Can I use radiators with an air source heat pump?

Can I use radiators with an air source heat pump?

The simple answer to this question is YES.

But the existing radiators will most probably need to be up sized for the new low flow temperatures your heat pump will be set to. The lower this set point, the more efficient your heat pump will be, and therefore the cheaper to run. The disadvantage of lower flow temperatures is, however, that the lower the water temperature, the more radiating surface area you need to emit the same amount of heat.

So if you currently have a Gas fired boiler powering your heating system, with flow temperatures of 80C, and you exchange that boiler for a heat pump with flow temperatures of 50C, you will need radiators double the size, or double panel radiators where you currently have single panel radiators, or two radiators in a room where you currently have one.

You will often hear that underfloor heating should be the only type of heat emitter you consider when using heat pumps. The fact that underfloor system can work very well with flow temperatures as low as 35C do make them an ideal partner for heat pumps. If, however, you have an old property it may be impractical to install an underfloor heating system, and in many cases correctly sized radiators are the only practical option.

The other question people often ask if swapping out a gas boiler for a heat pump is – “Can I use my existing radiators”?

Your existing radiators can be used, but as explained above they might be too small, in which case you might need to add additional radiators into the system. Your will also need to ensure that your system has been thoroughly cleaned, to make sure that suspended particles in the system do not clog up the filter thats installed with the new heat pump to protect the heat exchanger in your heat pump from getting blocked.