SUSTAINABILITY Can a ground source heat pump provide hot water?
I’m planning a major renovation of my converted barn. My plan is to add a ground source heat pump (GSHP) but can’t find any information as to whether these can supply domestic hot water (DHW). If this is possible, is this an efficient way of achieving a hot water supply? Would it need a bulky storage tank? Are separate dedicated hot water supply systems preferable?
Yes, ground source heat pumps can and normally do provide DHW. They run slightly less efficiently when delivering hot water, as you need to raise the temperature to a higher level than with space heating. However, they still fare far better (by a factor of about 2.5) than when using something like an immersion heater. Don’t forget to install a solar water heater, too; these are low tech, many are made in the UK, and they will fulfil about 50% of your hot water need. They’re also relatively cheap if you’re effectively building from new. For more on GSHPs see my article on page 75.