Heating regime and the gas

[woodbloke]

Now that the colder weather is here, we're tending this winter to put the heating on as and when it's needed, rather than setting the timer clock so it comes on twice a day, as we did last year. So far we haven't had it on in the morning and just flash up the boiler later on in the evening when we settle down for a bit of telly. With the hike in energy prices I'm hoping that we'll be a little more economical with the gas than we were in the past. Anyone doing anything similar, or are you getting the duvets out for the sofa in the evening? - Rob

 

[Paul.J]

Doesn't it cost more using the heating that way,as the whole house as to heat up again,using more gas :?: :?

 

[Raggy]

Doesn't it cost more using the heating that way,as the whole house as to heat up again,using more gas :?: :?

Thats the way I understand it, we generally leave ours on all the time and just alter the thermostat as and when needed. Turn it down at night and up little by little as it gets colder during the day.

 

[MikeG.]

I can bore for England on this subject!

The most efficient heating regime depends upon the thermal mass of your house, and of course, the amount of insulation. A lightweight well insulated house will have an entirely different heating requirement to a heavyweight well insulated house......althought the net heat-loss over the year may well be the same.

As an experiment, 10 years ago I built 2 houses side by side: one of them a super-insulated double-stud construction timber frame house, the other a super-insulated heavyweight house with an external timber frame. Both have triple glazing, a whole house ventilation system with heat recovery, and have "airlocks" (porches, conservatories etc) over the external doors.

The lightweight house costs about £70 per year to heat, and the heavyweight one, where I still live, costs about £40. Both maintain constant internal temperatures of around 21 degrees year round and through the day and night (although the lightweight one has a tendency to overheat in the summer). The heavyweght house has never lost a degree in heat over 24 hours, whatever the wether, without the heating on.

The earliest the heating has ever come on in the heavyweight house is mid November, and it generally turns itself off finally in early April. Neither house has heating upstairs, and neither need it.

My point.......I am getting to it!!!......is that the heavyweight house has less insulation than the lightweight one, and yet is clearly more efficient. Thermal mass within the insulated envelope is the key. There are a number of houses in the UK with no central heating requirement at all..........just a woodburning stove for the coldest days.....yet maintaining internal temperatures of 20 or 21 degrees. It can be done..........so long as we don't just build the way our dads did, or to the minimum requirements of the Building Regulations.

Anybody awake still?

Mike

 

[OLD]

I use a programable thermostat that controls the circulating pump you set the temp for a number of times during 24hrs so you maintain those settings all year if you like it also has a week end setting to set new times and temps. you can press a button to raise or lower temp manually.

 

[Paul Chapman]

we're tending this winter to put the heating on as and when it's needed

That's how we do it, Rob. We also have an open fire in the lounge which is nice - if gas and electricity prices go up too much, we're planning to live in the lounge :lol:

Cheers :wink:

Paul

 

[andycktm]

Double last years bill and add 25% just to be sure :shock:

 

[wizer]

Our house looses lots of heat. I know I should insulate the loft and I know I should replace the double glazing and I know I should insulate the garage roof, but I can afford to. So our heating is full blast (24-26 degrees) from about 17:00 round to about 7am the next day. During the day I keep the thermostat on about 22c which means it comes on and off sporadically during the day.

I always thought it was better to keep the house at a constant temp rather than to blast it in bursts. Something like it takes more energy to heat a whole house than to raise the temp by a degree or 2.

 

[wizer]

My missus was yapping on about turning rads off in rooms we don't use so often, but I'm not sure how much sense this makes. If a room is stone cold, then surely that cold air will effect the efficiency of the heating system?

 

[woodbloke]

Anybody awake still?

Mike

Mike - you've lost me, completely over the top :? So is it better to have the heat on low constantly and tweak it up as and when or to flash up the boiler in the evening when the temp drops? The house is a standard brick cavity wall construction with dg and about 300mm fg in the loft but all the rads downstairs are double panel and it gets very toasty, also bearing in mind that it's empty all day during the working week. - Rob

 

[Philly]

Mike
Very interesting! Any links to more info on these house types?
Cheers
Philly

 

[busy builder]

Well we don't have gas, only oil where I live up in the Highlands of Scotland. Last time we filled up it was 51ppl plus VAT, then it was upto over 70ppl now its back down to 46ppl so the wifes topping up again.
Not sure how oil stacks up against gas though.
We also leave the heating on low all the time and use the multifuel which is toasty and the wood is carbon neutral but best of all FREE !!

 

[motownmartin]

I use a programable thermostat that controls the circulating pump you set the temp for a number of times during 24hrs so you maintain those settings all year if you like it also has a week end setting to set new times and temps. you can press a button to raise or lower temp manually.

I have just fitted the same but don't know yet how much it will save me.

 

[motownmartin]

Doesn't it cost more using the heating that way,as the whole house as to heat up again,using more gas :?: :?

Not sure about the logic here, its like saying I leave my cooker on all the time so it doesn't have to heat up next time I use it.

 

[Dave S]

At the end of the day, the longer you have the heating on, the hotter you heat it and the more rooms that you heat, the more energy you will use.

So Paul, no, it will not cost more if you do as Rob is.

Tom - sounds like your neighbours are probably warm and toasty just from your waste heat! 24-26degrees??!!! :shock: You walking about in shorts? No wonder your workshop feels so cold!

Yer missus was yapping correct, by the way. :wink:

The crucial thing to remember is that the higher the temperature inside, the greater the rate at which heat is lost to the outside. The worse the insulation, the greater the rate at which heat is lost. That is why lowering the temperature (or further still, leaving the heating off as Rob is doing) will result in much less wasted heat and hence significant cost savings.

Dave

 

[motownmartin]

At the end of the day, the longer you have the heating on, the hotter you heat it and the more rooms that you heat, the more energy you will use.

So Paul, no, it will not cost more if you do as Rob is.

Tom - sounds like your neighbours are probably warm and toasty just from your waste heat! 24-26degrees??!!! :shock: You walking about in shorts? No wonder your workshop feels so cold!

Yer missus was yapping correct, by the way. :wink:

The crucial thing to remember is that the higher the temperature inside, the greater the rate at which heat is lost to the outside. The worse the insulation, the greater the rate at which heat is lost. That is why lowering the temperature (or further still, leaving the heating off as Rob is doing) will result in much less wasted heat and hence significant cost savings.

Dave

Sounds about right to me

 

[andycktm]

Only one important thing to remember, be prepared to be shocked when the old gas bill arrives.

Gas is tied to oil when oil price goes up,but when oil price goes down eerrrrrr.

 

[MikeG.]

Mike
Very interesting! Any links to more info on these house types?
Cheers
Philly

Philly,

unfortunately, I have only published the results of the studies of these houses in a couple of academic articles, written in boring language on paper.......so no links I'm afraid. Sorry!

Mike

 

[MikeG.]

Anybody awake still?

Mike

Mike - you've lost me, completely over the top :? So is it better to have the heat on low constantly and tweak it up as and when or to flash up the boiler in the evening when the temp drops? The house is a standard brick cavity wall construction with dg and about 300mm fg in the loft but all the rads downstairs are double panel and it gets very toasty, also bearing in mind that it's empty all day during the working week. - Rob

A nice analogy is the kettle. To save energy, would you leave the kettle simmering constantly, or just turn it on when required?...........The answer is more complex with a house, of course, because some houses (lightweight, well-insulated ones) respond really quickly to heat inputs.....like the kettle.

Some other houses, mine included, respond really slowly on account of their heavyweight structure and external insulation. Think of these as a really heavy flywheel, that take a lot of energy to get turning, but once they are spinning require only the occasional drip of energy input to keep the wheel going. (The "lots of energy to get turning" in the case of my house comes from the summer warmth and a south-facing conservatory).

A typical brick and block cavity wall insulated & double glazed house in the UK is going to be far too lightweight (and poorly insulated) to benefit from the flywheel effect descibed.........but will respond fairly quickly to heat inputs. Therefore, heat it just before you need it to be warm. Anything else is wasted.

My heavyweight house uses the equivalent of 4 light bulbs left on 24 hours a day for the 4 months of the heating season to stay warm. Oh, and thatched roof apart, cost about the same as a conventional house to build.......

I told you I could bore for England on this.....

Mike

 

[Jake]

What's the 'heavyweight' part of it then, Mike?