Author Topic: Home Glycol system  (Read 6708 times)

Offline phillamb168

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Home Glycol system
« on: June 29, 2011, 08:10:01 AM »
The living room isn't big enough for more than a 2-keg kegerator, and I want to have more than that available at any time. I figure glycol is a good way to do it, but them things cost $$$$. Has anyone ever done a home-made glycol system? It seems like basically you need a pump that can handle continuous operation, some glycol, a way to cool the glycol, and some pipe insulation and electrical tape, basically. This seems like it would be an excellent DIY project, but I wanted to see if anybody else had done it before...

As an aside, I'm also going to try to machine my own draft tower. Already got the angle grinder, taps and stick welder, so the cost should be way less than the $400 KegWorks wants for a multi-tap glycol-ready tower.

...or am I nuts? I HATE BOTTLING.
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Offline dak0415

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Re: Home Glycol system
« Reply #1 on: June 29, 2011, 08:23:07 AM »
How many kegs do you want to have available?  Do you not have chest freezers in France.  Just have a secondary kegerator (fridge) in your brewery that will handle 4 or 5 kegs, and just keep the beer your wife wants to drink in the house.  If you use a stand-up fridge, you won't need a tower.
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Offline jeffy

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Re: Home Glycol system
« Reply #2 on: June 29, 2011, 09:58:44 AM »
I saw a commercial brewery that had a home made glycol set-up to chill 10 bbl a fermenter.  He had a small freezer with a temp controller in it to regulate the temperature of the glycol and a pump to circulate it to the fermenter.  Pretty cool, I thought, but he has since upgraded.  I don't think it could support more than one fermenter.
Is your idea to put the beer in an adjacent room and run lines to your living room?  If so you could pump cold air through the same tubing you run the beer lines.  I remember seeing a write-up of a project like that once.  I think the beer was on the floor below or in the basement.
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Offline tschmidlin

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Re: Home Glycol system
« Reply #3 on: June 29, 2011, 10:29:47 AM »
BYO did an article on it a couple of years ago.  I know a guy who built one, but I never saw it.  I haven't been in touch with him in a while and I recently saw he was selling all of his brewing equipment.  No one seems to know what happened, or they're not saying.  :-\

Google has some resources, but I don't know if they are any good.
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Offline phillamb168

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Re: Home Glycol system
« Reply #4 on: June 29, 2011, 10:52:43 AM »
Oops, I forgot to specify: this would be going in my basement/wine cellar, which is directly below the living room and stays at a pretty constant 60-65 deg F.

There are chest freezers here, but they're expensive (7 cu ft = 350 euros +) and too big, otherwise I'd put it in the living room with a collar. I'm getting the chest freezer as long as it would be feasible to run the lines up the 10 feet or so from the keg to the dispensing system. The other option is to just keep the kegs sitting in the cellar and chill the beer at the tap like a jockey box. I know you get foam when you take carbonated beer from cold to warm, but what happens in the other thermal direction?

... of course, I suppose I could build a bracket system to mount the keezer to the ceiling of the cellar...  :o ::)
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Offline tumarkin

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Re: Home Glycol system
« Reply #5 on: June 29, 2011, 02:48:30 PM »
yeah, mount the keezer to the ceiling and the taps could then be mounted on the floor... maybe right next to the couch. just a short run, the beer would stay nice & cold. maybe just use a muffin fan to circulate cold air from the keezer into the tap tower. you wouldn't even need to get up to get a beer. sweet!!! ;D
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Offline Joe Sr.

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Re: Home Glycol system
« Reply #6 on: June 29, 2011, 02:57:38 PM »
Phil - I ran through the same thought process as you when we remodeled our kitchen a couple years back.

I had full approval to put taps in the kitchen, but couldn't figure a good way to bring the beer up from the basement below.  I did think about suspending a fridge from the ceiling in the basement, but only briefly...

In the end, I decided short trips to the basement for draft beers wasn't too bad of a way to live.  The glycol system seemed to be just too much effort, cost, etc. and the cold plate would have required dedicating some cabinet space to a wine fridge.  Obviously, suspending a fridge from the ceiling of the basement just wasn't practical.

If you get your system worked out, let us know.  I'd love some taps in the attic, as it's a long way to go from there to the basement to get a draft...
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Offline lupulin5446

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Re: Home Glycol system
« Reply #7 on: June 29, 2011, 03:42:50 PM »
To glycol cool the lines from your cellar, you will need to put together a 'python', a recirculation pump, a reservoir, and a cooling device.  The cooling device can be a small refrigerator, as you will want your glycol to be only slightly colder than your beer.  The Inner diameter of the coolant line should be larger than your draft lines to avoid burning up your pump.  To construct your 'python', simply loop your coolant line so that the intake and return portions run parallel, but end at the same point.  Lay out your draft lines parallel to the coolant lines, and attach threaded fittings to both ends.  Wrap the whole assembly into 1 bundled cable with insulated tape.  If you can not find it, try finding a more generic insulation, and wrap it in uninsulated tape.  Be sure to give yourself some extra length when constructing your python.  Place the reservoir inside the cooler and recirculate the glycol.  To clean the draft lines, link them in series with fittings, turn off the glycol pump, and recirculate hot caustic. 

An issue you must consider when pushing beer up from a cellar is the head pressure in your kegs.  You will be fighting both gravity, and the friction in your draft lines.  If you use your normal pressure settings, you will likely notice a greatly decreased flow rate.  Increasing the head pressure will over carbonate most of your beers, so your only option would be to use draft lines with a larger diameter because of the lower friction coefficient.  Unless, of course, you want to use mixed gas.  You should note that the glycol lines will keep your beer cool on its journey to your glass, but will not effectively cool warm beer.

I hope this is helpful.

Offline phillamb168

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Re: Home Glycol system
« Reply #8 on: June 30, 2011, 02:25:30 AM »
To glycol cool the lines from your cellar, you will need to put together a 'python', a recirculation pump, a reservoir, and a cooling device.  The cooling device can be a small refrigerator, as you will want your glycol to be only slightly colder than your beer.  The Inner diameter of the coolant line should be larger than your draft lines to avoid burning up your pump.  To construct your 'python', simply loop your coolant line so that the intake and return portions run parallel, but end at the same point.  Lay out your draft lines parallel to the coolant lines, and attach threaded fittings to both ends.  Wrap the whole assembly into 1 bundled cable with insulated tape.  If you can not find it, try finding a more generic insulation, and wrap it in uninsulated tape.  Be sure to give yourself some extra length when constructing your python.  Place the reservoir inside the cooler and recirculate the glycol.  To clean the draft lines, link them in series with fittings, turn off the glycol pump, and recirculate hot caustic. 

An issue you must consider when pushing beer up from a cellar is the head pressure in your kegs.  You will be fighting both gravity, and the friction in your draft lines.  If you use your normal pressure settings, you will likely notice a greatly decreased flow rate.  Increasing the head pressure will over carbonate most of your beers, so your only option would be to use draft lines with a larger diameter because of the lower friction coefficient.  Unless, of course, you want to use mixed gas.  You should note that the glycol lines will keep your beer cool on its journey to your glass, but will not effectively cool warm beer.

I hope this is helpful.

Could I not keep the reservoir in the same keezer as the kegs? I'm guessing I can run the glycol through some 1/2" ID food-grade tubing? Or does it need something larger/different tubing type? And in terms of the pump, can I use a regular March pump (or a large aquarium pump), or does it need to be something special?

The build seems simple in principle - it's basically a radiator, right?

Pump and tubing costs I can reckon, but how much does glycol cost, and how much might I need? 2-3 gallons? And it HAS to be polypropylene glycol, right? Aaaand finally - could I just use a 1/2 water, 1/2 cheap vodka mixture? Glycol is basically alcohol with an extra OH-group (yes, I know this makes it entirely different) but they both share the ability to be chilled below freezing and still remain liquid.

Where's da Weaze - I thought he used to be an HVAC guy.

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In terms of pushing the beer, most commercial bars go at minimum the distance I'm going from cellar to living room, so how do they get the beer up there without over-carbing it? Could I use a pressure regulator to vent excess CO2 between dispensing? Other than using beer engines, of course, but I'd prefer to use my existing taps if possible.
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Offline tom

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Re: Home Glycol system
« Reply #9 on: June 30, 2011, 10:18:55 AM »
I would think that keeping a water tank in the fridge would be the most economical.  Water actually works better than glycol.  They just add glycol to be able to get the temp below freezing.

For the balancing, you will still carbonate to your desired carbonation volumes and adjust the serving line resistance to "balance" the system.  You'll probably use some 1/4"  ID hose in the beginning of the line and just enough 3/16 ID at the end to balance.
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Offline tschmidlin

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Re: Home Glycol system
« Reply #10 on: June 30, 2011, 10:38:58 AM »
In terms of pushing the beer, most commercial bars go at minimum the distance I'm going from cellar to living room, so how do they get the beer up there without over-carbing it? Could I use a pressure regulator to vent excess CO2 between dispensing? Other than using beer engines, of course, but I'd prefer to use my existing taps if possible.
They use either bigger tubes (1/4" or bigger like Tom mentioned above) to cut the resistance so you can serve at the same pressure as you carbonate with, or they use mixed gas.  N2 is about 80 times less soluble in beer than CO2 is, so using a blend of gases can let you push a long way without over carbonating the beer.  Unless you have some place near you that does custom gas blends, I think a larger tube is the way to go.

Assume you're going up 12 feet . . . 144 inches, Jeff R pointed out in another thread that 1 psi will raise a column 27 inches, so 5.3 psi to overcome that.  If you carb at 12 psi, that leaves 6.7 psi for the hose.  So you want a hose that gives you 0.56 psi resistance per foot.  morebeer's 5/16" says 0.40 lbs per foot, the 1/4" says 0.65 lbs per foot.  You can pick one and tweak the carb pressure/temp, and of course the actual height might be a couple of feet different.  I'd start with figuring out the height.
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Offline lupulin5446

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Re: Home Glycol system
« Reply #11 on: June 30, 2011, 03:11:30 PM »
In terms of pushing the beer, most commercial bars go at minimum the distance I'm going from cellar to living room, so how do they get the beer up there without over-carbing it? Could I use a pressure regulator to vent excess CO2 between dispensing? Other than using beer engines, of course, but I'd prefer to use my existing taps if possible.
They use either bigger tubes (1/4" or bigger like Tom mentioned above) to cut the resistance so you can serve at the same pressure as you carbonate with, or they use mixed gas.  N2 is about 80 times less soluble in beer than CO2 is, so using a blend of gases can let you push a long way without over carbonating the beer.  Unless you have some place near you that does custom gas blends, I think a larger tube is the way to go.

Assume you're going up 12 feet . . . 144 inches, Jeff R pointed out in another thread that 1 psi will raise a column 27 inches, so 5.3 psi to overcome that.  If you carb at 12 psi, that leaves 6.7 psi for the hose.  So you want a hose that gives you 0.56 psi resistance per foot.  morebeer's 5/16" says 0.40 lbs per foot, the 1/4" says 0.65 lbs per foot.  You can pick one and tweak the carb pressure/temp, and of course the actual height might be a couple of feet different.  I'd start with figuring out the height.

A hose that gives 0.56 psi resistance per foot based on a 12 foot hose would make the liquid static at the top of the draft tower.  Even 0.40 psi/foot would give a slow flow rate.  I would guess that 3/8 I.D. would be minimum, and perhaps restrict it to a smaller size for the last 4-6 inches.  Another option is to elevate the freezer as close as possible to the ceiling without making keg changing too cumbersome.

BTW, it would be more efficient to keep the coolant reservoir with the kegs, but I recommended keeping the coolant a bit cooler because there will always be some heat loss in the python, which can lead to foaming.  Restricting the draft lines at the end can help combat foaming though.

Offline tschmidlin

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Re: Home Glycol system
« Reply #12 on: June 30, 2011, 03:24:10 PM »
A hose that gives 0.56 psi resistance per foot based on a 12 foot hose would make the liquid static at the top of the draft tower.  Even 0.40 psi/foot would give a slow flow rate.
Systems are typically balanced so that the pressure at the tap is zero.  According to the draft beer quality manual "When applied pressure equals resistance, a draught system will pour clear-flowing beer at the rate of 2 ounces per second."

He needs to take into account the resistance of the components in the tower, the faucet, etc, but ultimately he's still shooting for zero at the tap.
Tom Schmidlin

Offline lupulin5446

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Re: Home Glycol system
« Reply #13 on: June 30, 2011, 04:46:12 PM »
It seems your knowledge of Newtonian physics may be lacking...If pressure on the liquid is equal to the total resistance, then there can be no flow.  The only way you can get liquid to flow this way is if you have gravity on your side.  If the volume of liquid is above the spout on the tap, then gravity would cause the liquid to flow out (like a siphon).  If the mass of liquid is below the spout, than nothing will happen.  The only other thing that would cause the beer to flow if the pressure at the spout is 0, is the decarbonization of the beer.  An open spout will cause a pressure drop that will drive an excessive amount of CO2 out of solution, resulting in a steady flow of beer, and a glass full of foam.

Offline tschmidlin

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Re: Home Glycol system
« Reply #14 on: June 30, 2011, 07:30:27 PM »
I understand physics pretty well, thanks, but it is hard to argue with results.  If you don't believe the Draft Beer Quality Manual, published by the Brewers Association, that's cool with me.  No one is ever required to believe someone just because they are an authority on the subject (not me, the BA).  But the nice thing is you can always try it yourself and see what happens.

I suspect one of the reasons it works is that they use some rounding and the tubing resistance numbers you get are usually high.  For example, the DBQM says to allow 0.5 psi per foot of height, which is high (for water at 62F it's 0.433 lbs/ft).  And morebeer says their PVC tubing has a resistance of 2.2 lbs/ft, which in my experience is too high.

So unless you are actually going to go to the trouble of measuring the resistance in your system, you can go by the guidelines provided by the parts suppliers and shoot for zero at the taps and get a good pour.  I've found it is best to start with an even longer line than calculated and cut it back until you get the pour you want.

If you wanted to, from there you can add a hose to the end of the faucet and see how high the beer rises in it, then back calculate the actual pressure at the tap.  But that is just an exercise that would only be useful in the future if you had perfect knowledge of the resistance of every component.  Physics only works if you can plug in the right numbers.

@Phil - don't forget to account for the actual length of the line, not just the rise.   You'll want at least a few feet in the cooler to make it easier to tap kegs.
Tom Schmidlin