# How much water in a copper tube?

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• posted on April 15, 2014, 9:22 am
On Thursday, March 17, 2005 10:29:15 AM UTC-7, snipped-for-privacy@spamcop.net wrote:

Dimensions and Physical Characteristics of Copper Tube: TYPE ACR 3/4 OUTER IS .750 INNER IS .666 CONTENT GAL .242 PER FT
Dimensions and Physical Characteristics of Copper Tube: TYPE M 3/4 OUTER IS .875 INNER IS .811 CONTENT GAL FT .269 PER FT
Dimensions and Physical Characteristics of Copper Tube: TYPE L 3/4 OUTER IS .875 INNER IS .785 CONTENT GAL FT .251 PER FT
http://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf
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• posted on March 18, 2005, 7:12 pm
bill a wrote:

What was the ID?
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FF

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<%-name%>
• posted on March 18, 2005, 7:12 pm
bill a wrote:

What is the ID?
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FF

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• posted on March 22, 2005, 5:18 am
I am putting a tankless gas water heater in my home. All of the copper is in the concrete slab so I am going to run an insulated copper tube "up and over" to the kitchen. The water heater will be a foot from the two bathrooms and showers. the "up and over" tube will feed the kitchen sink and dish water - nothing else.
How much water is in a 100 foot by 1/2 inch copper tube? How much water is in a 100 foot by 3/4 inch copper tube? How much water is in a 100 foot by 1/4 inch copper tube?
I am too lazy to look it up - I am wondering if any of you experts on here have the info off-hand. I am thinking of putting thinning tubing to the kitchen because less water would be in it to cool down etc.
Right now I am running two 50 gallon electric water heaters in a house for two adults - I am wasting alot of energy keeping all that water hot - and the tanks are far away from where the hot water is needed anyway running thru a cold concrete slab.
Harry
This is ReRe
1/2" = .0158 gallons per lineal foot or 1.58 gallons in 100' 3/4" = .0277 gallons per lineal foot or 2.77 gallons in 100'
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• posted on March 15, 2005, 10:32 pm
Refigeration tubing is ID, Plumbing pipe is sized by OD.
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Bob Pietrangelo
snipped-for-privacy@comcast.net
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• posted on March 15, 2005, 11:52 pm
Bob Pietrangelo wrote:

Bob, Check your references. You have it backwards. Refrigeration tubing (ACR) is sized by the actual OD. Plumbing & heating tubing is sized by the nominal I.D. Therefore 1/2" plumbing tubing has an actual OD of 5/8". I just checked my textbooks to verify this so as not to give dis-information.
Source: Refrigeration & Air Conditioning Technology, 3rd Edition, 1995, page 99.
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• posted on March 16, 2005, 12:28 am
wrote:

Hi - No need to argue. I just wanted to find out how much water was in a 1/2 inch by 100 foot copper tubing. Just a ball park amount. I was surprised at just how little an amount of water it is. I am not worrying about wasting water - I am trying to cut down the time it takes for hot water to get to my showers. I am surprised it hold less than a gallon of water. If I insulated that 100 feet of copper tubing - the water in it will not cool off so quickly. Presently it is running through a 3/4 copper tube that is buried in the concrete slab. It is a double whammy - since it is in concrete and not insulated - you lose heat thru the heat sink - and since it is 3/4 copper the tube holds much more water. Harry
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• posted on March 16, 2005, 2:08 am
Let me write this down first you are probably right and I worked a hard day today.
7/8 Refrigeration equals.........3/4 Plumbing
I just bought a few hundred refrigeration fittings today too!
My bad, thanks for the correction. My brain is right my hands are stupid today
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Bob Pietrangelo
snipped-for-privacy@comcast.net
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• posted on March 15, 2005, 7:45 pm

Dear William - Thanks for the chart. I appreciate all the work. Does that mean 100 feet of 3/4 inch holds .282 gallons? 1/2 inch holds .120 gallons? 1/4 inch holds .026 gallons? I expected 100 feet of pipe to hold so much more. Harry
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• posted on March 15, 2005, 8:12 pm
Harry Everhart wrote:

No. That's CUBIC FEET. Gallons per 100 ft are: 0.9, 2.1, 0.2
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• posted on March 15, 2005, 8:05 pm
On Tue, 15 Mar 2005 13:05:04 -0500, Harry Everhart
(ID/2) x 3.1416 x (pipe length)
Just guessing.....
tom
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• posted on March 15, 2005, 8:40 pm
www.WorkAtHomePlans.com> wrote:

Not a good guess. The formula is A = pi * radius SQUARED, not pi * radius / 2.
-- Regards, Doug Miller (alphageek at milmac dot com)
Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?
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• posted on March 16, 2005, 12:01 am
Regarding;

I agree with Doug: i.e. pi times, the radius raised to the power 2 (squared) So; Inside diameter divided by two = Radius of X.Section. In this case one half divided by 2 = one quarter. Area of X.Section = Radius squared, multiplied by pi. This is one quarter times one quarter times pi = 1/16 x 3.142 = 0.196 Length of 100 feet = 100 x 12 inches. Thus (1/4 x 1/4 x 3.142 x 1200) = 236 cubic inches. Multiply that 236 by 0.004 to get gallons = 0.9 gallons approx. (Not sure if that's US or Imperial gallons but "A bit less than a gallon" is close enough). Anybody else agree? BTW those 236 cubic inches will weigh approx 8.5 pounds. Those 8.5 pounds will require 8.5 BTUs for every degree Fahrenheit change of temperature. So if that 8.5 lbs comes out of the tank at temperature of, say, 160 degrees, sits in the pipe and cools down, to say 60 degrees it will lose 100 x 8.5 = 850 BTUs of heat. If electrically heated that's equivalent to about one quarter of a kilowatt hour (unit) of electricity. If your electricity costs 10 cents per kilowatt hour that's a waste (sort of) of 2 to 3 cents. Of course that heat, slight though it is, could end up helping to heat the house! BTW There is a very good site at < www.tedmongomery.com/convrsns/ > for those NOT too lazy to look it up! PS. In school we remembered circular area by "Two are(a) squared pies". i.e. Pies were normally round; not square. Even if we were!
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• posted on March 16, 2005, 12:34 am
snipped-for-privacy@milmac.com (Doug Miller) writes:

So in terms of ID, the formula is: pi*(ID/2)*(ID/2) where pi=3.14159....
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• posted on March 16, 2005, 2:45 pm
blueman wrote:

The table I published above used the formula =PI()*(B2/2)^2 in the Excel spreadsheet. The B column holds the Inside Diameter. Excel supplies the right value for pi.
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• posted on March 17, 2005, 1:41 pm
On Tue, 15 Mar 2005 20:40:22 GMT, snipped-for-privacy@milmac.com (Doug Miller) wrote:

Caught it after I posted it, that's why I reposted it.
Thought the second post would 'over-write' the first. Hmmmmmm......
later,
tom
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• posted on March 15, 2005, 8:07 pm
On Tue, 15 Mar 2005 13:05:04 -0500, Harry Everhart
(ID/2)^2 x 3.1416 x (pipe length)
So should be radius squared times pi times length of straight tube.
hth,
tom
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• posted on March 15, 2005, 8:07 pm

Yes, we do.
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• posted on March 15, 2005, 8:31 pm
Edwin Pawlowski wrote:

LOL. I was somewhat surprised to see Harry get all of the help he did get, after that remark. Now. Who's he going to get to do the work? ;o)
... This is a good group of people.
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• posted on March 15, 2005, 9:08 pm

People can sense honestly. :-)
I really like this group - no one ripped me - and I got great answers. Now I must decide whether I want to run 100 feet of 1/4 inch - 1/2 inch - 3/4 inch to a kitchen sink and dishwasher 100 feet away from the tankless water heater. The tube will be overhead and insulated.
Opinions on that?
Harry