How To Choose Buffer Size Or Thermal Store

We’re often asked what size buffer or thermal store to use with our heat pumps. Whilst the ultimate decision rests with the system designer the table below gives a good starting point.

If you intend to use your heat pump to take advantage of grid flexibility or cheap power tariffs you may need a much larger buffer.

Buffers and thermal stores can be used to meet peak demands of short duration, e.g. a morning hot water demand, this can reduce the capacity of heat pump required.

If in doubt go big!