A Breath Of Fresh Air For Social Housing Heating System
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A ground breaking pilot scheme using Air Source Heat Pumps to provide heating and domestic hot water has been installed in a social housing property in Leeds thanks to cooperation between HEAT, Marstair and Gledhill Water Storage. Gledhill's BoilerMate HP - Woman With Towel Next To Excercise Bike
The wet heating system in a bungalow in Warren Lane, Arthington, utilises Gledhill’s BoilerMate HP, a unique thermal storage appliance that captures the renewable energy created by an Air Source Heat Pump (ASHP) to provide ultra efficient heating and hot water.

The combination of an 8kW Marstair BWarm ASHP and the Gledhill BoilerMate HP thermal store provides a sufficient supply of heating AND hot water. Previously this has proved impractical because the low flow temperature of 50°C from an ASHP prevents the reach of satisfactory hot water temperatures with any viable flow rate. It is also important to maintain a low return temperature that will allow the ASHP to run for extended periods.

Gledhill’s BoilerMate HP has an innovative twin tank construction that overcomes both these issues. Its thermal store delivers heating and supplies a secondary unvented cylinder with domestic hot water with a pre-heat capability of 50°C. It is then possible to boost the domestic hot water to a set temperature of 60°C using direct electrical heating at off-peak tariffs to prevent legionella.

The thermal store’s intelligent microprocessor monitors the heating demands of the home and ensures that low cost heat pump energy is called upon first, initiating an electricity top-up when input from the heat pump is not sufficient to meet demand.

The property had been previously run on Economy 7 heaters coupled with a solid fuel stove which were both inefficient and costly, and plans to install a natural High Efficiency boiler with full central heating were scuppered upon discovering the house is outside the Transco licensed gas area.

An ASHP uses similar technology to that employed in domestic refrigerators. It is an electrically powered appliance consisting of a compressor, a carefully matched operator coil and heat exchanger, and is designed to provide heating by extracting heat from outside air. Typically the heat passed into the property will be three times the energy used by the compressor and fan delivering a Coefficient of Performance of 3.

The carbon emission is thus reduced from 0.422kg/kWh (SAP2005 value for grid electricity) to 0.14kg/kWh, a figure less than gas (0.194kg/kWh).

The pilot scheme, which is being coordinated by Leeds City Council and Leeds North West Homes (LNWH), is the first of its kind combining ASHP and thermal storage, and forms part of LNWH’s plans to look at alternative heat sources and technologies in order to reduce carbon emissions and provide an economical means of heating for tenants.

There are currently a large number of electrically heated multi-occupancy high-rise dwellings in need of a viable replacement heating system. An ASHP can be used at any elevation, requires minimum maintenance and when combined with Gledhill’s BoilerMate HP can prove both cost effective and extremely energy efficient.