Housing charity selects air-source heat pumps
Mitsubishi Electric Ecodan CAHV monobloc air-source heat-pump boilers have been installed to provide heating and hot water for new flats built by the St Mungo’s charity in Lewisham. Among the project’s requirements were the need to deal with the different heating requirements of this community heating scheme and deal effectively with regular changes in tenancy and occupied hours. Tenants can also control the temperature in their own flats, while St Mungo’s has full central control of the system.
Waterstone Design designed the system, which comprised three heat-pump boilers that can deliver 130 kW with an ambient of -3°C. The drop off is minimal right down to -20°C, including defrost. They provide underfloor heating for all 24 dwellings and DHW via a direct hot-water plate heat exchanger to ensure operating temperature can be kept as low as possible.
The installation can deliver heat in 500 W increments from 18 kW upwards. The units cascade on and off to achieve peak efficiency and ensure even wear and tear during their operating life. Each unit has two separate refrigerant circuits, guaranteeing 50% backup.