Daily gas consumption

Gerry1

FreeBear said:

Jibber123 said:

I've been doing some experiments with the heating and I read the gas meter yesterday lunchtime, left the heating on for 9 hours then turned it off, read the meter this morning and we've used 112kWh of gas. I only had the TRV's open in several rooms we use during the day, kitchen, bathroom, hall, landing, and 2 bedrooms and they were set at 17C. This usage seems very high considering its not very cold yet. What do people use in a typical day during the winter. I know its dependent on the size of the house, insulation, boiler, etc.. but i'm looking for comparisons and what to aim for. 

112KWh of gas over 9 hours works out as 12.44KW per hour

Sorry, but it doesn't !

112kWh of gas over 9 hours works out as 12.44kWh per hour; OR

112kWh of gas over 9 hours works out as 12.44kW per hour.

ArbitraryRandom

If we're gong to be pedantic about it, it's not 12.44 of anything per hour in reality The boiler will be working harder at the start then modulate to maintain (if it's working correctly!) 

The question is if it's working that hard because the house is a heat sink/poorly insulated, or if the heat isn't getting into the space efficiently, or the thermostat isn't working properly, or if there's another problem. 

OP - I know this is a very basic question... but how did you calculate the usage (i.e. are we sure this isn't a mistake converting from either metric or imperial to kWh)?

Jibber123

MeteredOut said:

Which model of WB Greenstar? There at different kW rated versions (eg, 29 to 42).

And, that usage seems high, unless, as suggested above, you were heating your house from a low based and it your boiler was not condensing. What gas meter model to you have?

Its a 42kW boiler but that was put in as its a chalet bungalow with 3 extra bedrooms in the loft that we rarely use, plus a large dining room which is only used if we're entertaining. hence the rads in those rooms are left on the frost setting. I also checked them several times yesturday to make sure they hadn't come on. 

Jibber123

the meter reading were 

8925.72

8929.26

cu ft
 which is 3.54 cu ft converted to kWh is (3.54 x 2.83) x 38 x 1.05584 ÷ kWh Conversion Factor (3.6) = 111.97 kWh

112kWh in 9 hrs = 12.5kW per hour as its a 42kW boiler its obviously running a lot lower than max which id expect with half the rad's off and a reasonably mild day.

Its a 1950's detached 2 bed bungalow, uninsulated cavity walls, with single glazed leaded light crittle windows, but these have secondary double glazing installed in all the rooms we use regularly and heat. The kitchen is a more modern 1999 extension insulated cavity walls and timber double glazing. The house tends to go cold quickly after we switch the heating off, in about an hour is back to normal temperatures, like it is first thing in the orning before the heating is put on. 

northernsoul

Well , most of you seem to be in a non leaky house !
i live in a 130 year old terrace house , 2 bedrooms and a attic bedroom. No insulation apart from 2 inch (50mm) kingspan on attic ceiling. 14 foot (4.27m) wide * 28 foot (8.54m) deep house. 9 foot 6 inch (2.8m) high ceilings.
In February 2021 in Yorkshire it was down to -2C. With needy lodgers wanting the thermostat set to 21C , my 12 year old Vaillant ecotec plus 837 (28kw) boiler used 2813kw over 28 days or 100 a day !

Spies

Currently using 30-40kWh a day depending on if its a weekday or weekend and outside temp.

Not a particularly well insulated house

I have it set to 18c between 8am and 10am, then 19c between 5pm and 9pm.

QrizB

Jibber123 said:

... I read the gas meter yesterday lunchtime, left the heating on for 9 hours then turned it off, read the meter this morning and we've used 112kWh of gas.

That seems quite a lot, although from the sound of it you have a larger house than my 1950s three bed semi.

Jibber123 said:

What do people use in a typical day during the winter. I know its dependent on the size of the house, insulation, boiler, etc.. but i'm looking for comparisons and what to aim for. 

My worst monthly gas use in the past five years was just over 2000kWh. Call it 70kWh a day, on average, for that month.

Alnat1

4 bed detached built 2003 so fairly decent insulation. Heating on 6.30am to 10pm each day, average gas use over the last week is 23.6kWh a day. Thermo set at 18C.

That includes around 4kWh to heat the hot water tank daily and a bit of hob cooking. Average daily temps varied between 9.9C (14.83kWh) with plenty of solar gain and 7.1C (33.81kWh) rain all day.

markin

Jibber123 said:

MeteredOut said:

Which model of WB Greenstar? There at different kW rated versions (eg, 29 to 42).

And, that usage seems high, unless, as suggested above, you were heating your house from a low based and it your boiler was not condensing. What gas meter model to you have?

Its a 42kW boiler but that was put in as its a chalet bungalow with 3 extra bedrooms in the loft that we rarely use, plus a large dining room which is only used if we're entertaining. hence the rads in those rooms are left on the frost setting. I also checked them several times yesturday to make sure they hadn't come on. 

Which means the heat loss from the rooms you heat to the rooms you don't is large, you basically are heating the entire home with limited number of rads with 40c water, was it it also a cold start with the fabric being cold?

We would expect day 2 to reduce use but I can take a 3-4 days to get to the lowest usage

tim_p

Jibber123 said:

Yes its a condensing boiler Worcester Bosch Greenstar CDi Classic, aprox 5 years old. I've put temperature gauges on the flow and return and after about 30 mins they are 36.6C and 40.1C.

Unless those temp gauges are known accurate AND they have a good thermal connection to the pipes, I wouldn’t necessarily trust those readings.