A heat pump requires a hot water cylinder that is Heat Pump compatible. Usually this means a high surface area coil. The reason for this is that as a heat pump works at a high flow rate with low temperature difference of 5 degrees, you need a high surface area to transfer the heat into the water, otherwise the heat pump won’t be able to do it’s job correctly.
If you have a relatively new hot water cylinder and cannot see the economic viability of replacing in order to install a heat pump. You can opt for a retrofit solution in the form of a plate heat exchanger. See diagram below (please note this is a simplified diagram to show the concept)
- Plate heat exchanger rated for heat pump.
- Insulation Jacket / Shell for the Plate Heat exchanger.
- Hot Water Recirculator pump
- Isolation valves & non-return valves as necessary.