Air source heat pump for radiators

[eurocooling]

Hello can any one tell me what the best systems to do just radiators off a air source
Heat pump can we just use a heat pump to heat them up as the maximum distance is 30m from outdoor unit we need to do 11 rads and the pipework is already pre
Installed

[Bigfreeze]

Heatpumps aren't suited to radiators as the temp required is too high. If you have a very well insulated house and can manage to heat the house with 40C or less going through the rads then I would look at a different technology to heat the house.

[cooper3305]

You can use radiator however the surface area has to be bigger...... in other words get bigger rads. To use low grade heat temps your property needs to be super insulated otherwise the COP and cost saving's you were expecting will be non-existent. I have commissioned a clivet air source unit as part of a district heating system that was the UK'S first zero carbon homes. so I would end on this note; its possible. but get all the facts and figures first. renewable's are great until you miss- calculate the heat load needed.

[AlexG]

Eurocooling, some manufacturers produce heat pumps with up to +65C hot water. So i suppose you can use heatpump. Good luck.

[eurocooling]

Alex I see daikin Altherma do one a high and low temp ones so I will try that one plus as its only doing the rads it will be straight on to the pipework never install one don,t know if any one has the installation manuels of one.

[eurocooling]

Another question someone can help can install the daikin heat pump straight to the return and flow pipes, does it need any tanks adding to this as this system as it is only trying to do the rads

[AlexG]

You can consult in your local Daikin office. Also you can check Climaveneta or CIAT.

[install monkey]

robur- gas fired 170% efficient
http://www.robur.com/products/e3-systems/

[woolyback]

Please be careful, any heat pump can heat radiators, the radiators will need to be sized to mean water temperature produced by the heating source, with this in mind the lower the water temperature the more energy efficient the system will become (even condensing boilers but that’s another story). There are problems with radiators at very low water temperatures but in theory you could have a mean water temperature of 30 degrees (the radiator could be the size of the wall but possible). If you intend to use the existing radiators and pipe work then please consider what mean water (flow to make it simple) temperature is being used at present to heat the property. Question; can any insulation updates be done to the property if so re-calculate the heat loss and re-calculate what mean water temperature you will require to heat the space. If you can keep the flow temperature below 45 degrees with weather compensation, on a low temperature system the running cost should be cheaper or on par with a Gas boiler. Another choice is that the high temperature system could be selected, this can supply a flow temperature up to 80 degrees. Just keep in mind the lower the water flow temperature the more energy efficient the system will become.
Connecting to an existing system has more problems, can the water pump in the system overcome the static resistance of the heating system (the high temperature system has a good pump and with most systems I’ve seen using 22mm copper pipe with 15mm stabbed in rads there is generally no problem with either system but please be careful with that information).

To find out the output of a radiator measure it and look at the technical information from the manufacturer, normally they also have a correction factor table, depending on the manufactory they use a room temp of 20 degrees and the mean water temp higher in so many degrees. silly example, correction factor for mean water temp of 5 degrees (5 degrees higher than the room temp water flow temperature of approximately 28 degrees) 0.05 and you require 500watts to heat the room you dived this figure by the correction factor, so 500 / 0.05 = 10,000watts, with this you now select your impossible size rad to give you 10kW to heat the space that requires 500watts (super-efficient system though). Hence why under floor heating (done right) can be very efficient.