Gas usage sensible?

[David]

Hi there,

I was just wondering if we are using an excessive/normal amount of gas.

The boiler we have is a Vaillant ecoTEC+ 937 combi boiler.

DHW: 37kw...tank in boiler set at 50C..automatic disinfection if needed. CH: 12kw-28kw..the boiler is range rated at 14kw

Two zones, one controlled by a Honeywell CM927 and the other by a Salus RT500 or similar.

The house is a 4 bed semi detached house, with 5 people living in it, occasionally my sister and her husband will come to visit.

Our gas meter is a metric type.

January: 393 units February: 317 units March: 260 units. April: 166 units (heating used for nearly half the month) May: 111 units (heating used for around three days or so) June: 65 units.

Is this usage classed as excessive?

[David]

Forgot to say that heating was in operation Jan-March also.

[martin_pentreath]

When you say metric, what are the units, do you mean it measures in cubic metres? If so that is astronomical, so I assume the units are something else, unless your house has no roof and you like to keep it at a comfortable 35 deg C at all times. Being embarrassingly obsessive about this, I keep our readings in a spreadsheet. This is for a three- bedroom victorian terrace with fairly poor insulation and a 27kw non- condensing combi boiler. The first column is the meter reading. The second one is the rate of usage in units per day calculated by the spreadsheet. The units are cubic feet, so you'd have to multiply by something-or-other to compare with your metric readings (whatever units they're in). I'd say we're on the stingey side with heating (as is consistent with someone who records meter readings in a spreadsheet).

Cheers!

Martin

02/07/2007 9718 0.96 22/08/2007 9755 0.73 30/08/2007 9761 0.75 16/09/2007 9772 0.65 05/10/2007 9798 1.37 15/10/2007 9812 1.40 22/10/2007 9827 2.14 26/10/2007 9841 3.50 02/11/2007 9860 2.71 14/11/2007 9897 3.08 21/11/2007 9928 4.43 05/12/2007 9971 3.07 15/12/2007 11 4.00 06/01/2008 75 2.91 18/01/2008 102 2.25 26/01/2008 118 2.00 01/02/2008 132 2.33 20/02/2008 190 3.05 03/03/2008 212 1.83 29/03/2008 277 2.50 07/04/2008 290 1.44 23/04/2008 324 2.13 22/07/2008 350 0.29 06/08/2008 352 0.13 15/08/2008 353 0.11 21/09/2008 360 0.19 08/10/2008 371 0.65 28/10/2008 393 1.10 15/11/2008 427 1.89 18/12/2008 507 2.42 30/01/2009 637 3.02 12/03/2009 758 2.95 08/04/2009 796 1.41 02/06/2009 821 0.45 09/07/2009 825 0.11

[robert]

Similar usage to above 3 Bed 3 floor Georgian terrace - stone rubble walls -no DG. Winter use 2.0 to 2.7 Units = 60-80 kwh approx. Summer use 0.15- 0.25 units = 4.5 - 7.5 kwh

Total annual use 15,500 kwh for heating, hot- water and hob on gas cooker.

I think OP has a decimal point wrong ( 10 x too much)

[David]

The meter is like this:

record the numbers in black.

Example: Beginning of January the black numbers read 6695, at the end of the month the numbers read 7088..393 units used?

[John Rumm]

IIRC "Units" are traditionally 100 Cu Feet in size, which would make the reading about 138 units.

[Roger Mills]

Yes, but the 'Unit Price' quoted by energy suppliers is always in kWh - so the OP really needs to convert the meter readings into kWH (taking account of the various 'fiddle factors' and calorific value, etc. - as shown on the gas bill). Only then can we be sure that we're not comparing apples with pears!

[David]

I posted something similar on another forum.

This was one of the replies: "Are you sure it is a metric meter and

393 are the black figures, not the red?

If it is 393M=B3, that's about 12,500kWh in one month. My boiler only uses 26,000kWh in a year and in the last two months it has used 226M=B3, which is about 30% of what you have used.

You seem to have a large house - three floors. Is it an old house with poor insulation etc?"

I am really confused.

[John Rumm]

Can you give us the small print sums off your Bill? There should be a place where they convert from measured "units of some description" to kWh.

[Andy Cap]

Your meter clearly measures in cubic meters. If you roughly double your figure to give an annual total it works out at... 2624 m3

To convert that to KW, x by Calorific value x corr factor / 3.6

= approx 29000KW

I would guess that's about double the average consumption with an efficient boiler, but of course it depends how well your house is insulated and how you live. Family not whacking up the thermostat all the time. Water on all the time for constant baths and showers. Windows and doors left open. Andy C

[David]

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D\

=A0 =A0 =A0 =A0|

=A0 =A0 =A0 =A0|

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D/

Good evening John,

Calorific value: 39.212......this was the bill for May.

kWh used: 1236

How we calculate kwh on your gas bill

We use the industry standard formula for this calculation. We take the difference between the present and previous readings, and multiply it by 2.83 to convert it from cubic feet to cubic meters. (This step is not needed if you have a metric meter) Then we multiply the cubic meters by the volume conversion factor (1.02264) and then by the calorific value. Finally we divide the answer by 3.6 to give the number of kilowatt-hours.

How's that?

[David]

This is what worries me, one zone is kept at 19.5C whilst the other is kept at just 16.5C, and the heating is not on constantly and the women generally feel cold!

[geoff]

Pretty as your picture is - binaries are not allowed in uk.d-i-y

[Andy Cap]

Ah, but what are they set up when you're not there ? ;-) Have you plenty of loft and cavity wall insulation ? They make a lot of difference. I think it's really difficult to compare different properties, because numbers and habits vary so much. The best thing is to maximise the saving in your own property, with insulation, controls like TRVs, an efficient boiler, although that will take years to pay for itself and a big stick, as and when required.

[David]

ote:

They can't be setting the thermostat above 21C due to Honeywell flexibility, my sister usually turns it up to 20C or so but now that she is gone it shouldn't be much of a problem. And the zone at 16.5C is my room which is in the loft. The loft is cold as the insulation was put between the joists rather than the rafters, the hatch is permanently open because I am going in and out of my room all day. Unfourtunately the walls are solid so no insulation, however the extension to the kitchen and living room have cavity wall insulation.

Double glazing is present throughout the house.

=A0I think it's

There are TRV's on all rads and the boiler is a condensing boiler, it is 91.5% efficient I believe.

[robert]

If you used 1200 kwh this is roughly 40m^3 I suggest you are a factor of 10 out in your meter readings.

If May was coldish your consumption is probably within the normal range.

[David]

Can you tell me the proper way of the meter then?

I am very confused..some telling me my usage is high..some telling me it is normal...................

[robert]

If you used 1200 kwh this is roughly 40 ft^3 I suggest you are a factor of 10 out in your meter readings.

If May was coldish your consumption is probably within the normal range. (Mine is 15500kwh per annum)

[Andy Cap]

Well, there is no way I would contemplate leaving the loft hatch open. That must represent a pretty substantial loss. I don't know for sure, but I would have thought solid walls were a bit of a liability heatwise too. Like the other guy, I use just under 14000KWs in a 3 bed semi and that's with an ancient boiler, but there is only two of us, so not so much water for sure.

[John Rumm]

Robert,

This post appears twice, and in two variants; one saying 40 ft^3 and the other 40 m^3