Had a new metric gas meter to replace my old imperial meter - bill calculation

Thomo2710

Hi all,

I had my boiler serviced last week and the gas man noticed that the main gas valve to the house was passing when the supply was turned off.

I reported emergency issue with Nat Grid who sent an enginner out and he replaced it all, and also swapped my old imperial meter over to a metric meter.

Now sad i know - but i keep daily meter readings off both my electric and gas and formulated my own excel spreadsheet to calcualte daily/weekly/monthly use and have found it to be within £1 or £2 of my actual bills.

But now i have a metric meter its thrown my spreadsheet formulas out a little.

Can anybody who is knowledgable enough with both excel and or gas readings/conversiosn and charges please take a look anf check that i am now calculating properly under m3 readings as my calcs show a hell of a lesser usage over the last week compared to the cubic feet usage of previous and our daily human usage has not changed!

eg gone from imperial weekly usage of 40 odd kwh used a week to just half that with the metric readings of about 20 kwh per week!

My spreadsheet can be found here:

http://dl.dropbox.com/u/895609/Gas%20Usage.xls

Many Thanks in advance.

**Note - if other would like to use it - feel free**

macman

A multiplier of 2.83 converts 100's cu ft to cu m.

notbritishgas

Your calculations are correct.
I think the problem is that you are now using per day the same amount of units on the metric meter as on the old imperial one, ie 0.2. That should not be the case.

One metric unit is approx 11kwh and one imperial one is approx 31.5 kwh, so if your usage is the same as befor then I would think you should be using about 0.6 metric units a day.

Thomo2710

notbritishgas wrote: »

Your calculations are correct.
I think the problem is that you are now using per day the same amount of units on the metric meter as on the old imperial one, ie 0.2. That should not be the case.

One metric unit is approx 11kwh and one imperial one is approx 31.5 kwh, so if your usage is the same as befor then I would think you should be using about 0.6 metric units a day.

thanks for the clarification on my calcs

With regards to using 0.6 metric units a day - i have just put dummy figures into the sheet at 0.6 per day and it comes out to approx 43kwh used in a week which as you say is in line with my imperial readings.

now at a loss as to why the readings are so low then!

Going to be fun with my next bill in Dec as i just rang NPower to confirm that they are now metering my account in m3 and they say they have no knowledge of my meter being swapped.

Cardew

Your calculations seem OK - the only difference is that you remove the 'metric conversion factor' of 2.83 now you have a Metric meter. Obviously the calorific value can change slightly but an Imperial gas unit is simply 2.83 times bigger than a metric gas unit.

I would appear that your old Imperial meter was reading too high, or the Metric meter too low. Given the small amounts you are now using I would go for the latter!

The other option would be that the fault you had with the gas valve was leaking gas?

You will get a far better idea in the winter when you are using lots of gas.

Thomo2710

Cardew wrote: »

The other option would be that the fault you had with the gas valve was leaking gas?

well funny you should say that because whenever i opened the cupboard to read the meter there was always a feignt smell of gas in the cupboard and now i dont smell anything!

If it was leaking 20kwh of gas a week though surely it would smell a little stronger than just when i opened the cupboard?

notbritishgas

How are you using your gas at the moment, I guess just for heating water.
To give you some idea:
I have an imperial meter, the water is heated once per day in the morning and takes 1 hour to bring the cylinder up to temperature. We also have a gas hob which is used quite normally but I shouldn't think increases usage by much. I take my readings weekly (not as sad asyou:)) and use about 1.7 to 1.8 imperial units per week.

Thomo2710

notbritishgas wrote: »

How are you using your gas at the moment, I guess just for heating water.
To give you some idea:
I have an imperial meter, the water is heated once per day in the morning and takes 1 hour to bring the cylinder up to temperature. We also have a gas hob which is used quite normally but I shouldn't think increases usage by much. I take my readings weekly (not as sad asyou:)) and use about 1.7 to 1.8 imperial units per week.

Hot water for showers and washing up etc
Also cook on gas hob max twice a week.

Its a combi boiler so its hot water on demand.

AS you can see from my spreadsheet i used to use approx 1.2 imperial units a week.

My girlfriend says i have energy OCD!