U.K. commercial buildings have a reputation of being energy profligate, largely due to the prevalence of air conditioning. Most architects and HVAC designers only associate low energy consumption with summer cooling operation. However, the U.K. electricity utilities have peak maximum demands in winter, and buildings need to be designed for year-round low energy usage. Relatively few monitored studies of the total annual energy implications of exposed ceiling soffits and alternative ventilation strategies have been published. This paper reviews independently published performance data of low-energy buildings and the impact of the various fabric energy storage strategies now available. It demonstrates that low-energy mechanical ventilation systems incorporating efficient heat recovery and effective fabric energy storage have higher year-round comfort criteria and significantly lower prime energy consumption than natural ventilation strategies. Supplementary cooling and heating demands and consumption are shown to be minimal in such buildings for temperate maritime climates.

Units: SI