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

kevinshome

You want to check your insurance policy, as you may find that the Insurance Company have stipulated that your heating should be left on around 15c to reduce the risk of burst pipes. So if your heating wasn't on, as they suggested and a burst pipe or frost damage does occur then is your insurance policy invalidated? I for one control my heating using the thermostat and leave it on around 13/14c and turn it up as and when needed. I also make sure I review my energy provider each year thoroughly for the best deal, so at the moment my bills are reasonably low. How long that lasts is anybodies guess because the authorities have given these vulchers extra claws. Why isn’t there a public debate on energy equality/rise increases with our so-called European counter parts?

macman

docnarrative wrote: »

Someone has told me that it's significantly cheaper to run a freestanding convector heater (with thermostat) than a freestanding oil-filled panel radiator (also with thermostat) to keep a constant base temperature going. Is that correct?

Complete nonsense-since all electric heaters of whatever kind have the same efficiency (100%), they all cost excactly the same to run, for the same rated output. So just buy the cheapest.
The only difference between the two is the method of delivery. An oil-filled rad is slower to produce full output, but retains some residual heat after switch-off. But the cost per kWh is the same.

macman

kcletheroe wrote: »

Ok, this is my first post on the forum so please be nice!

I was told to keep my thermostat on at 15°c so that there is not a a lot of energy required to come up to temperature.

I would like to know if 2 hours at 20°c is cheaper and more efficient than 20 minutes at 30°c?

Also, how do I put reflective material behind the radiators? There is a very small space. Do they need taking off? I live in a housing association flat.

Thank you,

:question::question::question::undecided:undecided

Ignoring the fact that you are still inputting energy 24/7 to keep it at 15C (assuming that the ambient temp is below 15C of course)-which is too cold for comfort anyway!

Cardew

kevinshome wrote: »

you may find that the Insurance Company have stipulated that your heating should be left on around 15c to reduce the risk of burst pipes.

Why 15C? that is far too high for preventing frost damage.

Most CH systems have a 'frost stat' specifically designed to prevent frost damage - mine is set to 3C and in a little used annex to 2C

http://www.qvsdirect.com/Salus-Frost-Thermostat-pr-20766.html

maxmiler

Cardew wrote: »

Why 15C? that is far too high for preventing frost damage.

Most CH systems have a 'frost stat' specifically designed to prevent frost damage - mine is set to 3C and in a little used annex to 2C

http://www.qvsdirect.com/Salus-Frost-Thermostat-pr-20766.html

My boiler, thermostat and TRVs are all designed to turn on at 5 degrees C when on frost setting.
I think that a higher temperature might be required if you have water up in the roof space.

Cardew

maxmiler wrote: »

My boiler, thermostat and TRVs are all designed to turn on at 5 degrees C when on frost setting.
I think that a higher temperature might be required if you have water up in the roof space.

Agreed.

I think that the manufacturers suggest that the Frost Stat should be in the coldest place in the house - which would indeed be the roof space if there was a water tank.

147718

Cardew wrote: »

1. Well firstly please make this thread a sticky as the 'Cheaper all day v timed' question comes up a dozen times each year.

The normal variation of that question is:

'Which is cheaper - on 24/7 at, say 15C or in timed bursts to 20C'

A question nobody can answer!

2. The EST have a fixation about standby consumption. The manufacturers got to grip with that problem many years ago and standby consumption for, say, TVs is tiny - fractions of a watt. You can leave a modern(up to 10 years old) TV on standby 24/7 for a year and the cost is pence. Even the worst of my TV's - an old 32" CRT has a standby consumption of 0.6 watts. so left on 24/7 it will cost 63p a year with electricity at 12p/kWh.

Obviously any saving by switching off at wall is welcome, but the emphasis on standby consumption leads many people to think it is the major cause of high electricity bills - and it aint! We get countless posts complaining about high electricity bills and nearly all are at pains to point out that they switch off TV at wall.

3. This is misleading IMO:



That might apply to the TRVs and thermostat in the same room. However the purpose of TRVs is also to control the warmth of other rooms. Most people would want their bedrooms set to a low temperature during the day which you can achieve with a TRV. e.g a reception room set to 21C and bedrooms to 16C

4. The recommendation to use an airer instead of a tumble dryer is questionable in modern houses that are almost hermetically sealed!! The problems of condensation and mould can be serious.

Could I ask a related question?
Each room of my house is fitted with thermostatic valves except the hall.
The hall has a room thermostat and the radiator in the hall is fully on Therefore the hall is often the warmest area in the house.
Would it be preferable to site the room thermostat in the living room which at present has 3 radiators and install a thermostatic radiator valve on the hall radiator?

macman

It's not good practice to have a room stat and TRV in the same zone, so ideally you'd 'swap' the TRV to the hall.

rgn007_2

The statement is misleading. I have already written why I know switching off is more expensive and not just about keeping warmer.

There are dynamics in between of course, but the Energy Trust I don't think is considering heat absorption of surrounding materials that sap out the warmth when you first turn your heating back on in a freezing room/house.

Even when an efficient boiler and modern thermostat is 'left on' 24/7 it isn't actually always 'on'. The system, in a well insulated home just keeps a lower base heat ticking over and boosts periodically to maintain that heat.

Being 'switched on' in my circumstances actually means available when the ambient temperature drops, and my graphs of energy consumption in therms over around 10 years trying it both ways clearly showed it was CHEAPER to never switch my boiler off, even in summer. Of course the boiler would just not fire up in summer but I just left it switched on in case as part of my long term experiment.

The above would not work if you had a drafty home or kept the ambient temperature above 17 degree C on a single temp system. My new system has 5 daily settings so at night it is set to 12 degree C and evenings 20 degrees C.

147718

macman wrote: »

It's not good practice to have a room stat and TRV in the same zone, so ideally you'd 'swap' the TRV to the hall.

I have 3 heated towel racks in the house which are always on when the boiler is firing Would it be acceptable to fit a TRV to the hall radiator and set the hall room thermostat to say 22 decrees so that each room including the hall was controlled by TRV's ?