UPDATED: Air Source Heat Pumps/Air Con - Full Info & Guide, is it cheaper to run than mains gas?

richardc1983 wrote: »

First question for you: Is there gas to the property? If there is then gas central heating is your better option unless you want air conditioning also. Gas per KW unit is still cheaper in the UK than a KW of electricity and on a modern efficient boiler is therefore going to give you cheaper heating than an air source heat pump. I'm a pro air con but I know from having air con in my house its still cheaper to heat the house with the gas boiler and radiators. I wouldn't be without the air con though.

To answer your other questions, Fan convector's vs radiators: Fan convector's or otherwise known as fan coil units you will have a quick heat up of the building as the system is using warm air to heat so you have quick response times. You also then benefit from being able to use lower flow temps (although you could install fan convector's with a gas boiler and achieve the same) which overall make it more efficient.

The disadvantages are that there is no residual heat so once the room reaches temp and the fan coil switches at thermostat there will be no slow heat released like there is from radiators. Some people also prefer radiators as they are often positioned under windows and this helps alleviate draughts from the window (tip if you do go this route make sure your rads or fan coils are positioned under windows). Radiators give out radiant heat which is the same as being sat in front of a fire or being in the sun, this generally can be a more pleasant heat to some people. There's usually less to go wrong on a radiator than a convector, no filters to service and no fan motors to fail or coils to clean. However you will lose cooling and personally I have both, I have a multi split air con system which provides cooling in the summer and in spring/autumn where I don't want to heat the house I use it on heat to heat the room I am occupying. Then when I am heating the whole house on goes the gas boiler I do occasionally use the air con also to boost the temp of certain rooms if its very cold as supplementary heating.

The key to energy savings is to run your flow temp as low as you can so the rads are barely warm. You oversize radiators to achieve this on a heat pump. The other 3rd option is underfloor heating which must use low flow temps by design, these systems are slow to respond as your heating the floor slab which then in turn heats the space. This gives a very even heat distribution in the room you dont get hot or cold spots, the disadvantages are that the system must be left on all the time in winter and its slow to respond so if it becomes hot or in spring summer it takes a while to stabilise if your turning the system off and thus back on if you have a cold snap. But this is regulated with zone controls.

richardc1983 wrote: »

Considering all points your going to need some form of cooling so I would just go with an air conditioning heat pump system. So you could look at a multi split system where you have several indoor units connected to one outdoor unit, the only thing with these are all indoor units have to be on the same mode either heating or cooling but you can have individual room set points so bedroom at 21 and lounge at 23 etc. There is also a VRV or VRF systems available that connect to one outdoor unit via fan coils and you can have the flexibility to have different operation modes in diff rooms so your lounge could be at 23C cooling and your bedroom at 21C heating - the heat recovered from the lounge cooling is recycled and used to heat the bedroom.

In Spain and other Europe countries where Air Con is essential they use the air con to heat in winter as standard. So I would personally go for a multi split system or the more expensive VRV or VRF.