Integrated thermal energy storage extended to group heating applications.

Although the great majority of British dwellings are heated by individual gas systems, there are some instances, particularly in blocks of flats and retirement homes, where individual gas appliances cannot be specified. In these buildings the alternative to individual systems is a group heating scheme whereby a central boiler plant supplies hot water to each flat for heating and domestic hot water. In the past, group heating systems have not always been successful. Comparative results show that energy use of group heating systems is, on average, 50% higher than that of individual systems. There are two main reasons for the higher running costs. The first is the absence of heat metering. Effective heat metering is relatively costly and has not been widely adopted. As a consequence, there is no incentive for occupants to save energy, either in the heating of their dwelling or in the use of hot water. The second reason is the high distribution heat loss which con account for a significant proportion of the annual energy used. Recently there has been a resurgence of interest in group heating both for existing and new buildings, especially where individual gas systems are precluded.