Heating on low and constant better?

djohn2002uk

TITEASCRAMP wrote: »

I have listen to both your points. Tonight I will turn the heating off when i go to bed. I will let you know how much difference it has made.

I think I am getting good value for money at the moment. £28 for 24/7 sounds fine ot me.
But i will try turning it off at night.

But don't just turn it off when you go to bed and on again when you get up. That will leave your house wasting heat for an hour or so after you're in bed and it will be cold when you get up. The most efficient is to set your timer to go off about half an hour before bedtime and to come on an hour before you normally get up, then the house will stay warm up till you go to bed and will be warm to get up in the morning and you will have saved on all that gas overnight.

TITEASCRAMP

djohn2002uk wrote: »

But don't just turn it off when you go to bed and on again when you get up. That will leave your house wasting heat for an hour or so after you're in bed and it will be cold when you get up. The most efficient is to set your timer to go off about half an hour before bedtime and to come on an hour before you normally get up, then the house will stay warm up till you go to bed and will be warm to get up in the morning and you will have saved on all that gas overnight.

Thanks thats what i have done i have set it this morning. Its goinf off at 10pm and coming on at 5.30am Cheers

MancBrel

Cardew wrote: »

Re your post above; lets get into pantomime mode shall we.;)

"Oh no it doesn't!" say I

"Oh yes it does" says you.

I have every manual, website, engineer, Government publication and the law of thermodynamics on my side.

You have titeascramp on your side.

Ok I concede you are correct;)

I wish I had listened to that advice earlier as when I come to the USA I turn my heating and HW off in my UK house. I obviously should have left the heating to "constantly top up in very short bursts". Silly me I thought I was saving money by switching it off.;)

For those still on planet earth.

I am about to enter my second winter of this method (on constant, but low) and for me it works perfectly. I have a thermostat control (with no Off button) that allows me to set 2 seperate temperatures whenever I like, over 24 hours. So I set it a bit lower at night (as it gets colder) than during the day. The upshot is that I get a constant comfortable temperature for pretty much the same cost as having it come on twice a day when I'm in. Actually if I am honest, it's a little bit cheaper.

But the best advice I can give is for you to try it for a week, and record your usage (it takes a few days to get to grips with the best temperature). Then you can decide for yourself.

After my new boiler was fitted, both Engineers advised me to try this method, and although I doubted them, they were absolutely right.

My wife has turned the thermostat down to a level that has practically turned the heating off before now, when we go out. The upshot being that we returned to a cold house and the boiler had to go into overdrive to heat up the house for about 90 minutes until we were comfy. Using more gas in the process than we would normally use all day.

Go on, shoot me down!!!!

espresso

djohn2002uk wrote: »

This gets more and more confusing.
1. You have messed up the forum display width on my PC.

Because yours is a different resolution monitor compared to the normal 1280 x 1024 screen resolution.

2. Your copy of post 63 is a mixture of Verdana and Times New Roman as Cardews was, but is all 1point.

Which does prove that we see different to what Cardew sees but what you are seeing in not 1 point, it is a screen dump of my screen, which looks smaller when displayed on your screen.

f107btx

MancBrel wrote: »

For those still on planet earth.

I am about to enter my second winter of this method (on constant, but low) and for me it works perfectly. I have a thermostat control (with no Off button) that allows me to set 2 seperate temperatures whenever I like, over 24 hours. So I set it a bit lower at night (as it gets colder) than during the day. The upshot is that I get a constant comfortable temperature for pretty much the same cost as having it come on twice a day when I'm in. Actually if I am honest, it's a little bit cheaper.

But the best advice I can give is for you to try it for a week, and record your usage (it takes a few days to get to grips with the best temperature). Then you can decide for yourself.

After my new boiler was fitted, both Engineers advised me to try this method, and although I doubted them, they were absolutely right.

My wife has turned the thermostat down to a level that has practically turned the heating off before now, when we go out. The upshot being that we returned to a cold house and the boiler had to go into overdrive to heat up the house for about 90 minutes until we were comfy. Using more gas in the process than we would normally use all day.

Go on, shoot me down!!!![/quo

f107btx

f107btx wrote: »

MancBrel wrote: »

For those still on planet earth.

I am about to enter my second winter of this method (on constant, but low) and for me it works perfectly. I have a thermostat control (with no Off button) that allows me to set 2 seperate temperatures whenever I like, over 24 hours. So I set it a bit lower at night (as it gets colder) than during the day. The upshot is that I get a constant comfortable temperature for pretty much the same cost as having it come on twice a day when I'm in. Actually if I am honest, it's a little bit cheaper.

But the best advice I can give is for you to try it for a week, and record your usage (it takes a few days to get to grips with the best temperature). Then you can decide for yourself.

After my new boiler was fitted, both Engineers advised me to try this method, and although I doubted them, they were absolutely right.

My wife has turned the thermostat down to a level that has practically turned the heating off before now, when we go out. The upshot being that we returned to a cold house and the boiler had to go into overdrive to heat up the house for about 90 minutes until we were comfy. Using more gas in the process than we would normally use all day.

Go on, shoot me down!!!![/quo

I totally agree with this post.

mech_2

Cardew wrote: »

TITEASCRAMP
How you, or anyone else, choose to run your heating is obviously your business and nobody is making any criticism of you or anyone else.

However this is a money saving site and from time to time this urban myth that it is cheaper,or as cheap, to leave CH(AT THE SAME TEMPERATURE), and Hot Water on 24/7(with a HW Tank). From what I see MancBrel still sticks to that line!

It might be an urban myth in general, but not in every case. Your refusal to acknowledge the observations is based purely on faith. If the theory doesn't fit the facts, the theory needs modification. That's scientific method. The whole reference to the "laws of thermodynamics" is this context is oversimplistic in the extreme. I'll expand on that later.

The point several of us were making, to others reading this forum for advice on how to save money, is that it most definately is not cheaper.

It's not definately (sic) anything. Of the web pages you referred to (the ones that actually addressed the issue, that is. Some of them didn't as far as I could tell) two of them used words like "probably" and "generally", so they don't even rule out exceptions.

Nothing until now from the 'leave it on constantly' brigade's posts in this thread indicated you were demanding a higher temperature when on timed heating; despite the question being raised. So it was quite reasonable for anyone to assume that your 'experiments' were conducted using the same set temperature.

Actually that's exactly what I thought was being discussed from the start. Go back and read the thread properly. But I would still maintain that even at the same temperature, it doesn't necessarily save money to switch the heating on and off for a few hours at a time. Go and look up the term "thermal mass". Also consider what other parts of a gas central heating system the 2nd law of thermodynamics applies to, apart from just the air in the house and the air outside the house. Also consider what factors might increase loss of heat in the boiler's exhaust gases. In particular what might cause a condensing boiler to drop out of condensing mode (and thus wasting all that latent heat).

Also comments such as "it depends on the type of condensing heater" and "Heating up a house that has been allowed to chill uses the same amount of gas than constantly topping up with very short spurts of heating." are both irrelevant and totally incorrect.

Why? Do you know how a night storage heater works?

Obviously if you turn down the temperature and have it low 24/7 it can be as cheap. It depends of course how low you set it for the 24/7(regardless of TRV's or room thermostat) Taking it to the extreme if you set the temperature to 10C you will save a stack of money!!

This is true. I would find 23 degrees C uncomfortably warm, even in a T-shirt. My room-stat is set at 18 degrees and I use half the gas I was using when I had a German girl staying here who kept turning it up to 24.

But this merely serves to illustrate the main point. The British Gas page you linked to said you "could" save up to £16 a year by switching your heating off for most of the day. Out of an (average?) £500 gas bill that's nothing! And "could" implies possibly less! You could probably save more by optimising the system for running constantly.

And for someone who's at home all day, saving £16 a year by letting the house cool down would be total madness! Who cares if it costs an extra 4p a day? you'd get better value for money if you were comfortably warm.

Cardew

mech wrote: »

It might be an urban myth in general, but not in every case. Your refusal to acknowledge the observations is based purely on faith. If the theory doesn't fit the facts, the theory needs modification. That's scientific method. The whole reference to the "laws of thermodynamics" is this context is oversimplistic in the extreme. I'll expand on that later.



It's not definately (sic) anything. Of the web pages you referred to (the ones that actually addressed the issue, that is. Some of them didn't as far as I could tell) two of them used words like "probably" and "generally", so they don't even rule out exceptions.



Actually that's exactly what I thought was being discussed from the start. Go back and read the thread properly. But I would still maintain that even at the same temperature, it doesn't necessarily save money to switch the heating on and off for a few hours at a time. Go and look up the term "thermal mass". Also consider what other parts of a gas central heating system the 2nd law of thermodynamics applies to, apart from just the air in the house and the air outside the house. Also consider what factors might increase loss of heat in the boiler's exhaust gases. In particular what might cause a condensing boiler to drop out of condensing mode (and thus wasting all that latent heat).



Why? Do you know how a night storage heater works?



This is true. I would find 23 degrees C uncomfortably warm, even in a T-shirt. My room-stat is set at 18 degrees and I use half the gas I was using when I had a German girl staying here who kept turning it up to 24.

But this merely serves to illustrate the main point. The British Gas page you linked to said you "could" save up to £16 a year by switching your heating off for most of the day. Out of an (average?) £500 gas bill that's nothing! And "could" implies possibly less! You could probably save more by optimising the system for running constantly.

And for someone who's at home all day, saving £16 a year by letting the house cool down would be total madness! Who cares if it costs an extra 4p a day? you'd get better value for money if you were comfortably warm.

I am afraid your post is full of contradictions as albertross has gently pointed out.

I will concede I spelt ‘definite’ wrong in an earlier post and I do believe the law of thermodynamics is always correct.

Let us take what you term as the "main point" of your post and throw a little more light on the example you wished to "illustrate":

The British Gas page you linked to said you "could" save up to £16 a year by switching your heating off for most of the day. Out of an (average?) £500 gas bill that's nothing! And "could" implies possibly less! You could probably save more by optimising the system for running constantly.

And for someone who's at home all day, saving £16 a year by letting the house cool down would be total madness! Who cares if it costs an extra 4p a day? you'd get better value for money if you were comfortably warm.

Firstly I didn’t post any links except from the Energy Saving Trust. However the statement in the British Gas link states:

Set your heating to turn off before you leave the house and go off 30 minutes before you go to bed and you could save £16 a year

It would appear(unbelievably) that your interpretation of that BG statement is that the difference between leaving heating on constantly(24/7) and switching it off is £16 a year.

Does it not occur to you that the words “before” and “30 Minutes before” have some relevance?

i.e. BG mean ‘turn your heating off before you go out, instead of AS you go out’ and ‘turn your heating off 30 minutes before you go to bed instead of AS you go to bed.’?

If you think you have read it correctly, is the saving £16 regardless of you going out for an hour, 12 hours, a week, a month, or a year?

Given your ability to read and understand what is written, it is slightly ironic that you suggest I go back and read the thread again.

mech_2

albertross wrote: »

If the theory needed modification, then it would have been modified by now, by a scientist following rigorous experiments, there is a scarcity of links to these experiments in this thread, or any 24/7 advice from a reputable body.

Can you link to a rigorously performed experiment by a scientist that compares gas usage when turning the gas off during the night/when at work versus leaving it on all the time? I can't. But I have performed the experiment myself with a conventional boiler and no double glazing several years ago. My gas usage was roughly the same in both cases with the thermostat set at the same room temperature (20 degrees C back then). This was for a whole year in each case, so seasonal variations should have been evened out (2003 versus 2004).

With a condensing boiler and double glazing I don't find it hard to believe there could be a saving when run continuously. With the boiler running at full load (and probably cycling) to pump all that heat into a cooler house, it probably never enters condensing mode at all, thus running 12% to 15% less efficiently (as the radiators can't move the heat into the air fast enough to keep the return temperature low).

Thermodynamics may be complex, but your German experiment proves the point quite conclusively does it not? The 24/7 theory goes that if you left it on at 24 degrees, then it would cost a bit extra to heat it up to 24 on the first day, and then magically it would cost no more to maintain that higher temperature, which is not what happened, your bills doubled, because you don't live in a vacuum.

It proves what? It just proves a house loses more heat when it's hotter. That applies whether the house is heated 24/7 or for just an hour in the morning and a few hours in the evening. I didn't dispute this.

The turn the stat down low brigade before you go to bed just don't seem to get it that potentially has a very similar effect to turning it off completely, by the timer, it depends what low means, and what the outside temp is.

Well maybe in the warmer months of the year when one uses little gas anyway. But most of the gas used to heat a home is used in the winter when turning the thermostat down 4 degrees from 20 to 16 is still going to keep the boiler firing up occasionally when it's below 5 degrees outside.

The debate is really whether it's better to let all that stored heat go and then replace it later, or to just keep topping it up so you never have to drive the heating system hard. I now have a modulating condensing boiler and I know it's more efficient than the generalised SEDBUK rating when topping up the temperature continuously at part load, and less efficient than rated when at full load and/or not in condensing mode. Surely it therefore makes sense to optimise its usage to keep it in condensing mode? Especially when I know it takes more than 24 hours for all the heat to leave the fabric of my house even when it's near freezing outside (I still don't have double glazing either).

mech_2

Cardew wrote: »

I am afraid your post is full of contradictions as albertross has gently pointed out.

He did?

Firstly I didn’t post any links except from the Energy Saving Trust.

Oops. My apologies. Indeed, they were posted by albertross. I lost track of which person I was responding to.

It would appear(unbelievably) that your interpretation of that BG statement is that the difference between leaving heating on constantly(24/7) and switching it off is £16 a year.

Does it not occur to you that the words “before” and “30 Minutes before” have some relevance?

i.e. BG mean ‘turn your heating off before you go out, instead of AS you go out’ and ‘turn your heating off 30 minutes before you go to bed instead of AS you go to bed.’?

Well you have a point there. I have to concede that you're probably right. But I contend that the statement is ambiguous. It could mean either in the context of this thread. Especially when submitted as evidence. It seems to me that albertross made the same interpretation as I did, or the link would have to have been irrelevant.

If you think you have read it correctly, is the saving £16 regardless of you going out for an hour, 12 hours, a week, a month, or a year?

If it was meant to be that vague they couldn't have put a yearly figure on it could they? The assumption is that they mean every day.

Given your ability to read and understand what is written, it is slightly ironic that you suggest I go back and read the thread again.

Slightly, but what I misunderstood was ambiguous. Your misunderstanding was simply from not reading what was written.