Long Draw system? Need mixed gas?

I'm hoping to have my keezer in the basement and run the beer and glycol lines through the floor and up to my draft tower. The run might be 12'-15'.
Will I run into problems with over carbonated beer (foam) becuase the CO2 will be difussing into the beer as it trys to push the beer that far up from the kegs? I'm hoping to avoid mixed gas. Maybe I have no choice. Aanybody else run into this? Thanks

Have you read this?

https://files.pbworks.com/download/PiIBwXoW6Z/draftquality/47312934/DQM Full Final V2.pdf

It gives you an idea of what you need to do to balance your system based upon length of line and height you need to push. One thing that I've seen quite a bit online is that 3# of resistance for 3/16" beverage tubing is generally assumed to be high. If you assume 1.5-2# resistance it might help a bit to get the right number.

Get some 1/4 inch or bigger tubing! The resistance per foot goes way down with bigger ID.

Hi

You probably will be fine with 3/16 line, 15 to 20 feet is not an unusual level run. With 1/4" line you may need to add a bit of tubing. 40+ foot runs are not uncommon with 1/4".

The next issue will be setting up the lines so they are adequately insulated as they make the run. You might consider running them in PVC pipe to make pulling the foam coverd lines easier.

Bob

carlisle_bob said:

15 to 20 feet is not an unusual level run. With 1/4" line you may need to add a bit of tubing. 40+ foot runs are not uncommon with 1/4".

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I understood OP's situation as needing 12-15 feet of vertical run, not level run. 12' of vertical run will cancel out half the pressure on the keg right there before you factor in line resistance.

SpartyParty, half the time you hear that the line balancing equations never work out anyway, so I'd just experiment. Maybe just fill a keg with some water and push it out through 1/4" and 3/16" tubing with your expected serving PSI and measure the flow rate at the faucet? Based on that you can figure out what size tubing to buy in bulk.

zachattack said:

I understood OP's situation as needing 12-15 feet of vertical run, not level run. 12' of vertical run will cancel out half the pressure on the keg right there before you factor in line resistance.

SpartyParty, half the time you hear that the line balancing equations never work out anyway, so I'd just experiment. Maybe just fill a keg with some water and push it out through 1/4" and 3/16" tubing with your expected serving PSI and measure the flow rate at the faucet? Based on that you can figure out what size tubing to buy in bulk.

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Hi

... thus the term "level run" in the post..

I do beleive that with 1/4" he'll need more than 15 feet of line. Since it's probably bundled glycoll line, it's not cheap stuff.

Bob

Thanks for all the help! The plan was to go with a trunk line like the ones on micromatic.com comes wrapped in vapor barrier, foil, and insulation. the beverage lines (1/4") are wrapped around the glycol lines, see the photo. I won't be pushing beer 12' vertical there will be some horizontal runs in there. assuming my basemnet is 7' and the tower will be 4' from the floor and the kegs will be about 4' off the floor as i will have them in a fridge with the freezer on bottom and fridge on top so my vertical run might no be more than 8' feet or so.

So it sounds like my run should be small enough that I SHOULD be able to tweak the system to work and not have to worry about a nitro/co2 mix...? For those that are wondering I plan on having a pump in a bucket in the freezer below the fridge. Amazing how big these fridge types are. After measuring I should be able to fit 6 kegs and the co2 or a 7th keg.

Another way to look at this:

It takes about 2.3psi to lift water (or beer) on vertical foot. So, if you are lifting the beer 10 vertical feet, you will have to add 23psi just to get the beer to the faucet without any actual flow. A few more psi will be required to make the beer flow at a reasonable rate, so let's call it 30psi.

At 30psi and 40 degrees F, you will be running about 4 volumes of CO2 which is pretty high for most beers. If this were my setup, I would definitely consider mixed gas. You can get a nitrogen tank and regulator at harbor freight for not much over $100 with coupons and the gas is only slightly more expensive.

Adam

adamreef said:

Another way to look at this:

It takes about 2.3psi to lift water (or beer) on vertical foot. So, if you are lifting the beer 10 vertical feet, you will have to add 23psi just to get the beer to the faucet without any actual flow. A few more psi will be required to make the beer flow at a reasonable rate, so let's call it 30psi.

At 30psi and 40 degrees F, you will be running about 4 volumes of CO2 which is pretty high for most beers. If this were my setup, I would definitely consider mixed gas. You can get a nitrogen tank and regulator at harbor freight for not much over $100 with coupons and the gas is only slightly more expensive.

Adam

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Sorry, but this is wrong. It takes 0.43 PSI per foot to lift water. One inch of water = 0.036 PSI. The rule of thumb for balancing a keg system is to assume 0.5 PSI per vertical foot.

That's why above I said that a vertical gain of 12 feet would roughly cancel out half his serving pressure. 1/4 inch ID polyethylene tubing has a resistance of roughly 0.5 psi/foot so with 12 feet of line, 12 feet of vertical gain he's looking at a 12psi drop which should be good to go. In practice things might work a little different, sometimes the resistance is less than you think so he may need more tubing to cancel it out, as Bob mentioned.

zachattack said:

Sorry, but this is wrong. It takes 0.43 PSI per foot to lift water. One inch of water = 0.036 PSI. The rule of thumb for balancing a keg system is to assume 0.5 PSI per vertical foot.

That's why above I said that a vertical gain of 12 feet would roughly cancel out half his serving pressure. 1/4 inch ID polyethylene tubing has a resistance of roughly 0.5 psi/foot so with 12 feet of line, 12 feet of vertical gain he's looking at a 12psi drop which should be good to go. In practice things might work a little different, sometimes the resistance is less than you think so he may need more tubing to cancel it out, as Bob mentioned.

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So if my normal serving pressure is say... 4 or 5psi i would need to add .5psi per foot (lets assume about 10 feet vertical) then another .5psi per foot of line resistance... so I could serve it at say 14 or so? Maybe I'm not understanding the math...?

What I'm looking for is it waste of my time to drill a hole in my wall and run line if I'm not willing to spend the money on a gas blender? If there is a chance that i can use only co2 and balnce it out and not have over carbed beer I'm willing to try it and see if i can balance it out. Thanks again!

Subscribed to this. You're doing exactly what I'm planning on doing in a few weeks, except I'm fabricating my own trunk line and chiller.

SpartyParty said:

So if my normal serving pressure is say... 4 or 5psi i would need to add .5psi per foot (lets assume about 10 feet vertical) then another .5psi per foot of line resistance... so I could serve it at say 14 or so? Maybe I'm not understanding the math...?

What I'm looking for is it waste of my time to drill a hole in my wall and run line if I'm not willing to spend the money on a gas blender? If there is a chance that i can use only co2 and balnce it out and not have over carbed beer I'm willing to try it and see if i can balance it out. Thanks again!

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In a balanced system, your serving pressure should equal your carbonation pressure. For most people this is in the 12-14 PSI range, depending on the beer style, temperature, personal preference, etc. In a proper system there should be no need to change the pressure to serve.

According to the calculations, you should be fine with 1/4 inch tubing and pure CO2 pushing the beer out. I can't promise you it will work in practice... but I'm sure someone here's done it before

SpartyParty said:

So if my normal serving pressure is say... 4 or 5psi i would need to add .5psi per foot (lets assume about 10 feet vertical) then another .5psi per foot of line resistance... so I could serve it at say 14 or so? Maybe I'm not understanding the math...?

What I'm looking for is it waste of my time to drill a hole in my wall and run line if I'm not willing to spend the money on a gas blender? If there is a chance that i can use only co2 and balnce it out and not have over carbed beer I'm willing to try it and see if i can balance it out. Thanks again!

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Hi

There may be a disconnect here:

Your serving pressure (pressure coming out of the faucet) is always going to be 0 psi. The beer is in normal air at that point. You *want* it to get down to that pressure gradualy. Abrupt changes will make it foam.

If your beer is kegged at 4 or 5 psi that's a different issue. That's a very low carb beer. Most commercial beers are up in the > 12 psi range and a few are served as high as 18 psi. At 4 psi, there isn't going to be much carbonation at all...

Bob

zachattack said:

Sorry, but this is wrong. It takes 0.43 PSI per foot to lift water. One inch of water = 0.036 PSI. The rule of thumb for balancing a keg system is to assume 0.5 PSI per vertical foot.

That's why above I said that a vertical gain of 12 feet would roughly cancel out half his serving pressure. 1/4 inch ID polyethylene tubing has a resistance of roughly 0.5 psi/foot so with 12 feet of line, 12 feet of vertical gain he's looking at a 12psi drop which should be good to go. In practice things might work a little different, sometimes the resistance is less than you think so he may need more tubing to cancel it out, as Bob mentioned.

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zachattack, you are correct. I fail at scrutinizing quick google results. The numbers I grabbed agreed with my gut, so I didn't fact check. Thanks for the correction. My gut still says slow pours and/or higher than desired carbonation is likely, but maybe not to the point where it is a serious problem.

Also, FWIW, the reason that resistance is often different than expected is because the pressure drop due to the tubing itself varies depending on flow rate. Higher flow rates require greater pressure drop. Estimating .5psi per foot of tubing length is a very rough estimate which assumes a certain flow rate. That's why it ultimately takes some experimentation to tweak it just the way you want it.

SpartyParty, please keep us updated for posterity sake.

Adam

adamreef said:

zachattack, you are correct. I fail at scrutinizing quick google results. The numbers I grabbed agreed with my gut, so I didn't fact check. Thanks for the correction. My gut still says slow pours and/or higher than desired carbonation is likely, but maybe not to the point where it is a serious problem.

Also, FWIW, the reason that resistance is often different than expected is because the pressure drop due to the tubing itself varies depending on flow rate. Higher flow rates require greater pressure drop. Estimating .5psi per foot of tubing length is a very rough estimate which assumes a certain flow rate. That's why it ultimately takes some experimentation to tweak it just the way you want it.

SpartyParty, please keep us updated for posterity sake.

Adam

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Good point about resistance being a function of flow! I think you're right that OP should experiment. I think this will work, might need a bit of tweaking (increasing/decreasing extra line) but shouldn't require nitrogen.

Thanks for all the help guys! I may have been off with my "4psi serving" I carb most of my kegs between 8-12 psi. A few of you mentioned adding line to balance it out. When or why would I want to add line?

I think what i'm going to do is run about 12 feet of line from a keg full of water to a picnic tap and have the line at a 8 foot vertical. Then try and pour and play with it just to see if it works. If I can pull that off then it should work with the beer and the actual build. Is there any issue with testing using water and not carbed beer? I should have the line at the desried temp when running the test correct?

Thanks again! When I start the build I'll be sure to update the post. I have 6 tap brass tower I snagged from CL for $25. It was a mess and I cleaned it up and replaced two shanks. I'm pumped to give it some action!

SpartyParty said:

Thanks for all the help guys! I may have been off with my "4psi serving" I carb most of my kegs between 8-12 psi. A few of you mentioned adding line to balance it out. When or why would I want to add line?

I think what i'm going to do is run about 12 feet of line from a keg full of water to a picnic tap and have the line at a 8 foot vertical. Then try and pour and play with it just to see if it works. If I can pull that off then it should work with the beer and the actual build. Is there any issue with testing using water and not carbed beer? I should have the line at the desried temp when running the test correct?

Thanks again! When I start the build I'll be sure to update the post. I have 6 tap brass tower I snagged from CL for $25. It was a mess and I cleaned it up and replaced two shanks. I'm pumped to give it some action!

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Measure the flow (pour) rate when you're experimenting. A slower pour rate is what you want, if it comes screaming out of the faucet it means it's gonna be all foam if it's beer. Don't worry about temp, just measure flow rate.

For your other question, sounds like you need to read up on system balancing! This is something you should understand before you take on a project like this, once you understand why we're suggesting these things it'll be pretty obvious. There are some good guides online, here's one:

http://beersmith.com/blog/2011/07/14/keg-line-length-balancing-the-science-of-draft-beer/

zachattack said:

Measure the flow (pour) rate when you're experimenting. A slower pour rate is what you want, if it comes screaming out of the faucet it means it's gonna be all foam if it's beer. Don't worry about temp, just measure flow rate.

For your other question, sounds like you need to read up on system balancing! This is something you should understand before you take on a project like this, once you understand why we're suggesting these things it'll be pretty obvious. There are some good guides online, here's one:

http://beersmith.com/blog/2011/07/14/keg-line-length-balancing-the-science-of-draft-beer/

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Great article! If I carb at 12 ... doing the math (line) L = (12-1-(8/2))/.85 = 8.24 feet of lilne to achieve balance. I need at least 12 feet for my run. If I carb at 15 I get L = (15-1-(8/2))/.85 = 11.76 feet of line. Do you think that is too high to carb at 15? If the numbers are right I think I should be able to make this project come together with 12 feet of line and an 8 foot vertical by carbing/serving at 15psi. Of course the numbers might say one thing and the practical application be different. I'll try and run that test using water and measure the flow rate and post the results. Thanks again!

SpartyParty said:

Great article! If I carb at 12 ... doing the math (line) L = (12-1-(8/2))/.85 = 8.24 feet of lilne to achieve balance. I need at least 12 feet for my run. If I carb at 15 I get L = (15-1-(8/2))/.85 = 11.76 feet of line. Do you think that is too high to carb at 15? If the numbers are right I think I should be able to make this project come together with 12 feet of line and an 8 foot vertical by carbing/serving at 15psi. Of course the numbers might say one thing and the practical application be different. I'll try and run that test using water and measure the flow rate and post the results. Thanks again!

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Your math looks good, but those equations are notoriously inaccurate, and typically underestimate the length of line required to get a good pour. Also remember that they're designed to give the fastest possible pour without creating foam. Since it doesn't sound like you're running a bar or restaurant where the number of pints you can pour in an hour impacts your profit, a slightly slower pour won't hurt anything. Based on my own experiences and long draw projects I've seen on here, I think you'll be fine with pure CO2 and 12 psi. You may even find that you need longer than 12' of line to slow it down a little.