London Consortium Energy Group, United Kingdom Department of Energy, with assistance from British Gas, Watson House, as part of a demonstration project funded by the United Kingdom Department of Energy, the EEC and SLC Energy Group. 18 occupied low energy houses were thoroughly instrumented in order to monitor energy usage and occupant hehaviour. Data collected included temperatues in each room of the house, window usage determined from microswitches on every openable window, individual energy consumptions for heating, hot water, cooking and electrical appliances, and detailed weather monitoring. Humidity measurements and ventilation tests were also performed. Pata was stored as hourly averages of 2-second readings over the entire monitoring period. This enables a comparison to be made between window opening patterns of occupants recorded on daily, weekly and seasonal timescales. These window opening patterns are discussed with respect to the levels of occupancy, building energy consumption, occupant activity , comfort, perceived need for ventilation , and external weather conditions. The discussion of these preliminary results leads to a critical assessment of the installed warm air heating and supply ventilating system, and the differing reactions of some occupants to energy conservation and air quality. Suggestions are made concerning changes in system design to maximise the air quality within the building whilst minimising ventilation heat losses for differing levels of occupancy. The data collected reinforces the established criteria for window opening behaviour. The detailed level of data collected should, on more thorough analysis, provide a further contribution to these criteria , as indicated in the text.