How Long Should a 10# CO2 Tank Last?

[ultravista]

How long should a 10# CO2 tank last?

 

[TopherM]

A 5# tank lasts me about 3-4 months, and I brew about 2-3 batches a month, so about 10-12 brews for a 5#, ERGO, a 10# should go about 20-24 batches, which is about a year for a fairly active brewer.

 

[philipCT]

Interested in this answer too. I've got a 5lb tank that is lasting much longer than I expected. It's my first one so there was some "learning" (waste through loose connections) in there too.

So far I've carbed four cornies worth and have roused hops on two batches and CO2 filled a bunch of bottles I filled for a competition. It's close to redline now so I have a full tank on standby, but it's still kicking. I can't really draw any conclusions from my experience so far though because my use has been so mixed.

 

[ACbrewer]

sorry questions like this bring out the geek in me. I thought, hmm.. better question, how much volume should a pound, or 10# of CO2 take up. Found this
"How much volume does 1 kg of CO2 occupy at room temperature and standard pressure?
CO2 has a molecular weight of 44 g/mol
1 kg CO2 = 1000 g × (1 mol/44 g) = 22.7 mol CO2
V=nRT/P, V=(22.7)(0.0821)(300)/1 = 559 L CO2 at 27°C (300K), 1 atm
This is a little more than half a cubic meter approximately equal to the volume of two
bathtubs or the trunk of a large car."

right, in a ballpark area, we have about 559L of CO2 at room temp for 1kg of CO2. OR in standard 5# and 10#, and reduced to a 5 gallon standard we get
559L/3.7L/G*5Lb/2.2lb/kg=about 343 gallons div 5 (gallons per keg) is about 42 corny. So depending on your usage, you should get 42 corny volumes out of this. Call it 40 for several reason. this means a 5# should have enough CO2 to fill 40 cornies. Beer is servered usually in the 2.5 volumes of disolved CO2 (which means that there is 2.5 kegs volume worth of CO2 disolved in the beer - go gas compression). Ok and +1 to get it out - so abou3.5 per batch - yeilds about 11 to 12. out of a 5# CO2.

And similarly 22 to 24 for a 10#. There are some issues. the formula above (pv=nrt) that I quoted is the 'ideal gas law' and is like all science at that level, it is simplified to make the math easier and teach the idea. And generally gets a 'close enough' answer. Second, the temp used is 27C which is room temp (about 68) and not serving temp of beer. Third this assumes serving at 2.5volumes, I know some beer goes as high as 3.5+ and some as low as 2. the point of this exercise is to get an idea.

Lastly, I was surprised it came out to what Topher said his experience showed 10-12. But hey Science, it works!

 

[Beer-lord]

My 5lb tank lasts me about 6 months brewing about 2 times a month. Alot of things affect how long your tank lasts and I always check for leaks each time I add a keg.

 

[atom]

mine lasts 15-20 kegs (used to force carb and dispense)... when i don't have a leak.