Calculating garage heater cost to run

[bochnak]

I trenched a poly gas line from meter to garage this year...about 100-125'.

I installed a 75k BTU (input) natural gas heater in the garage and only run it when in the garage.

A therm goes for roughly $0.50 around here. A therm is 100k BTU/h.

So here go the calcs:

75k BTU/h (heater input) / 100k BTU/h (therm) = .75 therm per hour of continuous running. Per hour cost is .75therm X $0.50 = $0.38.

I'm questioning my calcs since my last gas bill was quite higher than I had expected, and suspecting a leak. I checked all joints with soapy water and appear to be leak free. I guess I should have the poly line pressure tested?

Also, I don't know what size my meter is, but have heard that if you are pulling more volume than rated, you will pay more than actual gas use?

 

[tomroblee]

Matt,

Your math is correct.

I don't know the "standard" size of a residential gas meter in the Chicago area, but in Indianapolis the most common meter is a 250 which means that the meter can pass 250 ccf (hundred cubic feet) of gas per hour without an undue pressure drop. This is roughly equivalent to 250 therms per hour. The meters will usually run up to 150% of the rated capacity without creating any problems. The accuracy of a residential (positive displacement) meters will vary somewhat depending on the load, but not enough that you would notice.

Your current cost per therm may be about $.50, but the prices have varied widely over the past couple of years. In comparing consumption you need to make sure that you are comparing therms rather than $$$. You might want to look closely at the your last two or three bills and compare the last meter reading to what your meter now registers. It is possible that that your high current bill is because there was an estimated reading (rather than an actual reading) or that the meter reader misread you meter.

If you can't find an explanation by reviewing your bills, testing your new gas line is a wise idea. You may have to hire a plumber or heating contractor to do this. Your local gas utility would probably test the lines on your side of the meter for free (or a minimal charge)----but only to see if there is a leak somewhere on your side of the meter. If they find that the lines on your side of the meter are leaking (or that there is some other unsafe condition) they will turn off you gas until you can show them that the leak or other unsafe condition has been fixed.

 

[bochnak]

My meter readings are taken every other month. Months in between are estimated. Nov bill was estimated, Dec is actual

Around this time of year, I use about 50-100 therms. Lets just say I use 75 therms. My bill showed that I used 250! I have never used this much even in the coldest months.

I had the poly line attached to the meter 11/5, and shutoff right outside the garage. So if there is a leak from meter to garage, it had the chance to leak from 11/5 to 12/22 when actual reading was taken.

I did not have the heater hung, vented, etc...until 11/26. I would say that I have spent about 20-30 hrs in the garage from 11/26 thru 12/22, so I estimated that I should have used an additional 20 therms worse case.

I think my bill should have been around 90-100 therms. I don't know where 250 therms went?

 

[bochnak]

This meter supplies my 60k home furnace, 75k garage furnace, 40k? water heater, dryer, and stove.

I'll try to get a model # from the meter.

Only change this year is garage heater. Yes, garage heater has a pilot light. Pilot only runs when I am out in the garage. Gas is shutoff otherwise.

 

[bochnak]

I will clock the meter hopefully tonight:

http://www.bacharach-training.com/referpage/clocking_gas_meter.htm

 

[tomroblee]

The link in your last post didn't work, so I'm not really sure what you mean by "clocking the meter".

Your "extra" consumption of about 150 therms over a nearly two month period of time equates to about ten cubic foot of gas per hour. If all of your gas appliances are off, the meter shouldn't turn--unless there is a leak or at least one of the appliances has a standing pilot light. A pilot light should use about 1/2 of a cubic foot per hour. You should be able to turn off all your gas appliances and see if the gas meter is still turning more than any pilot lights would use.

I hope that you used poly "gas" pipe (rather than water pipe or ???) and installed it correctly. Anything above ground has to be metal pipe, so the transition between the metal and poly pipe will be buried. A special (and expensive) compression fitting is required for the transition. The most likely place for a leak is at the transition fittings at either end of the poly pipes--unless the poly pipe itself has been damaged. If the pipe is buried in rocky ground, it should be cushioned by a layer of sand. Burrowing animals have been known to gnaw on the pipe in very rare instances.

You should still compare the reading on your last bill with what your meter currently shows. Meter reading and billing errors are occasionally made by all utility companies.

You seem to be on the right track

 

[bochnak]

I will clock the meter hopefully tonight:

http://www.bacharach-training.com/referpage/clocking_gas_meter.htm

The link in your last post didn't work, so I'm not really sure what you mean by "clocking the meter".

Try the link again. I clocked the garage heater to see if it was over or under firing.

 

[bochnak]

Alright, I shut off every gas valve in the house and garage right at the furnace/appliance. The line to garage right up to the furnace had gas applied (not shut off to determine if leaking). I did not see the meter dial spin at all in the 1-2 minutes I was watching. Maybe I should try this over the weekend for an hour? With the water heater pilot on, I can see it move very slow, obviously.

I ran only the garage heater and clocked it right at 75k BTU. I timed 24sec on the 1/2 cu ft. So that is right on the money. For the heck of it, I ran the garage heater (75k), home furnace (60k), and dryer (don't know the BTU rating) and timed 9sec, or 200k BTU. So the dryer is sbout another 65k BTU?

The meter reading on the bill is correct. Darn.

The meter is a Sprague 175. Any concerns with this meter?

I did use the yellow gas poly line and special expensive compression fittings (fittings were like $30 ea). The ground was not rocky at all, however near a mature tree.

 

[bazzateer]

Maybe other members of the household have been running gas appliances to excess?

 

[HoosierBuddy]

Well...

In my experience a "high bill" complaint without any other symptoms (i.e. smell gas leak) is never a leak. I'm not saying it can't happen...I'm just saying I've never seen it. If you watched the 1/2 foot hand on your meter for 2 minutes and it didn't move, any leak you have would have to be very small. I know a lot of gas companies procedures for a lock up test are to watch the hand for 5 to 10 minutes...but honestly...you'd see a decent leak within 2.

IIWY...I'd start reading my meter daily and see what you can figure from that. You can look at your usage when you are using your garage and when you aren't and draw some conclusions.

Also...I don't think 50 cents a therm is high enough. Check your bill, but I think your gas is likely closer to $1.00 a therm riht now.

Phil

 

[bochnak]

Maybe other members of the household have been running gas appliances to excess?

Well we hosted thanksgiving, are taking longer hot showers, etc.....but nothing that we haven't done in recent years.

 

[bochnak]

I have started writing down the date and amount of time I run the garage heater to justify increases.

Therms in my area for Dec are $0.50. I just paid $163 for 254 therms, so acually $0.64 after all taxes and delivery charges have been factored in.

 

[tomroblee]

The tag on the Sprague meter that says 175 means that the manufacturer of the meter (ownership of the Sprague name has changed several times in the past 25 years) has labeled the meter as 175 cubic feet per hour. However most folks that deal with gas meters treat it as equivalent with other brands that are labeled for 250 cubic feet per hour. A cubic foot of natural gas has approximately 1,000 btu. When every gas burner or your property is burning at maximum capacity (all burners on your stove on high and the oven on), you might tax the limits of the meter. Your water heater is probably 30,000 to 40,000 btu. Most gas clothes dryers are about 20,000 btu. Each burner on your stove could range from about 5,000 to 16,000 btu on high settings.

Gas meters are generally fairlly accurate. When a meter become inaccurate, it is nearly always still generally at least 95% accurate--or it quits registering at all. In most instances where there is concern over high readings, the cause is an improper reading. Have you reviewed you past bills for the past year to see if it looked like your consumption was 100 or 200 therms lower than normal in some month? If you don't keep you old bills, your gas utility should be able to look up your usage on their computer.

As I recall, the Sprague 175 RM meter was introduced in the early 1970's and was discontinued in the mid 1990's. Some utilities have their older meters rebuilt and others have found it cheaper to just buy new meters. If the dials on your meter turn in a jerky fashion and/or the meter is very noisy, it may be an indication that the meter is due for replacement.

Probably the most common cause of unexplained increased use is when there is a hot water leak or dripping hot water faucet somewhere. If you have a major gas leak in your house you will likely smell it.

I think that you are attempting to do the right things. Good luck!!

 

[bochnak]

For the heck of it, I ran the garage heater (75k), home furnace (60k), and dryer (don't know the BTU rating) and timed 9sec, or 200k BTU. So the dryer is about another 65k BTU?

Most gas clothes dryers are about 20,000 btu.

According to my clocking with these 3 running, my dryer is using 65k, seems like a lot to me.

My water heater is a 40k.

In my case, the water heater, home furnace, and garage heater can run all at once.

 

[bochnak]

Have you reviewed you past bills for the past year to see if it looked like your consumption was 100 or 200 therms lower than normal in some month? If you don't keep you old bills, your gas utility should be able to look up your usage on their computer.

As I recall, the Sprague 175 RM meter was introduced in the early 1970's and was discontinued in the mid 1990's. Some utilities have their older meters rebuilt and others have found it cheaper to just buy new meters. If the dials on your meter turn in a jerky fashion and/or the meter is very noisy, it may be an indication that the meter is due for replacement.

I have a usage bar graph on every bill that spans 12 months. Usage has never been this high in the 3 years I have lived here. The only change is the garage heater which I know should have only added 20-30 therms worse case.

The dial may seem a bit jerky to me. The rotation of the needle varies fast/slow, but I think that may be normal since the numbers are not equally spaced.

 

[HoosierBuddy]

It's not the gas meter. They don't fail "fast". They can just flat out quit.

The most common mistake when reading a gas meter is to miss it by 100 therms. Is it possible the reading is off 100?

If any dial is between 2 numbers, you have to read it as the LOWER of the 2 numbers. If the preceeding dial has not reached zero...then the dial should STILL be read as the lower number.

For example:

Your dials are as follows:

Left points between 5 and 6
Next one to the right is pointing at 8
Next one points between 9 and 0
Next one is between 2 and 3

That meter reads 5792

If someone is in a hurry...it's awfully easy to read it as 5892...but it isn't because the 1000 hand isn't to 0 yet....which means the 8 is really a 7.

As far as "#1 thing that causes gas bills to be higher than expected" here's a good link:

http://www.indiananatural.com/energysavingtext.html

Note that "heating an unoccupied building or garage" is number 1 on the list.

Phil

 

[nate379]

I use around 160-170 therms a month to heat the house/garage in the winter. Would be nice if it was $0.50/therm. It's over $1/therm here.

Summer usage is right around 40 therms/month.

 

[bochnak]

It's not the gas meter. They don't fail "fast". They can just flat out quit.

The most common mistake when reading a gas meter is to miss it by 100 therms. Is it possible the reading is off 100?

If any dial is between 2 numbers, you have to read it as the LOWER of the 2 numbers. If the preceeding dial has not reached zero...then the dial should STILL be read as the lower number.

For example:

Your dials are as follows:

Left points between 5 and 6
Next one to the right is pointing at 8
Next one points between 9 and 0
Next one is between 2 and 3

That meter reads 5792

If someone is in a hurry...it's awfully easy to read it as 5892...but it isn't because the 1000 hand isn't to 0 yet....which means the 8 is really a 7.

As far as "#1 thing that causes gas bills to be higher than expected" here's a good link:

http://www.indiananatural.com/energysavingtext.html

Note that "heating an unoccupied building or garage" is number 1 on the list.

Phil

Meter reading matches bill. This is one of the things I have checked hoping for an error.

 

[bochnak]

I use around 160-170 therms a month to heat the house/garage in the winter. Would be nice if it was $0.50/therm. It's over $1/therm here.

Summer usage is right around 40 therms/month.

I typically use 170 for the coldest months (no garage heat). In the summer, I use around 40 as well.

Home is a 1000 sq ft brick ranch with full basement which I do not heat (vents are closed). Furnace is a 92.1% 60k.

 

[tdkkart]

Meter reading matches bill. This is one of the things I have checked hoping for an error.

Yes, but did it match last month??

You gotta watch those meter readers, we have different readers every month. My place is funny to watch them, they read the house gas and electric then leave, only to come back to read the shop meter.

I went through hell last year after we moved in, their first read the day we moved in was wrong. Then they started estimating, only problem was we put in a gas furnace, along with a meter that had never been there before. They estimated the gas meter at 0 for the first three months. When I finally forced them to come out and read my meters they read them wrong.

I raised hell with one of the local TV stations, they did an "investigation" and found that they were estimating almost everyone's meters way too high. We've had actual readings every month since.

Shut down all your gas burning appliancs for an hour or 2 and watch the meter. If it moves you've got a leak, if not your burning it, like it or not.

 

[TheGrooveking]

My brother moved into his newly built house in Lindenhurst Illinois back in 2000, he shortly after had a gas burning log put into his fireplace. For the first three winters he ran that thing all of the time. I distinctly recall asking him aren't your gas bills through the roof? He said no, his gas bills are right around $80 a month, I was shocked, how my gas bills for my home are running $180 and I'm not running either of my fireplaces.

Well long story short, his neighbor and him were talking one day and the neighbor said well my gas bills are killing me, they are around $400 to $500 a month during the winter. So the neighbor contacts Northern Illinois Gas and they look into and at first couldn't find anything wrong. The neighbor complains again and this time whoever looked into checked the serial number on his meter and noticed it wasn't correct to what was listed on his account. Then the gas company searched deeper and found out that my brother's gas meter serial number was actually the one on his neighbors account. So they credited the neighbor a boat load of money and then sent my brother a bill for over $6K.

My brother contacted his lawyer and by law they were only able to go back 12 months, so my brother had to pay $2,300 to the gas company. Needless to say that fireplace only gets turned on a few times a year now.

TheGrooveking

 

[bochnak]

I clocked most of the units individually and found the following (parentheses indicated input shown on the "label" of unit):

1. Garage heater (75k) clocked @ 75k.
2. Furnace (60k) clocked @ 50k.
3. Dryer (22.5k) clocked @ 20k.
4. Water heater (40k) clocked @ 30k.

I ran units 1,2, & 3 together. Adding total clocked #'s above should 145k. Well, actual clocked value was 171k, 26k difference.

I also ran units 1,2,3, & 4. Adding total clocked #'s above should be 175k. Actual clocked value was 200k, 25k difference.

When individual units are operating, the dial rotates smoothly.

When I ran multiple units, the 145k & 200k load, the dial was jerky and had inconsistent rotating speed. It made "clicking" sounds as the speed on the dial changed.

Time to call the utility company or what?

 

[crankshaftdan II]

We don't have "Meter Readers" here in S.W. Wisconsin anymore, we advanced to the much more highly approved satellite reading meters! I have had three (3) changed out in the four years since they made the change! Seems that the little gears in the units strip-out real easy as they are made now in "Mexico". My bills were on the high side as they were averaging them over a 12 month period and I did complain (finally got some $$$ back) Power company indicated that this was a cost savings! To whom????? Seems like a pain in the a-- as they got rid of meter readers and bought the el-cheeepo made in Mexico meters. Sort of sounds similuar to cheep tools breaking thread!! My two cents worth!!

 

[HoosierBuddy]

I clocked most of the units individually and found the following (parentheses indicated input shown on the "label" of unit):

1. Garage heater (75k) clocked @ 75k.
2. Furnace (60k) clocked @ 50k.
3. Dryer (22.5k) clocked @ 20k.
4. Water heater (40k) clocked @ 30k.

I ran units 1,2, & 3 together. Adding total clocked #'s above should 145k. Well, actual clocked value was 171k, 26k difference.

I also ran units 1,2,3, & 4. Adding total clocked #'s above should be 175k. Actual clocked value was 200k, 25k difference.

When individual units are operating, the dial rotates smoothly.

When I ran multiple units, the 145k & 200k load, the dial was jerky and had inconsistent rotating speed. It made "clicking" sounds as the speed on the dial changed.

Time to call the utility company or what?

For your piece of mind (since you are convinced this is a meter problem) you should call them and ask for details on a meter test. In some states, they are required to test you meter ONCE for free, if you ask. I don't know if that's true in Illinois, or not, but it wouldn't surprise me.

What they will probably do is change out your meter with a new one and send your old one in to be tested at a meter shop on a meter prover. It might take a couple of weeks to find out the results. I've got $20 that says it checks within 3% +/- if you'd care to wager.

Phil

 

[tomroblee]

A jerky, noisy gas meter usually indicates that something in the meter is about worn out.

I've never seen a situation like you describe before. A summer usage of 40 therms per month is at the high end of gas usage for someone who is likely only using a gas water heater, stove, and dryer at that time of year. I don't have a gas dryer, but use about 15 to 20 therms a month in the summer. This is with two adults in the household taking a shower each day, a couple of loads of laundry a week, and not a great deal of cooking. If you have a few more people in your household, a summer usage of 40 therms would be normal.

You say that your normal usage is 50 to 75 therms in December. This seems rather low even with a fairly small house and an efficient furnace. Winter usage generally increases 10% to 30% even for people without gas heat. I suspect that this is because they spend more time at home in the winter, may take longer showers, and their water heater works harder because the incoming water is several degrees cooler in the winter.

Your utility company (Nicor??) should test your meter for free if it has not been otherwise tested in the past 12 months. In practice, they will install a new meter on your house and take the old meter back to their shop (or outsources shop) for testing. When you call to request a test, tell them the btu ratings of you connected load. I imagine that they will upgrade your meter to a 240 or 250 (the next larger common sizes).

The various meter "clockings" that you have done with various appliances running seems a bit on the strange side, but does not suggest any reasons why you could have used an extra 150 therms in a month.

 

[bochnak]

Here is an update:

1. There was a little leak at the meter that was fixed by the utility company. It was so small that I could not see the dial move on the meter after watching it for a few minutes.

2. Meter reading was incorrect. On 12/22, it was 9392. It was read again on 1/4/10, 9371. However, therm usage per day went from 7 to 5, normally it’s around 2 this time of year.

3. Meter was replaced no Q’s asked. I re-clocked everything and is way more accurate. It’s right within the input ratings that I previously posted. Dial is still jerky, so I think that is normal. Meter does not make anymore noises.

4. Co-workers, friends, and family also had high gas bills, even though average temp is higher this year than last.

 

[Possum]

Did they up the delivery charge on the gas?

 

[bochnak]

Did they up the delivery charge on the gas?

I'm comparing therms only.

 

[Possum]

That was in reference to your friends and coworkers bills being higher also. Did they use more gas or was their bills just higher? Great thread BTW. I will be clocking my meter when the snow melts a bit.

 

[bochnak]

That was in reference to your friends and coworkers bills being higher also. Did they use more gas or was their bills just higher? Great thread BTW. I will be clocking my meter when the snow melts a bit.

Yes, the bill(s) show a bar graph of therms used for the past 12-13 months. All are way high for this time of year and we are all stumped since avg temp was higher for estimated and actual reading months (Nov & Dec).