Elson CB Si units in each apartment use hot water from central plant, to heat a store of water from which underfloor heating and mains-pressure hot water can be provided. These units could be regarded as combi boilers fuelled by hot water generated by central plant and give users the same time and temperature control as they would have with their own boiler.
Energy use is metered so that householders are charged for the energy they actually use.
Similar units have also been installed in the refurbishment of Hawthorne Mills, a social-housing complex in Leeds dating from the 1980s.
Centralised heating and hot-water services were provided by hot water at 85°C through pipes running through each flat. These pipes were hot all year round, leading to indoor temperatures as high as 40°C in the summer.
Pipe runs are now confined to corridors, and Elson units provide the interface between the central plant and services in each flat. Energy costs of £7500 a year are expected to be reduced by 20%. Honeywell Smartfit controllers have been installed in each flat.
