BigTexBrewer
Active Member
I have noticed that some people put their CO2 in their kegerator while some people have them outside of it. My kegerator is set up to do both so is there a plus or minus to either situation. Thanks.
CO2 in or out of kegerator
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shortyjacobs
Well-Known Member
CO2 inside the kegerator:
Plus - Less affected by temp swings if your kegerator is in the garage, (like mine). If the temp changes drastically, I have to re-check my regs on my outside mounted CO2 to make sure they still are putting out the right pressure.
Minus - Takes up room in the kegerator, (less beer room!), and can be more difficult to access to check/change pressures depending on how you mount it.
CO2 outside the kegerator
Plus - More room inside, easier access.
Minus - Subject to temp swings if in the garage.
That's all I can think of. Mine is mounted outside for ease of access and to allow 6 kegs in my fridge.
Plus - Less affected by temp swings if your kegerator is in the garage, (like mine). If the temp changes drastically, I have to re-check my regs on my outside mounted CO2 to make sure they still are putting out the right pressure.
Minus - Takes up room in the kegerator, (less beer room!), and can be more difficult to access to check/change pressures depending on how you mount it.
CO2 outside the kegerator
Plus - More room inside, easier access.
Minus - Subject to temp swings if in the garage.
That's all I can think of. Mine is mounted outside for ease of access and to allow 6 kegs in my fridge.
BigTexBrewer
Active Member
Since air gets denser when cold, will that effect the PSI or amount I need to set the pressure at?
shortyjacobs
Well-Known Member
No.
Density of the CO2 isn't the issue here. The only things that affect carbonation are pressure and temperature, (temperature of the BEER, NOT of the CO2...CO2 temperature does not matter). Pressure is pressure, regardless of the temperature of the CO2.
So if you were going to set your regulator at 14 PSI with the regulator outside of the fridge, set it at 14 PSI inside the fridge too.
One thing to note is, at least with my regs, temp changes change the setpoint. So if you have your regulator set at 14 PSI, THEN put it into your fridge, go check it a couple hours later to make sure it's still set at 14 PSI....in my case I have to adjust it once it's reached fridge temp.
Density of the CO2 isn't the issue here. The only things that affect carbonation are pressure and temperature, (temperature of the BEER, NOT of the CO2...CO2 temperature does not matter). Pressure is pressure, regardless of the temperature of the CO2.
So if you were going to set your regulator at 14 PSI with the regulator outside of the fridge, set it at 14 PSI inside the fridge too.
One thing to note is, at least with my regs, temp changes change the setpoint. So if you have your regulator set at 14 PSI, THEN put it into your fridge, go check it a couple hours later to make sure it's still set at 14 PSI....in my case I have to adjust it once it's reached fridge temp.
This is a great point, one I learned the hard way. When I first got a kegerator, my beer was consistently overpressured, and I didn't understand why.
BigTexBrewer
Active Member
Thanks for the info. I can't wait to keg my first beer this weekend.
Hethen57
Well-Known Member
I don't know why this is, but since I moved my C02 tank outside the keggerator (to make more room for beer)...it has lasted much longer. I think you are able to run it down more gradually for a long time at the end of the tank. When it was cold, it seemed like the reg was either in the green, or it dropped to zero fast.
shortyjacobs
Well-Known Member
This is you getting scared by the high pressure gauge. The pressure in the headspace of the CO2 tank is affected by pressure. At 70F, it's around 800 PSI. At 40F, it's around 400 PSI. 400 PSI is usually where the "Red Zone" starts on those gauges, and why people freak out about their tanks being empty.
In reality, that gauge is useless. Unlike a gas gauge in a car, this gauge basically tells you only one thing: Is there CO2 or not? If there's CO2, it will read a certain amount based on temperature. As you use CO2, THE READING WON"T CHANGE, because more liquid CO2 in the tank boils to replace the vapor you are drawing off. All of a sudden, when you run out of CO2, the pressure will quickly drop to 0. Of course, the pressure on your regs will ALSO drop to 0, so you don't really need the high pressure gauge at all.
The amount of carbonation in beer is a "molecules" thing. No matter what the temp of the supply CO2 in the tank, 5 gallons of beer will take on 12 gallons of CO2 measured at STP (standard temperature and pressure), to reach 2.4 volumes of carbonation. 12 gallons @ STP = 1.89 moles. No matter what the temperature of the CO2 is, it will always take 1.89 moles of CO2 to carbonate your beer to 2.4 volumes, (assuming 5 gallons of beer).
There is a set number of moles of CO2 in your tank, (5 lbs worth, 10 lbs worth, whatever size your tank is), therefore your tank can carbonate and dispense a set number of kegs worth of beer, regardless of the temperature it's at (within reason.....drop the temp of your tank below the boiling point of CO2, and you'll have problems, but that's -57°C, so no worries).
Hethen57
Well-Known Member
Cool...thanks for the great explanation! I probably was filling my tank way too early when it was cold and in the "danger" zone. The paranoia is warranted...you don't want the weekend to come (the gas store is closed), and your buddies stop by for a homebrew and you can't serve 'em beer....haha.
shortyjacobs
Well-Known Member
Yeah, I definitely know what you mean. Really though, you can run the CO2 tank dry without much of a problem. (If you run the tank dry, then continue to serve beer, then you'll drop headspace pressure and start to decarb your beer...but as long as you catch it within a day or two, and you'll know because your regs read low and your beer pours slow, you're fine).
I just grabbed a second tank. My 15 lb tank is my "main" tank, since it costs $15 to fill, and my 10 lb tank is my "backup", since it costs $14 to fill.
Of course, when the 15 pounder runs out, I usually switch to the 10, and run that until IT runs out, and then have to go swap them both at the same time, but the theory is sound at least.
heckels
Well-Known Member
$15 for a 15lb tank? Damn, that's cheap. I pay $18 for a 5lb tank and haven't found anyone nearby that's any cheaper...
shortyjacobs
Well-Known Member
Yeah, it's a welding supply shop near me. I just called all the welding supply shops in the area and found the cheapest. It's $13 for a 5#, $14 for 10#, $15 for 15# I think.
