Supermarket cooling provides heat source for domestic hot water
The first supermarket to be built to PassivHaus standards in the British Isles includes a Dimplex ground-source heat pump that draws energy from refrigeration and cooling systems to supply domestic hot water. The Tesco store in Tramore, County Waterford, is built to very high levels of air tightness and insulation, so water heating is an important consideration in the overall performance of the building. Such buildings typically have an annual energy consumption less than 15 kWh/m2.
The DHW system was designed by Dimplex and Dynamic Energy Solutions and installed by Geothermal Solar of County Kildare. It easily meets the total hot-water requirement for the store — including staff canteen and washrooms, and customer washrooms.
The Dimplex high-temperature ground-source heat pump can deliver flow temperatures up to 70°C. Typical source temperatures from the cooling system are 25 to 28°C, so the heat pump can easily deliver flow temperatures of 60 to 65°C with a COP of about 4. The heat pump was part of a complete pre-assembled plant room that was delivered to site to be plumbed in.
Fergal McEntee of Dynamic says, ‘This application looks at the energy requirements for supermarkets and has opened the business community’s eyes to the possibilities for heat pumps, particularly with regard to using them to provide hot water. As a result of this installation, we are now talking to commercial clients in a wide variety of sectors.’
