As bpratt mentioned, you haven't told us your location. This will effect your heating requirements, as will your houses design (orientation & insulation levels). Your location will also effect the cost of different energy sources, particularly gas.
If your heating requirements are quite low underfloor heating may be overkill. It's expensive to install, & has slow reaction times. For colder climates though, it would be lovely, toasty toes! And as there's no forced air it can be more comfortable, particularly for allergy sufferers.
I wouldn't recommend electric underfloor heating. Due to the high cost of electricity it can be very expensive to run. Electric radiant heating (such as electric underfloor) will only produce a maximum of 1kW heat energy, for each 1kW of electricity used. Conversly, electric heat pumps (such as RC air con) are much more efficient, & can produce 2, 3, or even 4kW (for warmer outdoor temperatures) of heat per kW of electricity.
If you do decide to go down the underfloor route, I'd recommend hydronic (hot water), heated by either a condensing gas boiler, or a heat pump. Hydronic heating can be used in radiator panels, not just for underfloor. Note, these are all costly installs, particularly in Australia, where they're not so common.
As mentioned, gas ducted can be quite cheap to install, with reasonable running costs, although these are expected to increase. Also note that any ducted system will face efficiency losses, of up to 30%.
Will you also require cooling? Heat pumps (reverse cycle air conditioning) can be very efficient to heat with. Note, if you're in a cold climate be careful which heat pump you choose. Some units will freeze up in cold weather, & run an inefficient resistance element to defrost it. Other units will run efficiently well below freezing.
If you decide to go the heat pump route, & are happy with a couple of heat point sources instead of ducting, you could choose ductless mini-splits. These are extremely efficient to run. They have one outdoor unit, connected to multiple indoor units. Instead of ducting warm air (with efficiency losses), these use refrigerant between the outdoor & indoor units. Depending on the design, & the number of indoor units you choose, these can be quite costly to install.
Statistics: Posted by ddarroch — Jul 24, 2014 3:55 am