Bivalent systems with inverter driven heat pumps
Electricity is the energy of the future. Wherever possible we should be striving to displace fossil fuels. Incremental improvements are being made to the electric grid to meet the requirements of electric vehicles will also help ensure that we achieve the decarbonisation of heat by 2050.
However, that said there remain some areas of unevenness in this progress. There are places where the electric supply remains weak and the costs of upgrading are prohibitive. Where this is the case and where large and old properties in particular create high demand for heat, there is still a role for bivalent systems as a step towards the final aim of a complete transition from fossil fuels.
Manufacturers of heat pumps increasingly package them to make whole self-contained systems that have guaranteed component compatibility and are simple to replicate time after time. This does mean, of course, that every pack is not always going to be suitable for more unusual installations such as bivalent systems.
To assist you to ascertain which heat pumps are compatible with a bivalent system here’s a useful table of our heat pumps and components so that you can see at a glance which can be used in a bivalent system.
|Heat pump model||Boiler integration possible?||Reason (if no)|
|WPE-I 230 H||Yes|
|WPE-I 230 HW||No||Integrated hot water tank - not suitable for connection to boiler|
|WPF .. S||No||Controller version not compatible with boilers|
|WPC .. S||No||Controller version not compatible with boilers|
|WPL-A with wall mounted WPM||Yes|
|WPL-A with HSBB, SBP||No||Integrated hot water tank - not suitable for connection to boiler|
|WPL-A with HSBC||No||Integrated hot water tank - not suitable for connection to boiler|
|WPL 25 with wall mounted WPM||Yes|
|WPL 25 with HSBB, HSBC||No||Integrated hot water tank - not suitable for connection to boiler|
|WPL.. Classic with HM Trend||Yes|
|WPL.. Classic with HSBB, HSBC||No||Integrated hot water tank - not suitable for connection to boiler|
It is important to understand that our WPM heat pump controller prioritises the use of the heatpump and will only ever draw on the boiler as a last resort. Indeed, if you have a system which also includes PV panels, the WPM will also prioritise the use of these before using the boiler.
We always advise that before you buy your heatpump system you gather as much information as possible on the existing boiler. Dependent on the make and type boilers can be controlled with a simple enable switch or one of two options can be used to modulate the output of the boiler (a 0-10V signal or a PWM signal). We can provide information on the best options If you call us to discuss your needs during the design phase of the system. An early call to our specification and technical teams is strongly advised with these systems to ensure that important considerations are met early on in the project whilst it is still easy to make accommodations.
If you are planning a hybrid system, we do also always recommend a buffer tank or some method of hydraulic separation. This will almost certainly mean more space is required than a typical heat-pump-only installation for plant such as water storage and controls.