Median Care Home, Hackney, London

System Overview

The heating system is based on two Hercules 85 Air Source Heat Pumps (ASHPs), connected to a 2,400-litre buffer tank that stores water at an average temperature of 70°C. The ASHP installation is hydraulically separated from the existing Low Temperature Hot Water (LTHW) building heating circuit via a plate heat exchanger.

The existing LTHW system operates as a variable temperature heating system with a 55°C flow and 45°C return temperature.

To optimise running costs and system efficiency, the ASHPs operate between 2:00am and 6:00am, utilising off-peak electricity tariffs to pre-heat the buffer tank in preparation for the building’s heating demand starting at 7:00am.

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Domestic Hot Water (DHW) Provision

Domestic hot water is supplied by an Athena 500L hot water storage heat pump, an all-in-one system designed to deliver a continuous supply of 60°C hot water for immediate use.

The unit features intelligent onboard controls and includes four 3kW immersion heaters for additional heating capacity during peak winter demand. These immersions can be operated in hybrid mode to supplement the heat pump, ensuring maximum efficiency and consistent hot water availability.