Went up to Eynsham to visit Ice Energy. I thought their name was an acronymn until I asked how they had drilled a bore hole in an industrial park to get their heat energy. They hadn’t. Instead they heated the offices from a block of ice in a tank wrapped in the heat transfer pipes of circulating glycol.
This works because there is still some heat energy even at zero degrees C. This is extracted and heated up by the compressor and even colder glycol is returned to keep the block of ice frozen.
Having got over the shock of heat from ice (actually I still can’t get my head around it), I went on to look at the works.
I really is like a fridge working in reverse, and not that much bigger. Power is needed for the mainly for the compressor and then for one pump to circulate the hot water and another for the glycol circulating through the underground pipes.
The whole assembly puts the water tank on top of the heat pump and adds pretty sophisticated controls based on a number of sensors. One important detail is that the system heats the water up to 60 degrees once a week to pasteurise the system in order to prevent legionnaires disease.
The tank is going to be an issue. It’s actually double, with a hot water supply in the centre surrounded by water for the radiators. That may mean in our case using a separate tank to get enough hot water – and this will cause a space problem in the boiler room.
The next step is to arrange a site survey to check everything, size the system and let us know what it is going to cost.