Energy myth-busting: Is it cheaper to have heating on all day?

Eco_Miser

2010 wrote: »

If it`s on it uses energy, if it`s off it don`t.

Depends what is meant by ON. From context, those championing always on actually mean controlled by thermostat only, in which case, with the thermostat turned low enough, the boiler never fires, so no energy is used.

[Deleted User]

Cardew wrote: »

You appear to have an Air to Air ASHP. The vast majority of ASHPs in UK fitted are Air to Water(Mitsubishi Ecodan etc) and can cost in excess of £10,000.

:think: I guess you could pay over £10k but I have an invoice here for the cost of a new 14kw EcoDan with installation for £4695ish inc vat... Not to bad really given the alternatives...

wantanswers

terry2 wrote: »

Well the original query the energy trust was replying too was probably wrong, what they should be comparing is the cost of having the heating on all the time at a constant comfortable lower temperature.

There have been lots of posts saying "heating on all the time" has to be more expensive. Well this would be true IF you kept the heating on with the same thermostat setting, but in fact you don't.

In my case (house built in the 60s with insulated walls and loft insulation and TRVs on radiators), I did lots of measurements of difference in temperatures (inside and out) compared with gas usage, for various conditions.

If I had the heating on twice a day then I needed to set the house thermostat at 20C to feel comfortable. If I left the thermostat at 20C and left the heating on all the time, then gas usage went up by 10% (BUT it took 48hrs for the house temperatures to stabilise before the usage was meaningful). However the house felt too hot at 20C 24hr. Dropping the temperature to 19C 24hr reduced the gas usage back to the original value; however the house still felt too hot. So I then tried 18C 24hr; in this state the gas usage was less than the original state (20C twice a day) and I still felt too hot. So I now run the house at 17C 24hr which still feels comfortable, and IS saving money.

So, being an experimental physicist and not a theoretician, I will continue to believe the measurements, ie it is NOT a myth: for many houses having the heating on all day with the thermostat turned down a few degrees WILL save you money, but note that after any change it will probably take the house some days to stabilise before you can check the usage.
Note that if you have an uninsulated house then this may well not be the case.

I'm doing the same Terry (experimenting)and saving, which suggests it is not a myth....

Also have you any info on night set back?


"You can save money on your heating and cooling bills by simply resetting your thermostat when you are asleep or away from home. You can do this automatically without sacrificing comfort by installing an automatic setback or programmable thermostat."

http://energy.gov/energysaver/articles/thermostats-and-control-systems

wantanswers

My mates just installed a 4 Kwhr max solar panel heating system @£6k (his cost) with all the latest gizmo's, controls, optimisers, HW tanks etc. Best investment he's made so he tells me.

macman

hamletp1g wrote: »

I cant fault the supposition that maintaining a given temperature 24/7 is the most costly way of running CH, but given that in my case that amounts to an increase of 5 pc on my heating bill I dont see any reason to change.

I dont think boiler efficiency is anything to do with lower return temp or turning it on and off as required, I thought it was the ratio of power in to power out. But no matter, every CH system will have an optimum way to be run, its just a matter of finding it.

I would have to dispute that it only adds 5% to your heating bill, 9as distinct from your total energy bill) unless you have a superbly well-insulated property. How many hours would you be running it if not on 24/7 in order to calculate that difference? Leaving it on all night (which is what most deluded people seem to do) must add more than 5%, as it's at night that the temp differential is at it's greatest. and therefore the rate of heat loss soars overnight if you keep adding more.

hubb

I decided to bite the bullet and have the heating come on and off all evening before we retired. When I got into bed the bed was just as freezing cold.

wantanswers

macman wrote: »

(which is what most deluded people seem to do)

Like that one.....:rotfl:

retiredin2011

Leaving it on all night (which is what most deluded people seem to do) must add more than 5%,

My heating bill, not including hot water and cooking and gas pilot light is £340, 11,000 kWh approx and for the sake of £17 I would rather pay the 5% or whatever for comfort than get up during the night to go to the toilet and freeze my !!!! off.

The government gives us £20 Christmas bonus so I spend it on comfort.

The £200 heating allowance is going on internal heating, booze.:rotfl:

zebb

An interesting debate (on the coldest day so far!) so I thought I would contribute some facts to it. Stats from the government website show that the average daily temperatures for the last 2 winters (Dec-Feb only - being the coldest time) were 3.3 and 5.3 degrees. Last winter was in fact the mildest for 5 years. Hence, any year on year comparisons are not probably not the best. I do agree that if we had it on all the time (we're in the twice a day camp) we'd probably have the temperature set lower - after all 18 degrees in summer = no heating so why all this 20+ degrees in winter lark! There's none so weird as folk! I'm sitting here in a tee shirt and TOH wants the heating on!

wantanswers

zebb wrote: »

An interesting debate (on the coldest day so far!) I'm sitting here in a tee shirt and TOH wants the heating on!

Likewise zebb,

Roomstat at 19 (comfortable) Outside below freezing and wind chill!

8.20am - 12 noon..... 23 kwhrs gas used 1 kwhr Electric.