Not wishing to divert another thread, best to start a new one.
We have oil heating and it's costing a lot to run. Some internet sources say that leaving the heating on pretty well all the time in cold weather is better and cheaper, as the house isn't warmed from stone cold twice a day (which is what we currently do). We're out all day.
Anybody actually do this and does it really work?
Last edited by: Crankcase on Fri 7 Jan 11 at 10:33
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I use coal as fuel here, and keep the heating on lowish all the time. The lag time for increasing temperature to "normal" is small compared with that in raising it from cold, and it doesn't seem to make any difference to fuel consumption.
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I can't believe this makes sense.
Every house leaks heat to some extent. Therefore, the longer the heating is on the more energy is lost. It must be cheaper to heat it only when you're there, I would have thought, with maybe a lead-in period as a concession to your personal comfort.
That's what I do, anyway.
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We do that too, but the idea seems to be that the house acts a heat sink, to an extent. I've seen claims of a 20% reduction in oil consumption doing this, but as Chris says, it just doesn't feel right.
FT's experience is interesting in that consumption is not any worse and probably the house is more comfortable.
Hmmm.
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We normally have the heating on 6.30-8.30am and 4.30-10.30pm (modern gas boiler with rads, old solid walls house). When we are at home in the winter (2wks Christmas holiday for example) and leave the heating on all day it doubles the time period and the gas useage rises by at least 70%.
So for us pumping heat into the countryside when we're out doesn't make sense.
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For years we had a combi boiler because it heated water only when you needed it and that was its sales pitch.
We recently got a new boiler with the extension and it is a pressurised system boiler thingy , in other words back to a boiler and a hot water tank.
My plumber recommended that I kept the hot water on 24 hours as they were now designed with efficiencies that meant it better to keep topping up heat than starting from scratch.
Since November we have had our heating on 24/7 , just controlled by the thermostat in the hall.
At the time it all seemed "foreign" to my understanding especially in comparison to the sales pitch I had received for my combi all those years ago but I guess, relatively speaking, that is why many canteens and tea rooms will have an urn rather than boiling kettle from scratch each time?
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>> FT's experience is interesting in that consumption is not any worse and probably#
>> the house is more comfortable.
Don't forget that I'm using coal, not oil or gas. There are combustion issues, as well as heat loss issues. If I have the thing on full blast, the flue gets too hot to touch. If it's on low, it's not discernably warmer than the surroundings.
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>> I can't believe this makes sense.
>>
>> Every house leaks heat to some extent. Therefore, the longer the heating is on the
>> more energy is lost. It must be cheaper to heat it only when you're there,
>> I would have thought, with maybe a lead-in period as a concession to your personal
>> comfort.
>>
>> That's what I do, anyway.
>>
Spot on, this leaving the heating on 24/7 thing doesn't make sense for the reason you state.
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Howell is absolutely wrong with the hot water. It takes more energy to keep the water at "hot" than to let it cool and reheat it - because the heat leakage is greater the higher the temperature differential between the water and the outside. Moreover, for those who heat on Economy 7 he's wrong twice.
Makes you wonder about his advice on the heating the house point - his claim being that the condensation creeps through the wall and makes the house damp.
He certainly wrote some complete rubbish in the Telegraph about Part P's precluding your adding a socket to a ring main. I emailed him, he emailed back to say thanks, and a few weeks later a similar Q&A appeared with the correct answer.
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I suspect it depends on the building and its insulation. We have a 10 year old timber framed bungalow with well insulated walls, 300mm of insulation in the loft, and double glazing. The heating is by a gas thermal store boiler, it has an integral 50L tank as part of the heating circuit, and the domestic hot water supply is at mains pressure from a coil in this tank. all the radiators have TRV's fitted these are set at 3 in the lounge and 2 elsewhere, this maintains 20C throughout the house.
I have tried Heating on twice a day, morning and evening with a boost as required, for a winter period, and on all day for a winter unless we are out all day. I found the cost difference negligible and the heating stays on all day now. The hot water would be on all day anyway, the heating circulating pump is the heating on/off difference as the integral tank is hot for the hot water.
Our radiators are often cool or cold even though the house is at normal temperature.
Last edited by: Old Navy on Fri 7 Jan 11 at 13:00
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It will only save money if you turn down the output of the boiler and have a thermostat. You generally need a higher setting to get it to warm up the house to the required temperature within a shorter space of time. The house will lose heat but the idea is to balance the heat losses and the heat inputs. If you are bringing the temperature up it takes more fuel to do this than maintaining a constant temperature. It works best if you have a thermostat somewhere as you can turn it up or down so that it will maintain a lower temperature while you're out without letting it get too cold.
Radiators can hold a decent amount of heat so even having the heating ticking on every hour for a bit would keep the house warmer and probably cost a lot less than having several hours on full blast.
Best way is to try it and see. Monitor use for a week. Then turn it on constant for the week after and see whether you use that much more. Getting your oil boiler serviced will probably save you the most money. Followed by lots of insulation and draught excluding. Oh, and plenty of jumpers :)
I find in some weather it is better to warm up from cold, especially if it is a sunny day but if it is overcast and cold leaving it on low means the house stays warmer and the boiler doesn't fire that often.
I have used both methods over the years and I can't honestly say the gas usage has been noticeably different between the two.
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I leave the central heating (combi-boiler) on permanently, but turn the temperature dial down a little at night (occasional boiler activity prevents the condensate pipe from freezing up and also saves energy by not having to re-heat the property next day).
It just doesn't make sense to re-heat a property from cold throughout the winter; think just how low a simmer setting is required to keep a pan of water at boiling point, especially if the lid is used.
My fully insulated Victorian property, in fact, proves to be the equivalent of the pan lid, retaining as much of the heat as possible.
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>>>It just doesn't make sense to re-heat a property from cold throughout the winter.
Well it does with ours or gas consumption rises by 70% for the days we leave the heating on all day.
Our place is effectively of Victorian construction with no wall cavities and is in a very exposed position... so it can't not leak much of the heat put into it. Also with double glazing/doors you need to keep the place ventilated which loses heat.
Last edited by: Fenlander on Fri 7 Jan 11 at 13:12
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Shirley it all comes down to the energy performance of your particular dwelling.
The ancient submariners modern bungalow is obviously 'state of the art' as regards to energy efficiency whereas my 1930 jobbie with its solid walls and 11 year old broiler is quite poor.
I did leave the heating on from 6am to 9pm during the ice age and it did in fact fire up much less once the house warmed up nicely but - I would hazard a guess that I would be in the same boat as Fenlander if I kept the heating on all day, so I sit here in 15°C, which is 5° above the external temp without any heating whatsoever.
Regarding Crankcases remark about the house acting as a heatsink, my walls are 1 foot fick and they indeed retain heat to some extent and hence act akin to a storage rad in a way, but to heat those very walls from stone cold twice a day is probably less-than ideal me thinks.
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Our house seems to retain alot of heat being only 25 years old and fully insulated, so with our year old combi, its made more sense in terms of units used to keep the heating on. On days that its 5c outside, its hardly ever on such is the retention of heat.
Last winter we only had it on when we were in and it cost a fortune, so we changed tack this year and a glance at the gas meter suggests constant is the way to go in this house.
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I've heard this argument many times before, but I've never seen proof.
The laws of physics must mean it's a load of old cobblers.
The only reason you have heat in a house is to replace the heat that's lost to the outside. The greater the heat differential between the inside and the outside, the greater the rate of loss of heat and therefore the greater the amount of fuel required to maintain the inside temperature.
Unless anyone can prove otherwise.........
As an analogy, would you keep a kettle boiling permanently for the various occasions you require boiling water, or would you heat the water from cold?
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There are devices on the maket which do this, delivering boiling (filtered) water to a tap fitted over your kitchen sink. I'm thinking of getting one as part of my current kitchen refit project. Well, the wife is.
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A colleague lived in an old house that had enormous fuel bills. He tried all forms of insulation to reduce the bills and they worked to a degree.
It wasn't until his wife commented one day, how convenient it was to have hot water the moment you turned on the kitchen hot tap instead of waiting for it to flow. He'd never noticed before.
He found the house was fitted with a system that pumped hot water in a loop from the hot water cylinder to the kitchen and back to the cylinder. He removed it and saved a fortune.
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Depends what the rate of heat loss is. The amount of gas used is determined by how long the boiler needs to be on. If heat is pouring out of your house, the needs will be far greater.
From a cold house ( 13c ), mine needs to be on 2 hours to heat the house up. Ive been home for 4 hours and the house is maintaining 21c without the boiler so far.
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>>If heat is pouring out of your house, the needs will be far greater.
Agreed. You can never achieve perfect insulation, but however much insulation you have there will still be a loss of heat.
I still stand by my statement:
The only reason you have heat in a house is to replace the heat that's lost to the outside. The greater the heat differential between the inside and the outside, the greater the rate of loss of heat and therefore the greater the amount of fuel required to maintain the inside temperature.
Would you leave the heating on to save money if you went on a fortnights Winter holiday?
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Yes I would, at a very low setting, to preclude burst pipes! I went away for 6 days before Christmas and left the heating off. When I got home (well insulated semi with people living next door heating the party wall) and the temp in my lounge was +6C. Just warmer than my fridge! When I next went away I left on continuous and the stst set to +10C. I don't think the boiler came on once although I have no way of knowing. Next time I will read the meter before I go. Overall I agree with BT's thoughts on this.
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Any decent central heating system will activate, even if basically turned off, when the temperature falls below +5 degrees C.
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>> The laws of physics must mean it's a load of old cobblers.
>>
Good executive summary there :-)
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If you have a party with say 100 people it'll be so hot you'll need to open all the windows. Communal living - that's the answer.
By the way, when my dad was lad and living on a smallholding / farm the entire family slept on a mezzanine floor above the animals to keep warm. Must have been a bit smelly.
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...Must have been a bit smelly...
I'm sure the animals got used to it.
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In the olden days the family slept in the same room as the livestock,
The welsh of course took this a little too far.
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and londoners are still trying to buy into it
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Ok, further to my previous note saying that since I got my new boiler, I keep hot water on 24 hours a day and central heating the same, albeit thermostatically controlled.
Have just received my NPower bill for the period 16 Oct to 9 Jan, 86 days and in that period I have used 9668Kwh or 851 cubic metres.
Total gas bill £297.70 which equates to £3.46 per day.
This is for a 2 living rooms, 3 bedroom, 3 bathroom , utility room and kitchen "modern" house. Both showers run from the hot water system and 4 showers a day taken.
I also have a modern gas fire in one room which may be used a couple of times a week.
Also bearing in mind that this has been a very cold period.
I initially thought the bill to be high, but to get heating, washed etc for the price of a pint in some pubs, I am beginning to think is maybe not too bad?
Thoughts?
Last edited by: BobbyG on Wed 12 Jan 11 at 09:18
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My parents live in a similar size modern house. They have the heating on timed but boost it in the day now and again as needed... they are retired and at home much of the time.
Their bill for a similar period is just under £200 but I guess they use the shower far less.
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Any figures from previous same period? (usage not cost)
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good thinking smokie - will check my records when I get home!
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Our gas bill last year which covered the cold period was for 3 months £220. Thats 3 bed det, 1 bath and open plan living dining room ( I say that because open plan houses not so easy to heat ).
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I installed a programmable room thermostat years ago and left the heating on constantly with a 'profile' of 6 different time-periods during the day.
I'm not sure whether this was merely a convenience (rarely having to touch the thermostat) or saved me money, I suspect that it actually did. By running at a low temperature (14DegC IIRC) overnight or when we were out during the day the house never got too cold. I also found that you could run a degree or so lower than with a manual system and wonder whether this has something to do with the perception of temperature without the large variations. The house was well insulated but of 1930s construction and my bills definitely dropped.
Eventually we also had a mains pressure hot water system fitted with a large tank and this only needed to be run for 2 hours a day to provide a constant supply of hot water at fantastic pressure, I'd never go back to a combination or gravity fed system if I could avoid it.
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BobbyG's broadly £100 a month for gas bills compares with my broadly £120 a month for oil, and our old house is anything but well insulated (and is impractical/too expensive to improve further than we have).
Of course, his are for the cold period and mine is annualised, so it's costing me that in the summer as well.
So perhaps my bills, which is I why I started this thread, are not so far off the mark after all, although we do have to accept being cold most of the time unfortunately.
Last edited by: Crankcase on Wed 12 Jan 11 at 12:37
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>> Put on another jumper.
We wear so many jumpers we can't put our arms down. Seriously, Mrs C, who is a cold morsel, wears TWO Berghaus mountain fleeces, one on top of the other, and still complains.
We'll have to move is all.
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I won't keep the heating on - I like being warm but I also like to balance my sort of heat dependence, I generally find central heating use can be quite stifling - the temperature in the south facing side of the house is currently 15.5 C (according to the Owl electricity monitor) which is plenty warm enough. I can't see the point of running the boiler to maintain this when nature does it itself...Not subject to many colds ever so this formula must be right.
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My gas bill is 59 pounds a month annualised.
Thats for central heating and a gas hob.
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Looks like I have some way to go to match yours Zero?
When do you take your annual bath? :)
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>>
>>
>> As an analogy, would you keep a kettle boiling permanently for the various occasions you
>> require boiling water, or would you heat the water from cold?
>>
I keep it just short of simmering half on the Rayburn hotplate, and then move it fully onto the plate when I want to bring it right up to the boil to make tea.
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OK, might as well resurrect an old thread.
Being the sad anorak I am, I have monitored my gas usage over 2 weeks. One week, I kept the hot water and central heating on 24/7 controlled by thermostat. The second week, I had both HW and CH on timers, only coming on for a few hours in the morning and evening.
For the week that I had both on 24/7, I used 46 units.
For the week of timed settings, I used 69 units.
Coincidentaly, exactly 50% more gas used by having the boiler on timers than having it on 24/7.
Obviously this can only relate to my specific boiler / tank set up though but until the better weather comes in and the heating is totally switched on, then I will be keeping both on 24/7 !
Thoughts?
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What were the temperatures in each week?
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This winter from Oct- Jan I had the heating on 21c night and day doing the same experiment. The bill was £10 more than having it on timer but bearing in mind that the cold came earlier than the previous year whose bill I can compare it to, id tend to agree with Bobbys findings.
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In the nature of experiment I have just switched our heating to remain on, rather than kick in tomorrow morning. I fully expect Mrs C will complain about the ticking of the pipes all night, but we'll see. I'll leave it a week and see what happens...
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I think the problem is heating up all the hot water and the house in one go first thing in the morning, thats the real fuel killer.
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I found that having the heating on in all the rooms seemed to help the building maintain heat.
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Someone did mention about the house acting akin to a storage rad, so once it's warmed up - providing it's well insulated, it will retain the heat, where as heating the house from stone cold twice a day could well be an inefficient use of energy,
as your test has shown.
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I couldn't be doing with it hot in the house at night. I like my feet sticking out and the curtains and window open at the best of times.
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>>and the curtains and window open at the best of times<<
Same here, but at all times.
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Moi aussi...window open all through the year...about 6ft from my pillow.
Nice when you get a breeze through and you're all snug.
Ted
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>>Our place is effectively of Victorian construction with no wall cavities..>>
My property is mid-1880s, does have cavity walls and is fully insulated, including the loft.
In 2009, for various reasons, the property was not occupied very much during the day and the central heating was on a timed basis but, this winter, it has been occupied throughout the majority of each day and the central heating left on permanently.
I'm on StayWarm and received the price for the new contract the other day. It revealed that this winter both gas and electricity usage are down by approximately one-fifth and the renewal contract is for the same price as the outgoing contract (most likely due to fuel price increases in recent times).
It proves to me, at least, that keeping the central heating on permanently, turning it down two or three degrees overnight, is far more economical than having to heat up the property each morning.
Ironically, a check on uSwitch revealed I could save around £255 annually on the current consumption figures if I switch (E-On came up with £170 for switching tariffs), but doing so would mean I couldn't go back on StayWarm.
I'd rather pay a bit more and have the comfort of not having to worry too much about gas and electricity consumption in bad winters on the lines of the last two we've experienced.
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>> My property is mid-1880s, does have cavity walls
That's interesting - have you a picture of a part of the outside you could upload somewhere?
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My property is mid-1930's and is single 9" block, the heating is on for just 2 hours in the morning and 4 hours at night, I feel sure that if I put the heating on say from 6am to 10pm my heating bill would soar.
I have 10 inches (in the loft)
Last edited by: Dog on Wed 16 Mar 11 at 12:38
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>>That's interesting - have you a picture of a part of the outside you could upload somewhere?>>
I live in a Victorian seaside resort and a large number of the properties here of that era have cavity walls, along with 11ft or 14ft high ceilings depending on the area.
Like most of them, mine is Acrrington brick at the front and stock brick for the remainder of the property.
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Cavity walls were introduced in the nineteenth century, originally in Ireland, to stop the penetration of windblown rain, particularly in coastal areas. Became the norm. after WW1
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No picture? It needn't give anything away - just a decent sized area of blank wall would be ideal.
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>>It needn't give anything away - just a decent sized area of blank wall would be ideal.>>
No means of posting a photo as it's something I've never needed to do (normally e-mail them to friends and family!)
Are you not aware of what Accrington and stock bricks look like?...:-)
Took nearly three hours for the insulation company to do the cavity wall insulation work about five years ago. When we had the double-glazing installed in 2001 the fitter (also a top class joiner) made wood shelves to both bridge the cavity gap and create a display area in the front room bay windows.
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>> No means of posting a photo as it's something I've never needed to do (normally
>> e-mail them to friends and family!)
>>
There's the opportunity for you to try out something new on t'ineternet.
>>It needn't give anything away - just a decent sized area of blank wall would be ideal.
>>
or, how about a streetview link to a similar street to yours.
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>>or, how about a streetview link to a similar street to yours.>>
53°39'08.41" N 2°58'20.75" W
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The amount of heat lost from the building to the outside is, at any one time, proportional to the temperature difference between the building and the outside ambient temperature. If the heating is on constantly the temperature of the building is constantly higher than it would be at times when the heating could be off. The more heat that is lost the more heat is required to replace it. Consequently, keeping the heat on all the time costs more. However, the effect on the comfort level of keeping the heat on all the time is a different matter.
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It will be interesting to see (and feel) the difference between new build and old when we move into an 18th century cottage with over 2ft fick solid granite walls some time soon (we hope)
Ze cottage has been extended in the last 4 years, so about 40% of sed cott is block-cavity- block, then faced in granite to match existing 18th century building.
From previous experience I've found the old solid cob or granite cottages to *feel* warmer.
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...I've found the old solid cob or granite cottages to *feel* warmer...
Low ceilings, less air mass to warm perhaps?
Iffy Towers is Victorian with high ceilings and is never cosy warm, no matter how much heat I punch into the building.
Unless I keep the open fire going for hours on end.
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>>Low ceilings, less air mass to warm perhaps?<<
Yes, that could explain it, the 1930's place we're in at the moment has 9ft high ceilings and single 9" block walls, but it's certainly a lot warmer (heat retaining) than our last place built in the 50's with lower ceilings & cavity walls.
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>> Iffy Towers is Victorian with high ceilings and is never cosy warm, no matter how
>> much heat I punch into the building.
>>
Gentle air recirc fans at ceiling height, that's your solution. Your comfort levels will improve and your heating bills will go down.
www.green-energy-efficient-homes.com/ceiling-mount-fans.html#Choosing_a_ceiling_mount_fan_-_mounting
Last edited by: John H on Wed 16 Mar 11 at 19:03
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...Gentle air recirc fans at ceiling height, that's your solution...
I'd not thought of that, but it makes sense.
There's an enormous ceiling rose in the lounge, so a fan underneath would like quite well.
I've got an oh-so-stylish paper 'puff ball' shade at the moment.
Rarely use the centre light, prefer a couple of floorstanders.
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>> Consequently, keeping the heat on all the time costs more.
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Unless you have the system BobbyG has. His seems to waste a lot of energy on start up from cold.
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OK, have now completed my analysis of the various settings. Each has been monitored on a Tues to Tues, but obviously need to take into account that it is also getting milder.
Week 1: 46 units gas - Hot Water and Central Heating on 24/7
Week 2 : 69 units gas - HW on timer, CH on timer, both on/off twice a day
Week 3 : 48 units gas - Hot Water and Central Heating on 24/7
Week 4 : 39 units gas - HW on 24/7, CH on timer
So the last week was the most efficient and that was keeping hot water on all time and just flicking CH on for morning and evening. It certainly looks like the boiler and hot water tank is more efficient by only having to top up the temperature rather than starting from scratch.
So that finishes my detailed research!! I will collect my doctorate later .... :)
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>> So the last week was the most efficient
More importantly, consumption was 40% higher with both HW/CH on timer than when both were left on permanently (Week2 vs. Weeks 1/3). Interesting...
To validate the "experiment", I'd want average outside temperatures for the weeks in question.
Last edited by: Dave_TDCi {P} on Tue 29 Mar 11 at 22:25
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It's been really warm though, the last week - my central heating has been off and the temperature has stabilised at 17.5 degrees inside.
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Overnight temperatures here (Leics) have still been down to, or just below, freezing this week. I put my central heating on from 0630-0830 on schooldays which warms the house up from 15C to around 20C, but this week I haven't used it in the evenings because of the solar gain through the day and the warmth generated by cooking dinner. I shut the curtains at dusk and tuck them onto the window sills to expose the radiators and the living room stays above 18C until at least 10pm.
I have a real interest in saving energy as I'm on pre-payment card meters for both gas and electricity.
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what about the results for ch 24/7 - hw on timer?
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>>what about the results for ch 24/7 - hw on timer?<<
There always has to be one, doesn't there :-D
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Keep the heating on permanently? - FotheringtonTomas
