Metric and imperial meters Swalec

Mabinogion

Hi
I have an imperial meter for my gas with Swalec (4 numbers)
My brother has a metric meter for the same (5 numbers) on calculating 60 units for mine using the calculation for Imperial meters eg.
60 imperial units used
x 1.02264 volume correction
x 2.83 to convert to metric units
x 39.2 calorific value
÷ 3.6 to convert to kWh= 1890 so that's the figure to x the price of therm which is £2.39 which totals £45.17 just the amount of gas used not adding on standing charge and Vat.

Now my brother is on the same tariff but has a metric meter so they miss out the X 2.83 but using 60 again for comparison using the same calculation without the x2.83 his total comes out at 668 x price of therm £2.39 = £15.95 for same amount of gas used but because his meter measures in cubic meters and mine is measured in cubic feet it is more expensive so this cannot be fair surely?
I phoned up Swalec had lots of discussions as such telling me we are using the same amount of gas but not admitting I was paying more so what do others say about this?

They won't change the meter unless it's faulty or I could get a smart meter and I take issue with the staff who answer the phone trying to pull the wool over my eyes making out that we are using the same amount of gas which yes we would be but I am paying more just using the eg of 60 units but the two different meters throw out a different price so obviously if you have a choice of paying £15.95 or £45.17 which one are you going for?
I only noticed the different calculation on checking my brothers bill !!

Cardew

Why are you using therms? You are charged in kWh

Your error is in stating 'for the same amount of gas used.'

A unit on a Metric meter is approx 11.2 kWh

A unit on an Imperial meter is 2.83 times more i.e. 31.7kWh

Your 60 units on an Imperial meter is correctly 1890kWh but you need to use the price of a kWh(say 3p) = £56.70

Your brothers 60 units on a metric meter are only approx 668kWh. He would need to use approx 170 gas units to have consumed 1890kWh

Robin9

From Wikipedia:

The therm (symbol thm) is a non-SI unit of heat energy equal to 100,000 British thermal units (Btu[1]). It is approximately the energy equivalent of burning 100 cubic feet (2.83 cubic metres) – often referred to as 1 CCF – of natural gas.
Since natural gas meters measure volume and not energy content, a therm factor is used by natural gas companies to convert the volume of gas used to its heat equivalent, and thus calculate the actual energy use. The therm factor is usually expressed in units of therms per CCF. It will vary with the mix of hydrocarbons in the natural gas. Natural gas with a higher than average concentration of ethane, propane or butane will have a higher therm factor. Impurities, such as carbon dioxide or nitrogen, lower the therm factor.
The volume of the gas is calculated as if measured at standard temperature and pressure (STP). The heat content of natural gas is solely dependent on the composition of the gas, and is independent of temperature and pressure.
One therm is equal to about 105.5 megajoules, 25,200 kilocalories or 29.3 kilowatt-hours. One therm can also be provided by about 96.7 cubic feet (2.74 m3) of natural gas. The therm sometimes has been confused with the thermie (see below). The names of both units come from the Greek word for heat.

System

2.39p (not £2.39) per kWh is a very competitive unit price. As Cardew points out: consumers who use more energy pay more for it. That said, it is easy to make a mistake with gas as what is on the meter does not equate to an exact multiplier as calorific values vary.

Mabinogion

Hello
Yes I understand all that but was just pointing out that by using am imperial meter it is more expensive than a metric meter and yes it is a competitive price as it was on offer which was the V11 tariff and that comparing both meters with 60 units using the calculations shown makes quite a difference.

trickytree1963

Mabinogion wrote: »

Hello
Yes I understand all that but was just pointing out that by using am imperial meter it is more expensive than a metric meter and yes it is a competitive price as it was on offer which was the V11 tariff and that comparing both meters with 60 units using the calculations shown makes quite a difference.

You are consuming more gas with 60 units on an imperial meter than 60 units on a metric meter

System

Mabinogion wrote: »

Hello
Yes I understand all that but was just pointing out that by using am imperial meter it is more expensive than a metric meter and yes it is a competitive price as it was on offer which was the V11 tariff and that comparing both meters with 60 units using the calculations shown makes quite a difference.

A meter is a meter; it just measures the volume of gas that passes through it. Gas measured by an imperial meter is no more expensive than gas measured by a metric meter as 60 units on an imperial meter is not the same volume as 60 units on an metric meter.

What matters here is the conversion of metered units into kWhs - not Therms. This is why the two equations to convert volume into kWhs are different. We are all billed for the kWhs that we use.

I suggest that when you are next with your brother, you look again at the two bills and the conversion to kWhs that has been used for billing purposes.

Cardew

Mabinogion wrote: »

Hello
Yes I understand all that but was just pointing out that by using am imperial meter it is more expensive than a metric meter and yes it is a competitive price as it was on offer which was the V11 tariff and that comparing both meters with 60 units using the calculations shown makes quite a difference.

An analogy.

Take a 'Imperial' pump dispensing petrol in gallons. If you fill your petrol tank with 10 units on the meter; you have taken 10 gallons.

If you take 10 units from a 'Metric' pump dispensing petrol in litres, you have taken 10 litres or approx 2.2 gallons.

That is in effect what you are doing with your gas meter comparisons. However you are making the mistake in thinking that 60 gas units on either meter is the same amount of gas; and it ain't! The gas unit on your Imperial meter 'dispenses 2.83 times more than a gas unit on your brother's metric meter.

Mabinogion

Hengus wrote: »

I suggest that when you are next with your brother, you look again at the two bills and the conversion to kWhs that has been used for billing purposes.

The calculation used on the metric meter is
X 1.02264=
X 39.2=
/ 3.6 =
X 2.39p (unit price)

On the Imperial meter you use the same calculation only you add the X 2.83 after the first sum X1.02264

molerat

Everyone on this thread is aware of that, it seems that you still have not figured out the significance of that 2.83.

Gas is billed in kWh.
An imperial meter unit is 100 cu ft. A metric meter unit is 1 cu m. 100 cu ft is 2.83 times the volume of 1 cu m. You get 2.83 times the kWh from an imperial meter unit that you do from a metric meter unit so you pay 2.83 times the price of a metric meter unit for an imperial meter unit.
You both pay exactly the same price for a kWh.

Mabinogion

molerat wrote: »

You both pay exactly the same price for a kWh.

So if we are charged the same price why is mine more as on my one bill
16.00 imperial units used x 1.022640 volume correctionx 2.83 to convert to metric= 46.30 metric units x 39.2 calorific value ÷ 3.6 to convert to kWh = 504.15 kWh
So 504.14 x 2.39p = £12.05

My brothers bill for 17 units comes out at
17.00 metric units used x 1.022640 volume correction = 17.38 corrected units x 39.2 calorific value ÷ 3.6 to convert to kWh = 189.24 kWh
So 189.14 x 2.39p = £4.52

So this is my query he pays £4.52 I pay £12.25
Sorry just can't get my head around this at all sorry
I understand the gallons/litres explanation but the cost of my bill is more even using a bit less 😵