underfloor heating - running costs

[g]

Hi,

I have always been an avid supporter of underfloor heating -- I don't know anyone personally to have any complaints about them. However in telling people here in Ireland that we installed it in a stone house we are renovating, almost everybody is "appalled" and skeptical. They tell us stories of people who have them installed and get them ripped out soon afterwards because of the gas guzzling/high heating costs. I can only think that in these bad experiences, the insulation under the floor and on the walls is improperly done, but they insist that this possibility is unlikely and that underfloor heating is an inherently disastrous heating method. But I don't see how something that is so successful and common elsewhere remains so successful if that is the case. I'm tired of defending the choice we made with the heating :-(

Anybody have ideas on the possible sources of bad experiences/high running costs with underfloor heating?

Thanks, g

[Peter Parry]

Electric underfloor heating quite rightly got a bad name for cost and poor installation as it was a favourite in a number of council built houses in the 60's and, in true council fashion, was badly designed and installed.

The experience with water systems is, as you say quite the reverse. On a sample of 1 my neighbour and I have identically sized houses built to more or less the same design and the same insulation standards 10 years ago. Both were self build - he installed conventional heating I used underfloor. Both use mains gas. The pattern of occupation of both houses is similar but the heating costs for mine are consistently 15-20% less than his.

[Alan]

In message , Peter Parry wrote

But surely no meaningful conclusion can be drawn from a sample of 2. I have friends that want their house heated to temperatures that I find uncomfortable - their house temperature may be only a few degrees higher.

I know of some people that have tuned on the heating for short periods to 'take the chill off' in the last week. My heating is still off.

[IMM]

Not correct. Most were in private homes. If gas is available councils always went for gas fired heating as it is 1/4 of the price of electricity to run.

[IMM]

In this months Selfbuild and Design mag there is an article on heating systems by an eco expert. Underfloor heating was ruled out in poorly insulted houses (which may be the case in Ireland) and only deemed suitable in homes with, or just above, current building regs insulation levels. High insulation levels were better suited to forced air heat recovery ventilation systems.

The design of UFH has to be right, with no cold spots in the floors, "high" insulation under the floors and "very" good control. A condensing boiler is now virtually mandatory for economy. If all points are not right then it may be a disaster.

[Peter Parry]

According to the BRI 80% of electric underfloor installations were in public housing. During the Wilson Callaghan era there was a policy of installing oil, gas and electricity in equal mixes in public housing, the cheapest fuels were electricity and oil.

Not then.

[IMM]

electricity

Gas has always been cheaper than electricity; in the past 40 years anyway. My UFH electric system was in private house and I knew of few in public housing. Public housing was going all warm air.

[Peter Parry]

No it hasn't, oil has quite often been cheaper and in the 60's/70's off peak electricity was cheaper at times.

Quite possibly, but your knowledge and reality are often a long way apart.

[The Natural Philosopher]

With decent insulation and a wet system - i.e. not electric - its pretty close to a conventional system.

What I find is that teh longer delays mean it spends a fair time warming up and colling down, and this represents a little bit of heat you probably wouldn't have used if it came yup to temp faater.

Do a decent insulation job and go for it. If you want to be very clever, bt in zone valves and thermostats for every room. Then buold a controller than can cope with all of that on a different basis from the rest of the CH.

Its possible to vastly overheat if you don't have some way of ensuring each room is at the right temp.

[The Natural Philosopher]

So? It also costs about 3 times as much to install. Who pays for fiuel? Who pays for installation?

Go figure (assuming your un snotty Uni taught you (a) the meaning of the word and (b() how to do it).

[The Natural Philosopher]

On the contrary, people have been insulting the Irish and their houses for decades.

You must try harder to get your facts right. gamma minus.

(usual ill informed drivel deleted)

[Peter Parry]

Repeating something ad nauseum does not make it true. Between 1968 and 1975 Gas was the most expensive fuel followed by coal then off peak electricity and the cheapest was oil. During this period gas was twice the price of oil and 50% more than electricity in cost. The price of electricity rose between 1975 and 1976 and gas and electricity became more or less equal in price and jointly the most expensive fuels until 1980/81 when oil prices rose and oil became the most expensive until 1985. In 1986 oil prices fell and oil became the cheapest fuel again.

Gas prices fell and gas became the cheapest fuel between 1979 and

1982 when electricity became cheaper. Electricity remained cheaper than gas between 1982 and 1990. Oil remained the cheapest heating fuel from 1986 to 2000, Gas was the second cheapest between 1992 and 1999 and, for the first time since 1982, became the cheapest in 2000.

(Source- ONS Fuel Price Indices for the Domestic Sector 1970 - 2000)

[The Natural Philosopher]

Some of us are older than you for a start.

Prior to notrh sea oil and gas, oil was often cheaper than gas.

Electricity ought to be always more expebnsive, but strange pricing policies have made off peak occasionally cheaper than both.

(ad hminem drivel deleted)

[The Natural Philosopher]

(obviously written by some snotty uni bloke with shares in BP eh peter?)

Bring back nuclear power I say. Cheapests of the lot, no pollution and greenhouse gases, infinitely renewable supplies of plutionium etc etc :-)

[Suz]

It's pointless for us to insulate cos we have to keep the kitchen door open all the time to let the pigs run in and out.

Suzanne The Irish are a fair people, they never speak well of one another. Samuel Johnson

[IMM]

This is balls. Total balls. The reason gas took off was that it was cheap to run, far cheaper than electricity. Oil fluctuated with Arab wars and embargos.

< snip misinformation >

[IMM]

You have to focus. It was gas v lecky.

[geoff]

And guaranteed work for years to come for the clean-up companies.

[Andy Hall]

There is a PDF at

confirms Peter's points. See pp20. The figures are normalised at 1990 and go back to 1970 and forward to last year.

I think it must be right - it's too complicated for Alastair Campbell to have written it.

.andy

To email, substitute .nospam with .gl

[IMM]

Being there and doing it. In the late 1960s/early 70s people were installing gas CH systems in houses fitted with electric underfloor heating to keep bills down. Very nice in that if the gas CH was down the electric UFH could be turned on.