Heat Emmiter Design
The importance of correctly sized heat emmitters (radiators / under floor heating)
Most people are aware that underfloor heating works exceptionally well when paired with a heat pump but one of the most common questions we are asked is…
‘can radiators work with heat pumps?’
Well the simple answer is yes they can. But…
Traditionally radiators were designed to work with boilers which merrily sent hot water to them at typically 60–70°C. Whereas, modern heating systems such as heat pumps typically send water to the radiators at 40–50°C, this is usually referred to as a low temperature system. For the heat pump to warm your home up and keep it warm it needs bigger radiators. But…
It may be, that your existing radiators are already bigger than they need to be to work with a high temperature system and would therefore work just fine with a low temperature heat pump. How can this be possible ? Well if your home was built in the 60’s, 70’s 80’s and even the 90’s at the point it was built it probably would have had poor insulation levels when compared with insulation levels used today. The radiators installed would have most likely have been sized against a number of parameters:-
A rule of thumb best guess what the room might need
A thought about what would look right in the room
And what did the plumbers’ merchants have in stock at the time
If in doubt install a bigger one
Hardly scientific but that methodology worked well enough. But since your house was built and the plumber installed radiators, you have probably added more loft insulation, you may have had cavity wall insulation fitted, you may well have installed new windows, all of these improvements will have reduced the heat load from when the house was first built and so you may find having reviewed the building heat losses that some or all of your radiators may be large enough.
The only way to be certain is to review the size and output of each radiator and compare that with the room heat load, the last thing you want is a new boiler or heat pump that cannot get your home warm because the radiators are not the right size.
What Include in This Service
We will review the existing type and size of radiators installed in your home and then estimate the likely output capacity of these in watts and BTU’s at standard boiler temperatures and again at low temperature heating parameters. Then we compare them against calculated room heat load to establish which if any need to be replaced based on the output capacity.
If you are installing a whole new heating system as in the case of a new build or extensions, we will compare the catalogue outputs of the radiator styles you like against the likely capacity when paired to a low heating system.
It can be a little more difficult to establish the heat output capacity of existing under floor heating (UFH) systems but there are ways, which we are happy to discuss with you.