Many believe that heat pumps must be combined with underfloor heating because their temperature output doesn't match that of a gas boiler. However, this is not the case. Not only can you use them to power radiators, in many domestic cases you can use your existing ones.
While it's true that gas boilers can output very high temperatures, they generally run no higher than up to 65°C. Any hotter and radiators would pose a burn risk. Some heat pumps are actually capable of these temperatures, but tend to be relatively inefficient at these levels. Instead, they usually hover around 40 - 45°C to ensure that they offer good efficiency and adequate heating.
Many radiators found in UK homes are oversized for a gas boiler system, compared with the BTU output required to heat the room they're in. As a result, even if an air source heat pump outputs just 40°C, these oversized radiators are actually the right size for an air source heat pump.
Check out the rating you need here: BTU Calculator. You can check our specs there too, to see the outputs of each size and type.
Aluminium is the material of choice for radiators combined with heat pumps. Aluminium is an incredibly effective conductor, meaning radiators heat up very quickly and transmit their heat into the room faster than steel and far faster cast iron radiators.
More information on radiator materials here: Choosing a Radiator: Materials
Since the temperature of the water passing through the radiators will be lower with a heat pump than with a gas boiler, you must conduct as much of this heat as possible, as quick as possible. Aluminium is the perfect choice for this job.
It can also be recycled over and over without degrading. So, you could easily make your whole system more environmentally friendly, as well as more efficient, by buying radiators made from recycled aluminium. Since making the switch to a heat pump is about reducing our environmental impact, it makes sense to opt for the eco-friendly option when it comes to radiators for your air source heat pump.
If nothing else, it means the materials in your system can be recycled if you ever needed to replace it.