A few degrees difference can make a surprising difference in heat loss. If his house is warmer than yours there will be a heat loss in the party wall, too - and the heat coming through will be reducing your bills...
On 05/11/2012 09:42, David WE Roberts wrote: ...
Calculating for air conditioning, we used to allow 60W each for adults working in an office.
Colin Bignell
Years ago, we had a shop. There was a flat upstairs, and when the tenant moved out, we took on the flat. We then discovered why our shop bills were so high - the major appliances upstairs, were all run off the shop's electrical service.
The point is here that it is only 5mm thick the absolute numbers are
Glass ~ 1 W/m/K Steel ~ 60 W/m/K
But the point is that 5mm is 1/200 of metre so the absolute values for a 5mm sheet of either are 5mW/K and 60mW/K or put another way the temperature difference across a window pane is 12x bigger for glass than for steel but it is still small compared to the temperature difference between inside and out. Enough heat flows to be a nuisance.
Basically with both you get cold air running down the inside of the window and warmed air running up the outside. There are slight differences in the temperatures but the net heat loss is similar.
Air has a low heat capacity so the amount of heat passing though the single glass sheet is already enough to power convection.
Everything changes if you close a decent set of thick curtains and trap the cold air against the window. But again steel or glass makes little difference to the total loss it is limited by the heat capacity of the convective air flow inside the room.
If you look at insulators you will find they are an order of magnitude or two different as well.
So on a log scale 'not far off' is reasonable :-)
Add another 15+ years! Still getting around, driving and coping on his own though.
I do wonder whether this is the issue but he's using huge amounts of gas as well as more electricity. Since his cooker is electric, there's really only hot water and heating on the gas.
We're rarely in so it's not that :-).
There were a few things worth checking from other users such as any windows which don't close properly but he's pretty good about getting things fixed and he's fully double glazed. Perhaps in the future, there will be "mini-meters" on each device so we can see where the power is going! That's almost possible with electricity and one of those nice monitoring devices, but it's harder with gas.
Paul DS.
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TurNiP never lets facts get in the way of his theories.
Not sure if anyone has mentioned open fireplaces. These can (under the right/wrong conditions) carry an awful lot of warm air up the chimney to the outside.
To really cut down on heating bills he could select one room as his main living area and turn the TRVs down on all the radiators in the other rooms. Ideally have a wireless thermostat which he carries around with him so only the room he is in is up to temperature (requires turning TRVs up and down as he changes rooms). As gas useage is high targetting where he heats (I assume he seals off all the bedrooms he doesn't use and keeps the TRVs on frost protection) could reduce the overall bill a lot.
Probably (as stated elsewhere) a combination of higher ambient temperature and longer time of occupation during the day will account for mch of the extra energy use.
Cheers
Dave R
although some are not as bright as that ...
One way to get old people warm is to tweak the perceived or reported temperature.
A dodgy thermometer where the scale has bee moved can work, as can a dummy thermostat they can endlessly twiddle with, also moving the dial scale around on a thermostat can work but many just use it as a rotary on off control and just listen for the click. A slightly more high tech solution is altering the offset of a programmable thermostat so that the display says 18 deg C but in reality it is maintaining say 22 deg C. Honeywell programmable thermostats used to offer this hidden setting but not sure if they still do.
Cats must be pretty good too.
Not sure how many kittywatthours you get per tin of whiskas though.
Owain
Cats are primarily local heating devices, usually on my hip and / or feet when in bed.
Colin Bignell
TRVs? Wireless? He's 92 and although he went tv-digital early there are limits. Were it me I'd be "speculating to accumulate" but he has a limited budget and, with greatest respect to all elderly readers, limited time to recoup any investment.
But a very good reminder about shutting doors. I'll bet he doesn't - will check tonight.
Paul DS.
Does he leave the heating on at night?
Robert
Hmmm....lack of TRVs could go a long way to explaining the extra heating use. Especially in a good sized semi.. You need to be able to limit the heat wasted in rooms not currently in use.
He claims not. That said, his home always feels warm to me so perhaps he does and doesn't realise it. Must ask him to show me how it works.
Paul DS.
too - and the heat coming through will be reducing your bills...
We used to live in a 1970-built semi, which wasn't very warm (single glazing, 1cm loft insulation, cast iron based gas fired back boiler), then one year our attached neighbour sold their house to a builder as part of a new house purchase.
The four months the house was empty were the winter months, and our house was noticeably cooler. Once new neighbours moved in, winter temperatures reverted to normal.
Terry Fields
Around a year ago, we bought a new cooker. And that has been of obvious benefit to our electricity bill. Indeed, in the summer, it was of obvious benefit to anyone in the kitchen! I wonder whether that would make a significant difference? You know - if he always turns on a large, poorly insulated oven, and pre-heats for an inordinate time, etc.
And I know my mother habitually turns the burners up on hers and would rather boil away a pint of water than a) use less water; b) turn the burner down to a simmer rather than a raging boil.
Also, she fills her kettle with at least twice as much liquid as it actually needs.
These are not wholly out of lack of awareness - but it seems ingrained in a way that simply cannot be changed.
On the kettle issue, seen that, plus another one where the kettle is immediately overfilled and boiled again...despite it being right next to a now brimming teapot ready for pouring. The kettle then sits cooling for an hour or two before the cycle begins again. Last thing at night the kettle is boiled and sits there until next morning.
Leaving the fridge door open is another one, the period of time the warning beep has sounded for must be in the hundreds of hours!
Reluctance to insulate the loft yet double glazing changed every five years
Leaving the back door open to get some fresh air in the house when its sub zero outside
Similarly with windows upstairs, bedrooms and bathroom chilled with a through flow as radiators struggle to maintain the temperature above freezing
Leaving back door wide open when taking things to the dustbin or hanging out washing
Some people are untrainable.
Where I worked in California, the campus had a large expanse of grass, which in summer normally was watered. A memo came round to all staff, saying that as there was a drought, this watering would cease, and would people please conserve water. This was discussed by folks so there was no likelihood that some had not seen it.
Within two hours, one chap had turned on the tap at the little sink where we made coffee, and then turned around to talk to me. I suggested he turn it off. "Oh", he said.
Another chap brushed his teeth in the toilets after lunch daily (well in the washbasin actually :-) - fair enough, but he had the water in the sink turned on full blast during this whole process from beginning to end. At 3 bar or so that was a lot of water. Every day.
Tim Streater :
Why do people turn the tap on when they start cleaning their teeth? I wait until I've finished brushing.
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