is it better to leave the heating on low???

[charliecharlie]

my heating is on a timer... comes on for an hour in the morning and then back on at 7.0opm till bedtime... during this cold spell... when I am in in the evening it takes most of the evening for the house to warm up again...

Is it more eco/energy efficient to leave the heating on low all through the day even if you are out at work???

http://www.guyedwardes.com/images/nature/fullsize/Icicles,_Slovenia_fs.jpg

xx form chilly charlie

[giggirl]

Hey, where did you get that picture of my bedroom?

[Ann]

I think so, especially with high ceiling-ed Victorian houses. Can't quote figures or anything bit have left heating on low overnight in my house throughout the cold snap. If not during the night definitely consider it during the day.

[charliecharlie]

no no giggirl... that's my bedroom

and this is my bathroom

http://4.bp.blogspot.com/_Xq7E_pMxnCI/SXO0nD0iGcI/AAAAAAAADdQ/S80of1vKKuk/s800/2+Hoar-Frost-on-Grate-M.jpg

[Nero]

I suppose it depends on how well your home is insulated. Have you got draught-proofing, boiler-lagging, roof insulation and the like? My central heating is on from about 6 till 10 at night, but most of the rads are not on high and thermostat is never over 20C and it's warm (even when it is set at about 17C). I do wear a cardigan or jumper in the house, and socks. I'd bleed your rads regularly, too.

[Mick Mac]

Leave your wife at home charliecharlie - you will be sure to come home to a warm house in the evening. Not sure how she does it.

[charliecharlie]

have added double gazing front and back and have a well insulated loft... the house has always been cosy, but somehow this winter (since adding double glazing all the front window) is seems really had to keep the place warm... I'm wondering if it is more effective energy wise to keep the heating on low, rather that let the building temp drop so low during the day and night when heating's off...

[charliecharlie]

[quote=Leave your wife at home charliecharlie - you will be sure to come home to a warm house in the evening. Not sure how she does it.

]

have not got a wife... am a hetrosexual woman

[Sue]

Bedsocks and hat in bed is the answer, plus wear fleece, hat and scarf around the house.

Just don't let the postie see you.

Oooops I didn't say any of that :))

[reggie]

You are probably aware of one of Newtons lawa of thermodynamics which warns us that heat loss increases at a higher rate when

the temperature difference increases.

Which means a lower temperature house loses heat more slowly.

But keeping the house a bit warm all day and night might still use more energy than warming it up to a higher temp for some of the time. This would depend on the level of insulation.

Any questions?

[Mick Mac]

charliecharlie Wrote:

-------------------------------------------------------

> >

> have not got a wife... am a hetrosexual woman

i know that cc - was just a little joke about woman spending money...

[Sue]

reggie Wrote:

-------------------------------------------------------

> You are probably aware of one of Newtons lawa of

> thermodynamics which warns us that heat loss

> increases at a higher rate when

> the temperature difference increases.

> Which means a lower temperature house loses heat

> more slowly.

> But keeping the house a bit warm all day and night

> might still use more energy than warming it up to

> a higher temp for some of the time. This would

> depend on the level of insulation.

> Any questions?

xxxxxxx

Yes

[Mick Mac]

I guess he means relevant questions Sue....you can't just say "yes" surely.

[woofmarkthedog]

Yes ( warm )

Or No ( burning plenty gas )

Burn logs I say ( I can help )

W**F

*Rubs hands, to keep warm of course*

[Magpie]

It is an interesting question - my dad (clear authority here) reckons that keeping the heating on low for a longer time uses less gas as the heat is stored in the walls and radiates back through the house. This is opposed to the need to turn the thermo up high for a few hours when you get in at night just to stop your breath freezing. I certainly notice that at the weekends, when I have kept the heating on all day, I can keep the thermo lower than during the week. I guess it would be relatively easy to count usage via the meter to check this.

What it does do is make you think how bloody cold the victorians must have been in these drafty houses with only fireplaces to warm up rooms!

[intexasatthe moment]

If I were you I'd try setting it to come on about 4pm - great British compromise .

[KoolBananas]

Magpie Wrote:

-------------------------------------------------------

>

> What it does do is make you think how bloody cold

> the victorians must have been in these drafty

> houses with only fireplaces to warm up rooms!

You do realise they had real fires don't you and not those silly "display" things? ;-)

[brum]

You don't need to go back as far as the Victorian era. I remember growing up in the 60's without such luxuries as central heating and double glazing. One morning I woke to find it had been so cold in my bedroom, my poor hamster went into hibernation! (We did manage to wake him up by putting him next to the fire though).

[ClareC]

I went on a ski patrollers first aid course in a Victorian mansion based north of Manchester for a weekend about 5 years ago, my ex and I shared a room with two single beds, the condensation on the window had frozen and you could most definitely see your breath!!

It was so cold we ended up putting all the covers on one single bed and sharing that one despite the discomfort (we had been together 10 years + by that point so believe me sharing a single bed would never be a preference!!) plus wearing layers of clothes - was just about warm enough to sleep then.

I really feel the cold but he doesn't at all and has his green beret (ie RM commando course) which involves considerable discomfort yet he too found it really cold!

Makes me feel cold just thinking about it!!

[Pickle]

I'm at home all day with kids at the moment, and am very guilty of keeping the heating on non-stop. Do feel a bit guilty when Mr Pickle gets home from work and changes into shorts and t-shirt though (not sure he buys it when I claim the heating only just came on at 5pm) :-$

[Pandora]

It does depend on the type of house you have and how long it takes to warm up - a well insulated more modern house should heat up quicker than an older drafty solid wall property. It depends on how long it takes your house to heat up and cool down - the time it takes from turning the heating on to getting to a comfortable temperature, and turning it off and getting to an uncomfortable temperature. Even if it takes an hour to heat up, that's only an extra hour on your heating as opposed to leaving it on all day.

It should be more efficient to only have the heating coming on twice a day, but there is a way to check! Presuming you have gas central heating, read the meter at the start of the day and try leaving the heating on low, then read the meter 24 hours. Then do the same the next day, but leave the heating off. Obviously there might be different temperatures those days, and you might have varying gas use from water heating/cooking, but it should give you an idea.

Anyway, that was the general conclusion when I asked around the office (we do a lot of work on domestic energy efficiency). Getting rid of draughts will improve things (although sounds like your house is pretty good already) as will keeping the curtains shut after dark - so maybe leave them shut during the day if you're coming back after dark. And as much as we advocate saving energy, it is blimming cold at the moment so turn the heating on if you need to keep warm! And if you are struggling to pay energy bills there are various schemes out there which may be able to help, best people to contact are Energy Saving Trust.

[Huguenot]

The insulation etc. doesn't actually have an impact on the key question about whether to keep the heating on or not.

reggie's got the answer - it's about thermodynamics kind of. I'll put it in easily visualised terms although it's not strictly accurate:

Imagine a line drawn horizontally through the wall of your house from the inside to the outside. Then plot the temperature across it, from the inside to the outside. Let's say it's 20 degrees inside, and 0 degrees outside. The line would be level, and then a steep decline.

So that steep decline could be termed a 'temperature gradient'. Like a hill, things roll down it faster the steeper it is. Think of 'heat' like a ball rolling downhill, and you realise that the steeper it is, the faster it'll disappear!

Insulation then is like a 'rough' slope. It delays the 'heat' ball rolling.

But it doesn't get away from the fact that the ball will roll, and the steeper the hill, the faster it'll go (albeit slower than a ball on a smooth slope).

Hence your boiler will work less hard to increase the temperature from 10 to 15 degrees, than it will from 15 to 20 degrees, because it's losing less of its energy to the outside world at lower temperature gradients.

Let's say for example, that your boiler loses 30% of its energy externally at 10 degrees, and 50% at 20 degrees.

That means that 'average' loss in heating your house up from a low temperature at home time will be somewhere between 30%-50%. Whereas keeping it at 20 degrees it will always be 50% (a higher value).

It doesn't really matter what the 'real' figures are, or how good your insulation is. The temperature gradient calculation ensures it will always be more efficient to only heat the house when you need it.

[peckhamboy]

All of which is fine. But doesn't take into account that if your heating is on most of the time, your boiler will only actually be on for some of that time, whereas if you turn it off for a few hours it will then be on constantly for the next few hours to get back up to temperature. So that might mean that, overall, there's actually very little difference.

[charliecharlie]

some REALLY good advice hear... in the short term I am going to

1. have the timer come on a bit earlier in the morning and then come on at 4.00 instead of 6.30 (thanks intexasatthe moment)

then, if that's no better, I'll try

2. leaving it on low til SUMMER... bloody hell I'm cold...

http://friendsofthewestendparkatl.files.wordpress.com/2009/05/ice-cubes.jpg

3. then I am going to see if I can do any further insulating projects I can do for next year (when we will, no doubt, have a winter that is the hottest on record!!)

[Huguenot]

It does peckhamboy. That's life.

The difference between the two figures will depend on your insulation. If you've got very good insulation, there'll be little heatloss, little requirement from the boiler to reheat, and little difference. Poor insulation and the opposite happens.

But regardless of the size of the difference, it will always be there. That's physics for you.

Did you know a bullet drops to ground at the same rate regardless of whether it's been shot horizontally from a gun or dropped from your hand? Goes against intuitive thinking, but that's just the way it is. They even tried it on Mythbusters.