This project will address the challenge of providing domestic hot water (DHW) using low carbon heat pump technology given the overwhelming trend away from conventional hot water tanks in homes and the inability of present heat pumps to provide instant hot water.

We will develop a suite of heat pump / storage / control technologies, using either electricity or gas that function without conventional storage cylinders and can deliver energy efficient affordable hot water to a wide range of dwellings well into the future.

The University of Ulster will use a novel compressor being developed by industrial partner Emerson that has an exceptional range of running speeds, enabling the same device to either deliver e.g. 25 kW for instantaneous hot water or 10 kW or less for space heating. This would be used in conjunction with a small buffer store to overcome the delay in start-up before hot water is available.

Present gas fired heat pumps (both commercial and under development at Warwick) are easier to modulate but are physically large if delivering 20 or 30 kW and also have a long start up time (5 minutes). The Warwick goal is to use new composite adsorbent heat exchangers to reduce start up time to one minute, even when meeting a 25 kW load and to reduce key component sizes to achieve a compact system.

Thermal storage is a vital part of DHW provision by heat pumps. A small buffer store may be needed to overcome starting transients, or a large capacity store might be needed to provide a bath-full of water quickly. An intermediate capacity store might work together with a heat pump to meet peak loads. Our research will encompass buffers, compact PCM stores that could be sited in unused spaces such as corners in kitchens and 'flat' stores using vacuum or aerogel insulation that could fit under kitchen cabinets or other available unused spaces.

Industrial partners: Emerson Climate Technologies GmbH, Spirax Sarco, Baxi Group.

Principle Investigator:

Professor Bob Critoph

Co-Investigator:

Dr Stan Shire

Value: £1.24m

Start date: 01/03/2016

End date: 30/11/2019