41 replies to this topic

[ChefLamont]

What pumps are you using in the propylene glycol? I thought propylene glycol caused stress cracking in certain plastics.

They are basic fountain pumps from harbor freight.I will have to check into that. I was not aware of that.

[gnef]

quick search found this:httpss://dow-answer.custhelp.com/ci/fattach/get/11972/I tend to think you will be fine. If you ever have issues, just buy another pump from harbor freight.

[davelew]

quick search found this:httpss://dow-answer.c...tach/get/11972/I tend to think you will be fine. If you ever have issues, just buy another pump from harbor freight.

Yeah, if you have any problems, just buy another pump and maybe look into reducing the glycol concentration from 40% to 25%. It looks like 25% is the limit for both PVC and CPVC. Also, acrylic has a surprisingly low max temp in glycol-- your system probably won't ever hit 90 degF, but I can think of many cooling systems that might reach 90.

[Mynameisluka]

so, i was cruising around the old internet trying to find some ideas for cooling a sanke fermenter. right off the bat, google directed me where? right here to this thread. way to go brews-bros!

 

im thinking of modifying cheflamont's cooler to go low-tech. i want to use a cooler with a couple of frozen 2 liter bottles (water) to cool glycol. the glycol would be pumped through a coil wrapped around the sanke and wrapped in insulation...much like chef lamont's model. the only real difference would be that instead of using the a/c to chill the glycol, i would use the 2 liters. i figure i really only need it to stay cool for a week or so, and I could easily take the 2 liters out and refreeze them during the process if needed. the temp would be regulated with a controller with the probe in a thermowell in the keg. the glycol would be pumped through the coil with a submersible pump in the cooler.

 

will this work? or, am i crazy?

[Mynameisluka]

actually, i would just use water instead of glycol.

[ChefLamont]

If you are only doing ale temps, I think water would be fine and you could make it work with soda bottles.

 

For that matter, you could freeze tupperware containers and just put those blocks of ice in the water (you dont have to worry about diluting glycol) that way you could have more freezing as you chill.  You would just have to take the extra volume out as you go.

 

As long as you are not trying to crash chill it or maintain a huge deltaT, this should work fine.

[Mynameisluka]

Would there be any advantage to using glycol instead of water in this setup?

[ChefLamont]

For ale temps, no not really.  Propylene glycol is used so you can get temps below 32F and still have a liquid that is non-toxic.

 

Edit: You won't get the water to 32 with ice, so there is no point.  Plus, for the cost and potential mess, doesnt seem worth it.

 

 

Plus if you build it and it doesnt perform as desired, you can always add glycol and some sort of chiller down the road.  You will already have the cooler and some of the pumps.

Edited by ChefLamont, 05 June 2013 - 12:57 PM.

[Mynameisluka]

For ale temps, no not really.  Propylene glycol is used so you can get temps below 32F and still have a liquid that is non-toxic.

 

Edit: You won't get the water to 32 with ice, so there is no point.  Plus, for the cost and potential mess, doesnt seem worth it.

 

 

Plus if you build it and it doesnt perform as desired, you can always add glycol and some sort of chiller down the road.  You will already have the cooler and some of the pumps.

 

 

cool, that's what i was thinking...thanks for the help! i may upgrade to the full blown unit like you have one day. but, for now i only do ales. i may tinker around with a heater in the garage in the winter to get the temps right for a lager. how is your setup working for you? 

[ChefLamont]

Use the same cooler/pump setup with an aquarium heater in the water instead of the ice.  Done.

[Clintama]

Glycol will help stop mold and other nasties from forming.

[Jdtirado]

Damn anyone who understands this and more importantly can build it sucks! JK I'm so jealous

[ChefLamont]

Oh come on.  We havent even begun to talk about the thermodynamics of this yet.  That's when it will get fun fun fun.

 

If we start talking about heat capacities of water and glycol, I will probably get all tingly. 

[Mynameisluka]

Oh come on.  We havent even begun to talk about the thermodynamics of this yet.  That's when it will get fun fun fun.

 

If we start talking about heat capacities of water and glycol, I will probably get all tingly. 

 

water >> glycol.  

 

if i add some clorox to the water to prevent mold, i shouldn't have much of oxidation/corrosion of the copper since the bleach will be so dilute and the solution with be so cold, right?

[ChefLamont]

 

water >> glycol.

 

if i add some clorox to the water to prevent mold, i shouldn't have much of oxidation/corrosion of the copper since the bleach will be so dilute and the solution with be so cold, right?

 

 

If you are talking drops per gallon probably.  I would worry as much about parts in the pump.  However, the reality is if you eat up a pump every year or two, the cost is not overwhelming.

[MyaCullen]

bump

[SchwanzBrewer]

I've had aquarium pumps last for years, it's all you should need.

[3rd party JKor]

Dang, i can't believe i missed this the first time around. Even though '12-'13 was during the height of my hiatus, i'm still surprised. I've been thinking about doing the exact same thing ever since i did my first AC cooled ferment chamber, probably almost 10 years ago. Nice work, Chef!

Updates? Is the PG fermenter still kicking?

[Stout_fan]

I obtained a water cooler (freon compressor type not peltier) when the one at work sprung a leak in the hot water side. I'm hoping this has enough BTUs to cool a 25 gal batch. Any ideas?  Or do I need to go big; like your big honkin' AC unit?

 

And great info on dilution, specific heat and glycol crazing.  THANKS!

 

Bought 4 gallons of RV antifreeze at Wallyworld for $2.67 each.

Edited by Stout_fan, 07 August 2015 - 05:50 AM.

[3rd party JKor]

Just a guess, but I would think a water cooler is pretty low power.  Although they are generally compressor based, so it's probably not tiny like a peltier.  I would just assume it's much less than a 5kbtu AC.