How many degrees does your property lose overnight? (2024)

With our new Honeywell thermostat located well away from rad's, we now monitor the inside temp. first thing upon coming downstairs (7 or 7.30 ish) and outside on the utility wall thermometer. C/heating goes off about 8 o'clock the previous evening and room 'stat is set for 19 degrees. This morning it was 1.5 outside and 13.5 inside, the lowest yet! That means a loss of 5.5 degrees overnight in the living room for the 11 hour-ish duration.

This seemed a big drop, but the bitter E-N-E wind is obv. taking heat away from this cavity-walled 3 bed detached. Made me wonder how insulated we really were ! I wonder if those of you with gas-fired heating and easily monitorable thermostats are aware of how much heat loss your property suffers overnight. Last night was exceptional because of the wind chill and lower temp., as recently we've had roughly a 4 degree drop overnight with less wind and 3 to 4 degrees outside.

My sister and husband keep their 'stat on 21 degrees 24/7, which many (and I) think wasteful, but we always sleep with a slightly open window anyway Any thoughts?

Too many variables I think, it's not linear. The colder it is the more it loses. I came home from work just now and the dining room was 11c, it will probably take all evening to reach 17 and it will be about 12-13 I'd guess when I get up around 6.

There's no point turning my room stat above 18 as it won't get there and will just stay on at full chat all evening.

I don't turn the heating off overnight, but instead turn the thermostat down - we tend to have it set to 17.5C during the day and 15C overnight.

I do have individual "smart" Hive thermostats on the 2 radiators in the living room and set those to 12.5C when we're not using the room (including overnight) and 17.5C when we're going to use the room. If it's really cold then they do sometimes drop to near that overnight, but can't really tell how much the temperature would drop if the heating was actually turned off.

Last night it might have dropped to freezing overnight or perhaps a little below (it was about 1C when I was mountain biking at around 7pm) and I think the living room thermostats were showing something like 13 or 14C when I turned up the hearing at about 7am this morning. That's in a reasonably modern (1997) and reasonably well insulated 5-bedroom detached. The heating will have fired at times during the night though, although probably not to the point where the living room thermostats turned on).

Mike,

Convert to the temperature values to Kelvin. It’s still a drop of 5.5 degrees — from 292.15K to 286.65K — but that doesn’t seem so bad on the Kelvin scale.

Joe

matt j said:

Too many variables I think,

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Of course, Matt, but even with variations , a general idea can be gleaned.

Bob McC said:

Set for 19.
Turned off at 22.00 Last night.
Got up to let dog out at 06.30 Hive registered 15 degrees inside, outside temp was 1 degree when I turned it on.

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Interesting, Bob. you have you htg on 2 hours longer but it's 1.5 degrees higher in the morning. It figures, assuming fairly similar property situations.

SteveG said:

I don't turn the heating off overnight, but instead turn the thermostat down -

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Yes, this would be a good alternative (possibly) but not if you have the bedroom window and door open at night.

eternumviti said:

All of them. I live in a Georgian cottage in a stable block with 9" brick walls and sash windows. There's no insulation at all.

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All of what? Seems you're only one up rom a tent !

There is no degrees Kelvin. It is Kelvin - one Kelvin is the same change as one degree C

Heat loss - varies hugely. I live in a bungalow, the internal hall is usually pretty warm, as is one bedroom with minimal outside wall.
I wear thick shirts and/or jumpers - just second nature, so the lounge never gets seriously warm, two walls are more than 50% glass as well (double-glazed). I suspect that my bedroom drops no more than 2-3-4 degrees even in cold weather, but starts cool - even in hot weather it will not get much over 20-21-22C. My kitchen struggles to ever be warm, even when cooking a roast.

If on the timer, the heating switches off at 9.30.

Joe P said:

Convert to the temperature values to Kelvin. It’s still a drop of 5.5 degrees — from 292.15K to 286.65K — but that doesn’t seem so bad on the Kelvin scale.

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Only just coming to grips with Celsius after all these years (just kidding!). Fahrenheit wouldn't be a drop in the ocean comparably. Besides, your Kelvin loss is identical to Celsius, which it might be as this is beyond my Kelvin/ken)

one lives in a house with central heating which keeps house toasty but of course one turns it off at night
ones neighbour lives in identical house with no central heating at all . both have DG , both same size

the latter is like a fridge and probably a good 5-10 dgrees below ours . i cant quite figure it out really but i guess there is a reason somewhere
cold in day time too !!!

max of 20C in the living room during the day, outside maxed out at 5C When we got up it was 16C inside and 1.5 outside

upstairs in our bedroom it maxed at 24C and min was 21C....too warm for me, but the Mrs likes it warm.

Max temps occur around 2000 in the evening, min around 0600.

Our heating system is very crude, effectively on/off via a timer, and an old thermostat which just keep on max

we do have excellent temperature monitors though from Ubibot

mid terrace, no cavity insulation, but hardly any cavities to insulate. Loft is insulated, but that is old and and could probably be supplemented

A US commentator writes ....

Our thermostat shows 19C @10pm and on a cold night (say -6C in the morning) it will be reading ~13C at 6am before the heating comes on - a loss of 6C in 8 hours - similar to the OP. This is a 1930s build wooden house with retrofit blown in insulation - and old fashioned double windows (~10cm air space).

Heat loss is proportional to the temperature difference, so if we get a really cold night -15C or below the heating comes on during the night - don't want to risk pipes freezing.

4-5 drop doesn't sound bad for a detached.

Urban, solid wall 30s terrace here (which would win no prizes for insulation) and would expect 4C drop down to about 16C overnight on recent cold nights. Thermostat set to 15C overnight and it never fires.

If you have insulated cavity walls, thick curtains may help if drawn at night, as windows will presumably be where you will be losing most heat.

Slice of Georgian house - sash windows, upper floor, only surface exposure is therefore front and rear walls - three rather large windows each. Shutters work; also light curtains. Bedroom window > a meter wide, left open 'an inch or so' but with the internal door shut; hifi sistem and other consumers left unpowered, bar the fridge/freezer and router.

Heat off at 20C at 10pm yesterday in living area; since when it has been -1.5 overnight, no higher that +1C all today.
No heat in the mornings - I get up& out promptly, early, & don't bother. I like a cold start.

Got home today at 6.30pm to 16.0 degC, 20hrs later.

NB: i do have a lovely Antipodean couple as neighbours below, with sim high ceilings: so likely a 5' layer of heated air above their heads/ below my floor ...

Perhaps a better measure - total energy consumption: for my heating, hotwater, shower all from Gas combi / 80sq.m - about 4700KwH in last 12 months.

I have an Eve Degree indoor temp/humidity sensor connected to my Apple HomeKit stuff and last night at midnight my living room temps were 26.4° and 33% humidity, I let my wood/multi fuel fire go out last night at about 2.30am and at midday today my living room temps were at 13.3°, thankfully it wasn’t freezing much last night as the insulation in my housing association 1bed bungalow is utter sh*te.

As my spms progresses I really feel the effects of the cold so for the previous few winters I’ve kept my fire on 24hrs/day to keep heat in the house but I forgot to stock it up and close the door last night, in really cold/icy weather spells I’ve seen my overnight living room temps drop to single figures.

My house is late 1970s four bed detached. In the winter months the heating is on from 07:30 hrs to 22:00 hrs, with the main room thermostat set to 20 C. If it's really cold oiutside, like it is today, I might turn it up to 22 C or more.

At 07:00 hrs the temperature indoors, as recorded by the main room thermostat, will have fallen to around 18/20 C, depending on outside temerature.

I consider the house to be warm, fairly well insulated, and cheap to run. I like it comfortable and refuse to be cold. Total Electricity consumption is around 2,000 kWh/year and gas consumption around 16,000 kWh/year.

End terrace house.

Set temperature in the evening is 18 or 19 degrees.

I usually go to bed around midnight and wake up at 8am.

Temperature on waking is usually 14 or 15 degrees, recently.

So a drop of 4 or 5 degrees over 8 hours.

Seems about average, based on the rest of this thread.