What's the cheapest way to run my heating?

Leif

Jaynne wrote: »

One of the problems is there is a misunderstanding of themodynamics here. Leif in post #27 I'm afraid what you said is completely wrong.

In a house it will take X W of energy to keep the house 1 degree above the outside temperature however to keep the temperature at 10 degrees more than the outside you don't require 10X of heating but much more. It isn't a straight line but an increasing curve.

If you think about it in terms of a an extremely long tandem bicycle with 10 riders they can comfortably each move the bike at 15 mph do they go at 150 mph when all of them are on? No because the friction of the road increases hugely the faster you go creating more drag so they go much slower.

The energy to keep a house at a constant temperature when not in use is more than quickly heating it up from cold depending on essentially two factors. How long the house is empty (ie heating not required) and how insulated it is. The better insulated it is and the more time you will be in requiring heating the more sensible it is to leave the heating on all the time.

A typical person who isn't in most of the day and only has the heating on for 4 or 5 hours a day will waste huge amounts keeping a background temperature for the other 19 hours.

What did I say that was completely wrong? As far as I can see, your above post just repeats what I said. :question:

"In a house it will take X W of energy to keep the house 1 degree above the outside temperature however to keep the temperature at 10 degrees more than the outside you don't require 10X of heating but much more. It isn't a straight line but an increasing curve."

Yes, because there is a larger thermal gradient, as I explained. That is the reason why turning off heating can save money.

Jaynne

Leif wrote: »

What did I say that was completely wrong? As far as I can see, your above post just repeats what I said. :question:

serves me right for not reading the whole thing, read the first 4 lines and stopped

You are completely correct.

Leif

Jaynne wrote: »

serves me right for not reading the whole thing, read the first 4 lines and stopped

You are completely correct.

Phew! Thank you. I thought that might have been the case. It can be a bit tedious reading through all posts in a thread.

Avoriaz

Is it cheaper to leave the heating on low or to turn it off when not required?

The answer is very simple if you look at the first law of thermodynamics, which can be summed up as “the exchange of heat between two bodies is proportional to the temperature difference between them.”

In other words a warm house loses more heat than a cold one.

Keep the heating on low and the house will lose more heat than if it is allowed to cool down.

The more heat the house loses the more it costs to replace that heat.

Very simple and very true.


OP, do what most sensible people do. Insulate your house as best you can. Eliminate draughts but make sure you have some fresh air coming in.

Keep the maximum temperature at the lowest level that you find comfortable. Putting extra clothes on rather than turning the heating up is cheaper but not necessarily the most comfortable.

Use the TRVs effectively so that rooms that don’t need it are not being overheated.

Turn the heating off about 30 to 45 minutes before you leave the house. You probably won’t notice the drop in temperature.

Set the timer to turn the heating back on again a while before you plan to return home. Experience will tell you how long before you get home that should be. It will be longer in colder weather. There are some smart timers that can vary that time according to external temperatures but that is probably overkill.


Edit: Do you have a frost stat setting that will turn the heating on if the temperature gets very low, usually below about 5 degrees. That isn't really relevant for a day out at work but it is useful for weekends away or holidays. It keeps the house from getting so cold that water pipes might freeze and split.

Leif

keithgillyon wrote: »

some of my customers have degrees & letters after their names but when it comes to anything practical they haven't got a clue, as someone else pointed out in another thread passing exams in a classroom without practical experience means diddly squat,

Firstly, I hope you don't mind me selectively quoting, I don't think that is wrong here. I agree, some people with degrees are damned useless. They can talk a good talk, but they are not very practical. But I hope you do not think that is a general trait. Please see my comments later which relate to this. I could also say "Oh those trades, bit thick, wouldn't trust them to understand anything other than the Sun, and even then they find the words challenging". But that would be a) offensive and b) completely untrue. Actually the good ones are intelligent people. The ones who are thick - a minority I assume - are not good trades. My neighbour is a retired upholsterer, and I am always asking him questions as he is so useful. He know so much about DIY given that he does so much himself, and does it well.

keithgillyon wrote: »

I haven't got a university degree in anything but that doesn't mean I'm thick & it also doesn't mean that I am any less intelligent than you I just choose a different path in life, do I get angry when I'm wrong no I don't am I willing to learn yes I am, but yes I do get annoyed when people talk down to me as if they are better than me,

I don't think anyone talked down to you, and I certainly hope I did not.

keithgillyon wrote: »

I don't pretend to know everything but some things you can only learn in a real life situation & with experience, qualifications mean absolutly nothing if you can't put it into practice, why do you think there are so many really highly qualified university students that can't get jobs ? because employers are looking for someone to do the job not sit there all day anilising the best way to do it, so you can spout all you want about how intelligent you are & how many letters you have after your name it makes no difference to me at all, I go by practical experience not a piece of useless paper (unless of course I want to set fire to it to keep warm), ooo I wonder how much of that will get quoted

There is useful knowledge, and academic knowledge, which can be useful, at times. Plumbers, bathroom fitters etc can earn a decent living (or at least they could before half of Eastern Europe moved here) because they have useful knowledge. You are correct that having, for example, a degree in physics means nothing when it comes to doing plumbing. I would employ a plumber, not a physicist, to do plumbing. But don't underestimate for example physicists, and more importantly, engineers. Most people I work with are engineers. And most do their own bathrooms, kitchens, and so on. And they do a good job. That is because they have been trained to think in a logical manner, and as engineers, they have the ability to think things through, to conceptualise, just as a good trade does. My problem is that it takes so long to think through a task, but once I've solved it, the next time I do it, I can do it quick.

By the way, I do think you are probably right that in some cases it it really is best to leave the heating on low during the day, for the reasons you say i.e. you want the house comfortable when you get home. This would depend on the insulation and heating system I guess. I don't doubt you have far more experience of what works in practice to keep people comfortable. But don't discount academic knowledge. It was academic knowledge that explained why some bridges fell down when troops walked across in step. :eek: Now troops are told not to march in step across bridges.

Avoriaz

Leif wrote: »

..By the way, I do think you are probably right that in some cases it it really is best to leave the heating on low during the day, for the reasons you say i.e. you want the house comfortable when you get home. ...

The OP wanted the cheapest method of running his heating.

What's the cheapest way to run my heating?

Looking ahead to the autumn, I wonder if someone could please give me advice on how best to manage my new central heating to keep my bills as low as possible?

......I really can't afford to pay a penny more for my heating than I have to, so I need to plan ahead.

Leaving the heating on low isn't the cheapest method. He will be spending money heating the air outside his house more than necessary.

No amount of aggressive rudeness changes that fact.

cyclonebri1

I can probably complicate opinion even further here, so consider this situation and feel free to comment.

We have a 4 bedroomed home, it's a bungalow with a 2nd story addition, 2 double beds and a bath plus large walk ins. Kids have now departed and we have effectively shut down the upper floor. The rads are set to frost protection, the rooms are ventilated whenever possible and there is an open staircase to the upper floor, so a reasonable amount of heat rises to the landing. I did consider curtaining off this area at the top of the stairs but had safety concerns.
Sensing this situation would happen one day when I did this conversion I was able to drop the 8ft 6" ceilings below to 7ft 9" and add 9" of rockwool.

Yes, we do run the heating up there some times if we have people staying or just to exercise the system and yes, we should move and down size, but the hell with that, too much of me life invested here, they can bury me up the garden. :A:A:A

southcoastrgi

Thank you Leif, that was a very intelligent, well thought out & sensible post, I do not for one min think that people with degrees, trained engineers etc are thick or stupid, they are prob far more intelligent than myself & could certainly teach me alot about things I don't know, my only gripe on this thread is that the OP's question was about a real life situation & my 30 yrs of experience as a heating engineer/technician whatever the trendy name is now have led me to believe the answer I gave was the correct one, I do not have the knowledge to work out the thermodynamics of this question nor do I need to, if I was designing a shopping centre or a huge factory unit then yes these things would come into play & I would be the first to admit that I would be out of my depth, as you quite rightly point out it is horses for courses, I only go by my experiences in things working & some things not.

southcoastrgi

cyclonebri1 wrote: »

they can bury me up the garden. :A:A:A

Or burn you on the living room fire to keep the heating bills down (providing of course your house is well insulated & all the heat doesn't go up the chimney)

cyclonebri1

keithgillyon wrote: »

Or burn you on the living room fire to keep the heating bills down (providing of course your house is well insulated & all the heat doesn't go up the chimney)

With my alcohol content, they wouldn't dare, :D