How long do you guys have your heating on for?

[WoodYouLike]

so neither of you are willing to use timers

Not at the moment John, we had before and will again (when we move house, someday)
It's a very effective way to control the CH. Wearing a sweater too

 

[mrgtv]

so neither of you are willing to use timers

Kes, yes, there is science on it. Loss of heat is proportional to temperature difference x time. So keeping something hotter for longer means greater heat loss.

I use a timer which is why my house is warm when I get home without the heating being on all day.

You have summed up the situation very concisely and correctly in your last two sentences - well done!

 

[WoodYouLike]

I only heat my house up once, because I am out for most of the day. The one time fuel blast is less than all the little on off cycles throughout the day. Once we are both at max temp, we are then using the same fuel.
Clearly if you are only out for a short period of time, the situation changes.

You risk damp (possibly mould if you're really unlucky) when your house cools down so much every day.
A) not healthy and B) costs-wise not efficient too (in the long run of course)

 

[^woody^]

If your life involves getting up/getting home or being in and out at the same time every day, then timers may have a use.

If your life is a bit more unpredictable then not so much use.

I certainly would not like to live my life around what time the heating comes on or off, or be over-riding the timer everytime I am outside the pre-arrange time slots.

I know people who won't get up untill 1/2 hour after the heating comes on, and who use the heating going off at night as a prompt for when they need to go to bed

 

[gcol]

Mine's on permanent in the cooler months - won't do to have the hound being cold while we're out.
Anyone know if you can get thermostatic valves with built in timers so I can shut the rads off in rooms not occupied at certain hours? Boiler is a combi by the way.

 

[peterpumpkin]

I had thought about this for some time, the only time we had the heating on full time was over christmas.(Usage 52 cu mtres) I experimented in november, when it wasn't all that wintery,Leaving the heating on permanent, roomstat set to 19 degrees C turning it up to 21 when in, weekly usage was 47 cu mtrs gas, By using timers, 2hr in the morning, 6hrs evening, plus water, average 32 to 40 cu mtres per week,
So I came to the conclusion it was more cost effective to use timers, and advance heating if I came home early anytime.
I read my meters every week, and know when it is cold to expect higher usage.
just an observation, do what suits your lifestyle!
PP

 

[amyboo]

Heating comes on for an 1.5 hours on weekday mornings (21oC) - comes on 30 minutes before I have to get up so the flat is nice and warm. During the day it's set to 18.5oC, so the house never gets to cold. In the evenings it's on for 4 or 5 hours (21oC). On the weekends it's set to come on in the morning for a couple of hours, afternoon for a couple of hours, and then all evening.

We recently installed a thermostat timer when we replaced our boiler, and have it set to suit our routine - swimming 3 times a week after work means the heating comes on later. I don't see the point in heating the flat when we're not in it, but I always make sure the house is heated up before we get up or get home. Our heating system is pretty old (except the boiler), and takes a while to get warmed up. But once it's warmed up, our flat loses very little heat.

 

[roberta1000]

JohnD has it I'm afraid WoodYouLike, and there's plenty of scientific reasoning behind it. It is ALWAYS more expensive to keep something warm than to warm it up. You are suggesting that it is more efficient to keep the house at a certain minimum temperature than to let it fall below that point. (From that point upwards of course it is always the same).

Heat loss is proportional to the difference between inside and outside temperatures (we'll ignore minor condensation and similar effects). In you scenario the heat loss at your minimum temperature is constant for a given outside temperature so is proportional only to time. For JohnD's case the heat loss is the integral of time x differential and since the differential is constantly falling the integral is less than yours.

There are all sorts of arguments to do with comfort and how to get the house to be at a desired temperature when you get up / come in but the answer to the basic question is that it's more expensive to keep the house warm.

And what a surprise - not!