Energy myth-busting: Is it cheaper to have heating on all day?

Cardew

bestyman wrote: »

By "shut off ", I do not mean suddenly shut off instantly. if set to 20, they may start shutting off gradually at 18, 19 or even 17, but this is irrelevant.

I agree with the thrust of your post, however the discussion really was kicked off by this statement of yours, which is at odds with the quote above:

If you set a rad valve to number 3 which is say 20 C, the rad valve will be fully open until the room air temp gets to 20c, at which point it shuts off.

(my bold)

orrery

bestyman wrote: »

The original MSE statement which said
Your room thermostat only switches your heating off when the set temperature has been achieved, so turning your thermostatic radiator valves down will mean your radiators will not get as hot and will gently heat your home to the set temperature.
is 100% incorrect.

It is misleading but it isn't 100% incorrect at all. As the room approaches the set temperature, the rad will be throttled back. This 'throttling back' process may well commence several degrees before the desired temperature is reached and will give rise to the effect they describe. So, (assuming the room starts from cold) early on in the heating process the effect will be as you describe - full heating, but long before the set point is reached the rad temperature will taper off and may significantly extend the time taken to reach the set point, and in some cases prevent the room from ever reaching its set point.

Joe Public appears to be pathologically incapable of understanding thermostatic control and this over-simplification that you criticise is regrettable, but probably necessary.

vm2pensioner

Yes, it's like when weather reports say "you'll have to turn up the thermostat as cold weather is coming" If the thermostat is working correctly, it should regulate the temperature accordingly!

orrery

vm2pensioner wrote: »

Yes, it's like when weather reports say "you'll have to turn up the thermostat as cold weather is coming" If the thermostat is working correctly, it should regulate the temperature accordingly!

Indeed. Your point is key to the current discussion on thermostatic radiator valves where there is some justification for increasing the setting slightly in winter over the summer setting.

John_Pierpoint

To a small extent the temperature needs to be higher in cold weather, especially if the home has a 9" solid wall and single glazed windows. We have all had that experience of being next to a cold wall or a window without the curtains drawn and both seem to radiate cold. They don't but our perception of comfort is dependant on the heat we feel radiating towards us less the heat we are radiating towards the garden. Next to a large un-curtained window there will be little coming back into the room on a cold night.

Typical Victorian end of terrace house with a no entry sign on the corner of the street.

mycar37

I've been reading all this nonsense about central heating and how long it takes to heat up the room/house. I have warm-air central heating and it takes 5 mins max to heat the house when we come back from being out or away. The heat is always off at night - good duvet but is set to come on every morning. With regard to MSE's Cheap Energy Club I wonder why the option to compare gas/electricity separately is not provided. It can make a difference.

John_Pierpoint

May I ask about the structure of your home?
If you could find a picture of a similar house on Google. that would help me to understand your posting.

waqasahmed

Just seen that our flat is C rated for efficiency and B rated for carbon emissions Currently our flat is at 79, with a potential for 80, and our carbon is at 85, with a potential for 86

Reading the document, it says that the recommended measures are to install low energy lighting for ALL fixed outlets. Aside from the bathroom, all rooms in the house now have low power lights. Three rooms have LED lighting, and I've ordered a couple more LED bulbs, to make sure that the other two rooms have LED lighting as well,

Which just leaves the bathroom light, which I can't take off

At the end of the contract, I'll take my LED lights with me

I've also decided to put some Asda foil behind most of the radiators. I know it's not as good as say Radflek, but we're only here for a year, so I don't really want to pay a lot, for something that itself takes around a year on a standard house to pay back, and this isn't a "standard house" considering that it's a pretty well insulated small second floor flat, with all the radiators facing internal walls

malc_b

mycar37 wrote: »

I've been reading all this nonsense about central heating and how long it takes to heat up the room/house. I have warm-air central heating and it takes 5 mins max to heat the house when we come back from being out or away.

It might take 5 min to heat the air, when you're standing in front of it. Turn the question around. Inside of the your house is at 20C, outside at 0C. You turn the heating off and go to bed. 8hrs later you get up and the house is at 10C, say. So over night the temperature has slowly dropped from 20 to 10C. That energy has leaked out of your house. So where has it come from? You turned the heating off. It has to have come from the walls of the house. You have to make up that energy when the heating is on. It can't leak out each night without you replacing it during the day. And there must be energy stored in the house walls because if there is a temperature difference, inside to outside, then energy must be flowing out all through the night. If the storage was zero then the instant you turned off the heating the inside temperature would be the same the outside.

adrenalin

I like sleeping in cold big 13.5 tog duvet, it about 16-17c if 0-2c outside in here due a grade windows and ok loft insulation could be thicker, 1st floor flat purpose built 4 flats, i share no walls just on corridor and just floor. I wake up put central heating 30 mins to 23c last 14 hrs goes to 18c. Id never leave on it depends property i think. If have leaky big house best leave on low i think.

In -5 i may put on twice in day lol

Last year before council put in windows i had it on a lot more. I hoping save money this year

acually some days if 18c i dont bother with heating if warmer out

1991 1 bed flat