How ecconomical is leaving the heating on all day?

mech_2

ixwood wrote: »

You do know that freezing point is 0? Why would you have it on 15 when when you're not there?

I think the question is: if you knew from experience it wasn't costing a lot of money, why wouldn't you?

My heating is not on now and it's 9 degrees in the hall and kitchen. It'd take a VERY cold spell to get it down to 0 inside.

I think that's the point really. On a day-to-day basis, houses don't tend to lose enough heat for switching the heating on and off to make much difference (though not necessarily all houses) and on the cold days when it might make a meaningful difference it's less comfortable when you get back in and house is warming up.

Obviously if one goes away for several days or longer it makes sense to turn it right down close to zero.

Heating an empty house to stop damp and mould is madness IMHO. You get damp and mould when the moisture content in the air is too high. If you have dry air, the temperature is irrelevant.

But warm air isn't likely to be dry. At normal humidity levels for a living space it will contain moisture. Cool air can't hold as much moisture, so when the warm air cools the relative humidity figure will go up, even if the total moisture isn't any greater. Then one runs the risk of condensation. You can mitigate this with extra ventilation, sure, but this risks wasting more energy than a lower level of ventilation with a warmer air temperature.

hansi

Wickedkitten wrote: »

You would be better off improving your ventilation really. Even nowwe sleep with the window cracked and first thing in the morning I throw back the duvet cover and leave the windows open (mind I am in the house at the time).

You have a cracked window? I would get that repaired ASAP

ixwood

Blackpool_Saver wrote: »

I should hope so, I was reasonably well educated as Princess Anne once said !!

I leave it on at 15 so it doesn't drop, I am in a detached end house with lots of exposed walls.
It's not the boiler it's the pipes along the outside walls that worry me re the freezing possibility.
I don't have a combi, like you, it's a storage tank.
I have a medical condition requiring extra warmth.
Thanks for your reply.

15 is 15 above freezing. I don't see what relevance your pipes have. If the room was 5 or 10 degrees, your pipes aren't going to freeze regardless of location.

It'd be more sensible/greener/cheaper to set it at 4 or 5 when the house isn't occupied IMHO.

ixwood

mech wrote: »

I think the question is: if you knew from experience it wasn't costing a lot of money, why wouldn't you?

True. But is that really the case? Keeping my house at 15 permanently would certainly cost a fair amount extra.


I think that's the point really. On a day-to-day basis, houses don't tend to lose enough heat for switching the heating on and off to make much difference (though not necessarily all houses) and on the cold days when it might make a meaningful difference it's less comfortable when you get back in and house is warming up.

Would you leave a kettle permanently on when you're not there, so you have hot water when you get in too?

I do have an old, draughty house, so that's maybe why I think heating an empty space is madness/expensive.

Obviously if one goes away for several days or longer it makes sense to turn it right down close to zero.


But warm air isn't likely to be dry. At normal humidity levels for a living space it will contain moisture. Cool air can't hold as much moisture, so when the warm air cools the relative humidity figure will go up, even if the total moisture isn't any greater. Then one runs the risk of condensation. You can mitigate this with extra ventilation, sure, but this risks wasting more energy than a lower level of ventilation with a warmer air temperature.

I understand relative humidity and temperature, though I don't agree with your conclusion.

Heating takes much more energy than ventilation and dehumidifying. It'd be much more efficient to remove the excess moisture in the air that it would be to maintain higher temperatures permanently.

ixwood

Katie-Kat-Kins wrote: »

Because with the thermostat down to 17C it won't actually be on much, just if the temperature drops very low, and it would be a bit unpleasent if it did drop much lower than this even if you are in bed.

If your heating is on but with the thermostat down low it will be off unless your house temperature drops below a certain level.

The temperature on the thermostat doesn't relate to the temperature that the heating is working at, it relates to the temperature which the heating is attempting to maintain in the room. It will cycle on and off to reach an maintain this.

Realistically turning down to 17C overnight might mean that you get one half hour top up in the night but don't wake up cold or get nasty drafts through any gaps in the covers. And then when you turn it up in the morning there will be less work for your heating to do as the temperature of the house will not have fallen so low. So maybe instead of working solidly for an hour to get your property from 15C to 20C it will only have to do half an hour to get from 17C to 20C.

The figures are just examples, just to illustrate how thermostats work and how leaving your heating on with the stat turned down isn't as bonkers as some people on here seem to think. There seem to be a lot on this site that don't understand the principle of a thermostat switch.

I'm not sure who you think doesn't understand how thermostats work.

To say it'll just come on for 30 mins a night is wrong IMHO. When the temperatures are minus overnight, like they have been for the last week, you'll be wasting a lot of energy/money.

It's normal to set it to come on for 30 mins or an hour before you get up to avoid getting up to a cold house.

Rebekah24

I keep the heating off, only have the living room on when I am there. Heating bedroom is unnecessary unless its going to be subzero

All about saving money! Layer up..and air the house out if your worried about ventilating/damp

roddydogs

LisaLou1982 wrote: »

Why would you have your heating on when you are in bed??!!

Depending upon the construction and size of your property, the heating up times will vary. If you have a large property with solid walls and a high pitched roof with no insulation obviously 30mins might not be long enough. However, an average sized bungalow with loft insulation and Cavity Wall insulation should be warm enough within 30mins with a modern heating system

My Bungalow is totally insulated including Cavity wall insulation if the heating goes off for the 8 hrs im in bed, the temperature will drop to about 55F, and will take much longer to get back to 70F, the thermostat is in the living room, not the bedroom.
If im away for more than 24 Hrs, it will take at least 10 Hrs in this weather to heat up to 70c, so thats why i leve it ticking over.