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

wantanswers

Very many years ago Malc when we were kids and gas wasn't invented we knew this bloke called Geordie Cockeye (don't ask).

His father kicked him out of the house for some reason, so anyway he decided to build a one bedroomed corrugated iron shed near to his father. We as kids used to block his chimney at night, the physics then were unrepeatable.....:)

Cardew

I really cannot believe some of the posts on this thread.

Can some proponent of 'on all day is cheaper' answer this question that was posed earlier:

So let us take the scenario where you left your house empty for 2 years -
presumably you wouldn't have it heated, and would accept that the ENORMOUS
amount of energy to bring it back up to temperature would be less than keeping
the house heated for 2 years.

How about 6 months?

1 month? 1week?
24 hours? 6 hours? 1 hour?

There must be a point at which YOU
consider the laws of Thermodynamics don't apply! What period of time would that
be?

Again, for your theory to hold true, you wouldn't let the
water in a kettle go cold because of the ENORMOUS amount of energy required to
bring it back to the boil. It would be cheaper to keep the water temperature
topped up all the time.

P.S.
Please don't raise the issue of what is
more comfortable, or preventing damp. This is about cost!

The EST - a Government sponsored organisation state unequivocally that the longer heating is off - the cheaper. So they must be wrong?(surely a sacking offence if they can't get it right!) As must every technical organisation be wrong - yet these hairbrained theories are still put forward to demonstrate that the laws of physics don't apply.

maxmiler

147718 wrote: »

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?

What I have done is to fit a wireless thermostat/timer at a cost of about £35. Every radiator (apart from the towel rails) has a TRV.
Usually the thermostat is in our living room for a constant 22.5 in the day and 17 overnight, but in early autumn and spring, when we have grandchildren staying overnight, I put the thermostat in the back bedroom at 18, wind this TRV open and set the rest of the TRV's very low or off. So then the bedroom is a constant temperature.
It's not hard to remember to wind the TRV fully open in the "new" room when moving the thermostat, and to adjust the TRV in the "old" room to 3 or so.
I did try the thermostat in the hall once. It was the worst place that it could ever be put - no control over the heating due to a variety of doors opening at various times.

grahamc2003

Cardew wrote: »

I really cannot believe some of the posts on this thread.

.

It's really quite funny! The myth seems to have more support than the physics. It's pretty sad when the energy saving measures of many here includes keeping the heating on 24/7! Don't bank on the UK's CO2 targets being met anytime soon!

bestyman

Did you know that a day on Venus last the same as 243 Earth days?

I bet if the Martians on Venus leave the heating on all day, it costs them next to nothing!

OK, technically Martians live on Mars not Venus, but you get the point.

wantanswers

grahamc2003 wrote: »

It's really quite funny! The myth seems to have more support than the physics. It's pretty sad when the energy saving measures of many here includes keeping the heating on 24/7! Don't bank on the UK's CO2 targets being met anytime soon!

Better call back Dr Emmett Brown if you want to convince people:)

Jems74

HI there

Just to throw a spanner in the works. I have a weather compensator fitted to my gas boiler. It has only been fitted recently. I am so unsure if it will work out cheaper for me to leave the boiler on 24/7 because I have been told with the compensator it controls the boiler switching it on and off when needed to top up the heat in the house it only uses small bursts of heat at a time. Is this true? Ive just had a bill in from Southern Elec/Gas and I owe £60 on both. I pay 60 on each, each month. Im in a 4 bedroom detached house which is not badly insulated. Could anyone advise whats best for me??:money:

Thanks in advance

HappyMJ

Jems74 wrote: »

HI there

Just to throw a spanner in the works. I have a weather compensator fitted to my gas boiler. It has only been fitted recently. I am so unsure if it will work out cheaper for me to leave the boiler on 24/7 because I have been told with the compensator it controls the boiler switching it on and off when needed to top up the heat in the house it only uses small bursts of heat at a time. Is this true? Ive just had a bill in from Southern Elec/Gas and I owe £60 on both. I pay 60 on each, each month. Im in a 4 bedroom detached house which is not badly insulated. Could anyone advise whats best for me??:money:

Thanks in advance

Assuming the weather compensator is set up correctly then you would set your boiler to reach a room temperature of ....let's say 18 degrees at 7:30am and it would come on at the correct time to bring the house temperature up to 18 at 7:30am. In summer that could be at 7:20am as there might only be a couple of degrees difference. The output of the boiler would also be set low and in winter that might be 6:30am or a little earlier and the output of the boiler would be high then once it has reached the set temperature the boiler output should automatically be set to low and stay on but with a low output maximizing the efficiency of the boiler and reducing any large temperature swings. If the temperature outside drops then the boiler output increases to prevent the room temperature dropping faster than the boiler can replenish it on low. It's supposed to automate it for you but you still need to set the temperatures and times on the programmer.

macman

Essentially what weather compensator does is adjust the start-up time in order to get the house to the required temp by a certain time, regardless of changing ambient temps.
It does not rewrite the laws of thermodynamics in order to magically make it more economic to keep your CH on 24/7!

malc_b

147718 wrote: »

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?

Are the lounge radiators sized right for the lounge losses? Are the radiators balanced? Balancing is setting the lockshield valve so the when running flat out and up to temperature the temperature drop across each radiator is ~20C. That way all radiators are getting their fair share of the heating water. TRVs do not mean you don't have to balance. If the system is not balanced then in the extreme just one radiator will get hot while the rest don't, until it's TRV turns off, then next one will get hot and so on.

Also, I'd advise against a thermostat in the lounge. I used to have but one Christmas will all the people and candle the lounge reached temperature with no heating. The rest of the house got very cold. IMO TRVs for the lounge and main thermostat in the hall is the right approach. The ideal would thermostats everywhere where anyone could call for heating but that's far too expensive.

I'd suggest turning down the lockshield valve on the hall a bit, say for a 25C drop across the radiator inlet to outlet. That will reduce the radiator output a bit as it sounds like the hall radiator might be oversized (f the system is balanced).