What's the cheapest way to run my heating?

robatwork

VoucherMan wrote: »

erm... *cannae

keystone

What's the cheapest way to run my heating?

I was going to flippantly say leave it switched off but the someone from t'other side of Offas Dyke beat me to it.

Cheers.

southcoastrgi

keystone wrote: »

I was going to flippantly say leave it switched off but the someone from t'other side of Offas Dyke beat me to it.

Cheers.

where have you been you have missed an interesting day

Leif

Avoriaz wrote: »

The OP wanted the cheapest method of running his heating.


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.

There are two key words there: cheapest, and heating. I assume he actually does want heating, in the sense that he feels comfortable in his home, rather than becoming an ice sculpture. Just a guess on my part.

keystone

So it seems. Would working be a reasonable excuse? If it ain't tough because thats what I have been doing.

Cheers

Avoriaz

London_Town wrote: »

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?

Would it be best to put my thermostat at 15 degrees to keep a background heat all the time, then just increase it if I need it in the evening? I had planned to not have it on at all when I'm not there and just fire it up when I get home but I've been told a constant background heat is cheaper to run. I really struggle to get my head round that one!
.

If you are still confused with all the conflicting advice, here is a simple example that may clarify the cheapest method of running your heating. Note “cheapest”, not “most comfortable” or “most convenient”.

Should you leave the heating on low or should you turn it off when not at home?

Anyone who understands the laws of thermodynamics will intuitively know the answer is the latter. Turn it off when you are not at home. The warmer you keep the house when you are not there the more heat it loses and the more money it costs to replace that lost heat.

How does that work? How do you prove that in simple terms?

Assume that you want 20 degrees when at home. Assume that the outside temperature is a steady 14 degrees. Assume that your thermostat has a 2 degree spread and, when set at 15 degrees will switch the heating on at 14 degrees and off again at 16 degrees. (Thermostats work a bit like that as switching at exactly the set temperature will cause rapid on and off cycling, which is undesirable.)

You leave the house at a certain time and the house temperature is 20 degrees. You have two choices:

Choice 1) You leave the heating on and set the thermostat for 15 degrees. After a while the house will fall to 14 degrees. The heating will come on and heat the house to 16 degrees. After a while the temperature will again fall to 14 degrees. The heating will come on again and heat the house to 16 degrees. This pattern will continue until you come home. When you come home the house will have been heated between 14 and 16 degrees a number of times. When you come home you find the house is somewhere between 14 and 16 degrees and you turn up the thermostat to heat the house to 20 degrees.

Choice 2) You turn the heating off. After a while the house falls to 14 degrees. It stays at 14 degrees until you come home. When you come home you turn it up and heat the house from 14 degrees to 20 degrees.

In Choice I the house has been heated from 14 degrees to 16 degrees a number of times and up to 20 degrees once.

In Choice 2 the house has been heated from 14 degrees to 16 degrees only once and up to 20 degrees once.

It is very clear that Choice 2 is preferable. You have avoided paying to heat the house from 14 to 16 degrees more than once.

Real life is more complicated that that, but the same principals apply. You may set the heating to come on before you get home, but that still avoids multiple heatings from 14 to 16. Outside temperatures vary, thermal gradients affect the rate of heat loss etc.

Real life calculations are more complex than my simplified example but, regardless of all that, you cannot beat the laws of thermodynamics when it comes to heating a house.

Turn it off when you don’t need it if you want to save money.

cyclonebri1

keystone wrote: »

So it seems. Would working be a reasonable excuse? If it ain't tough because thats what I have been doing.

Cheers

Well we all have bad days every now and then :o:o:rotfl:

Leif

Avoriaz wrote: »

If you are still confused with all the conflicting advice,

If you'd bothered to read the earlier posts you'd see that the problem was solved long ago. Time to move on, nothing to see here ...

Avoriaz

Leif wrote: »

If you'd bothered to read the earlier posts you'd see that the problem was solved long ago. Time to move on, nothing to see here ...

I read them.

There was a lot of conflicting advice and comments and the question had not been answered conclusively.

The OP wrote "I really struggle to get my head round that one!" He (or she) also wrote "Thanks to anyone that can provide constructive advice on these issue. "

My post was an attempt to help him with a simple but hopefully easily understandable example.

It was addressed to the OP with the opener "If you are still confused with all the conflicting advice".

I don't see why you have an issue with me attempting to assist the OP or anyone else why might have found my example helpful?

StuC75

Avoriaz wrote: »

Choice 2) You turn the heating off. After a while the house falls to 14 degrees. It stays at 14 degrees until you come home. When you come home you turn it up and heat the house from 14 degrees to 20 degrees.

In Choice I the house has been heated from 14 degrees to 16 degrees a number of times and up to 20 degrees once.

In Choice 2 the house has been heated from 14 degrees to 16 degrees only once and up to 20 degrees once.

It is very clear that Choice 2 is preferable. You have avoided paying to heat the house from 14 to 16 degrees more than once.

Real life is more complicated that that, but the same principals apply. You may set the heating to come on before you get home, but that still avoids multiple heatings from 14 to 16. Outside temperatures vary, thermal gradients affect the rate of heat loss etc.

Real life calculations are more complex than my simplified example but, regardless of all that, you cannot beat the laws of thermodynamics when it comes to heating a house.

Turn it off when you don’t need it if you want to save money.

What about if the drop in temp is more than 14-16.. What if unheated the house temperature say dropped to 9/10 (in winter when freezing outside).. How much more energy is taken to return from 9 to 14 then back up.. agree that if would only drop to 14 that its rather 'futile' to give the short reheat - but what if a higher range of temperature would be observed..

analogy being that the pan of water is 'simmering' (before returning to boil - shorter temperature range to cover) rather than being allowed to return to room temperature (larger range to then be covered).. Is a car more efficient driving at constant 50 mph, or stop starting between 0&70 (notice fuel efficiency always quoted on a constant load?)...

Interested to note your view of a Thermostat with 2degree tolerance is more effective than continuous off/on (shorter tolerance); as just gone through a year with a vokera wireless model thats been expensive on the gas compared to a previous house with a more featured programming - and strongly looking to replace that!..

Comfort (in efficacy terms) is probably more noticeable to Thermodynamics (efficiency)...