Cost of hot air central heating

cepheus

I was amazed at the claims of this site which compares the cost of running radiator central heating with warm air gas central heating, the latter appears to cost typically 1/2 to 1/3 the price! Can anyone confirm this level of difference?

The only reason I can think of that might explain some of the difference is that more heat may be lost near to the radiator through the walls and window whereas hot air is usually ventilated through the internal walls.

Normal gas central heating, with radiators,
(including water heating)

in very cold weather 44p
in cold weather 23p
in mild weather 17p

Warm-air gas central heating (including water heating)

in very cold weather 16p
in cold weather 11p
in mild weather 5p

http://www.changeworks.org.uk/uploads/wat/Heating_Comparison.pdf

moonrakerz

I have a warm air system in my house; lots of people, both on this site and face-to-face, seem to take pity on me almost as though I have a log fire in the middle of the lounge and a hole in the roof to let the smoke out.

Most (All !) of these comments come from people who have never had a warm air system, and the usual red herrings are trotted out:- spread the dust, spread diseases, etc, etc - none of which are true.

I have owned four houses, two of which have had a warm air system. I can honestly say that if I was given the choice of two identical houses, one with radiators and one with warm air - I would take the warm air without a moment's thought.

Having said that - I am afraid I don't believe the figures you have shown !

I honestly think my system is cheaper to run than a radiator system, but to prove that would be nigh on impossible.
I have seen several websites which state quite categorically that warm air systems are very economical to run:
"Warm air units are central heating systems that do not contain any water (i.e. a dry system). Air is warmed directly by the gas as it passes through a simple heat exchanger and then circulated through ducts within the property. They are extremely economical to run and quick to warm up from cold."

Half to a third of the price - no ! 20% to 40% cheaper - maybe ?

cepheus

moonrakerz wrote: »

Half to a third of the price - no ! 20% to 40% cheaper - maybe ?

Yes this sounds more realistic. I used to lodge in a house with hot air ventilation, and noticed it needed cleaning less because the dust collect at the intake filter. One disadvantage was the lack of drying facilities for clothes, but perhaps this could be solved by having a series of rails above the hot outlet vent.

I think this sort of system has great potential for the future in conjunction with a heat pump.

moonrakerz

cepheus wrote: »

One disadvantage was the lack of drying facilities for clothes, but perhaps this could be solved by having a series of rails above the hot outlet vent.

Our vents on the ground floor are actually in the floor, so you just stand a clothes horse over the top of it.

cepheus wrote: »

I think this sort of system has great potential for the future in conjunction with a heat pump.

Sounds good !

motco

cepheus wrote: »

I think this sort of system has great potential for the future in conjunction with a heat pump.

I am looking at buying a bungalow in a gasless area and that has no heating beyond off-peak storage radiators. It has a lot of land around it and cries out for a ground source heat pump system. However, it also has beautiful parquet floors and I would be reluctant to rip them up to fit the ideal heating output devices for GSHP - underfloor heating. As a bungalow, it would easy to retrofit a warm-air system and obviously a warm air system fuelled via GSHP would be perfect. Does one exist? I don't know. :cool:

Ken68

A lot cheaper, surely, with Air Source Heat Pump. Noisier though.

McKneff

We have had a warm air system since we moved in 20 years ago (the original one died about 10 years ago at about 20 yeares old)
So we replaced it with the same sort of system.
I wouldnt have anything else, instant heat and there is also a cool air blower system for summer integrated.

Brilliant, even more so now I know its cheaper.

motco

Air source is cheaper to install but is less efficient, I gather. But it's the heat exchanger to deliver the heat into the house system that may not yet exist that I am interested in.

Cardew

motco wrote: »

Air source is cheaper to install but is less efficient, I gather. But it's the heat exchanger to deliver the heat into the house system that may not yet exist that I am interested in.

Not sure what you mean in that post.

You can have an ASHP supplying radiators and a hot water tank.

The Mitsubishi Ecodan is but one of many systems being marketed - try a Google.

Although GSHPs were always supposed to have the higher efficiency, the efficiency of ASHPs has increased considerably in recent times.

That said it is really difficult to get accurate comparisons as most of the figures are 'massaged' either by manufacturers or enthusiastic customers(I find it strange that having invested in a system, so many people have to exagerate savigs - perhaps to justify their purchase?)

I suspect that averaged over a year a good average COP* is 2.5 to 3.0.

* With a COP of, say, 3.0 you get the heat equivalent output of 3kWh for 1kWh input.

motco

Cardew, simply that my internet searchings suggest that GSHP is higher efficiency than ASHP. I am totally open to further advice though. I simply want the most efficient system in a gas free area - oil, solid fuel, whatever. But it seemed to me that whilst retrofitting underfloor was difficult in this particular property, ducted air would be easier. I'll choose the source - air or ground - when I establish the availability of a system that delivers warm air rather than warm water.