This sheltered housing development, managed by Castle Rock Edinvar Housing Association, consists of 28 flats which were built in 1989. The existing heating was supplied from a central boiler house, providing each flats hot water requirement through individual electric immersion heaters installed in every flat. The elderly tenants were finding the running costs for heating and hot water increasingly expensive.

We were asked to provide a comprehensive solution to the problems of the inefficient and old boiler system and to the increased fuel costs experienced by the tenants.

In partnership with Worcester Bosch Commercial Design Department, two new Buderus GB312 100KW condensing boilers were installed, as well as, solar thermal collectors on the roof. The system is designed to make use of any solar gain, from the solar panels, collected in the form of hot water in a large ‘Buffer Tank’ situated in the central boiler house. When enough hot water is collected, it is passed into the heating or hot water circuits, bypassing the condensing boilers, saving the need to heat the system with the new boilers.

To increase efficiency in each of the flats, the existing hot water cylinders and immersion heaters were removed and a ‘˜Hot Box Unit’ was installed. This uses the hot water from the communal heating system to heat domestic water and as well as the radiators in the flats. In addition to giving efficient instantaneous hot water, the ‘Hot Box Unit’ also measures the energy being used and communicates this information back via a WiFi connection in the building to the Housing Association who are able to monitor energy used and bill each flat individually.

Mark Milne, Director of T.B. Mackay, commented “the innovative combination of high efficiency gas boilers and the array of thermal solar collectors on the roof, combine to offer an efficient and sustainable heating and hot water system, not only benefiting the environment but also reducing the heating fuel costs for the residents at Letham Gardens. It is a pleasure to work with our clients Castle Rock Edinvar Housing Association”.

The entire project coordination was handled in-house by T.B. Mackay Energy Services, from our design team, through to installers and controls electricians.