Glycol-Chiller Ice Buildup

[Iowa Brewer]

I’m cold crashing 7.5 gallons of beer in my CF10, using a homemade glycol chiller.

Yesterday it went down to 33°F. Now it seems stuck at 40°F, although the solution temp is measuring at 14°F.

I used the recommended glycol:water ratios, but there’s ice buildup on the evaporating coil. Is this a problem?

As always, thanks!

 

[Jag75]

Looks like that coil isn't fully submerged. The lowest I've had mine down was in the 20's. A submersible fan that keeps the solution moving might help . If it's getting ice I would think the glycol % is too low . I don't know at what temp it freezes.

Do you have the hose correlation correct for cold crashing?

 

[Golddiggie]

What ratio/percentage solution are you using? I ended up going stronger on the glycol in my mixture. That lowers the freezing temperature of the mixture.

What temperature is your target inside the fermenter? If you really want the beer to be at 33F (keep in mind, the beer closer to the chill coils will be colder than that by the time the rest gets to that temperature where the sensor sits) you'll want a stronger mixture. A 20% glycol solution has a freeze point of about 16-17F. Which means you need a higher concentration of glycol to be good. I typically run mine at about 22F in the reservoir to get my carbonating temperature (36-38F).

This might help you:

If you're looking to have the solution at 14F you'll want a 30% solution/mixture. I went with the 25% mixture in my chiller.

 

[Iowa Brewer]

Looks like that coil isn't fully submerged. The lowest I've had mine down was in the 20's. A submersible fan that keeps the solution moving might help . If it's getting ice I would think the glycol % is too low . I don't know at what temp it freezes.

Do you have the hose correlation correct for cold crashing?

thanks, Jag75! Can’t remember the ratio I used, but should prevent ice (I’ve been known to miscalculate). I’m going to buy (so expansive!) and add some my glycol to the mix

 

[Iowa Brewer]

What ratio/percentage solution are you using? I ended up going stronger on the glycol in my mixture. That lowers the freezing temperature of the mixture.

What temperature is your target inside the fermenter? If you really want the beer to be at 33F (keep in mind, the beer closer to the chill coils will be colder than that by the time the rest gets to that temperature where the sensor sits) you'll want a stronger mixture. A 20% glycol solution has a freeze point of about 16-17F. Which means you need a higher concentration of glycol to be good. I typically run mine at about 22F in the reservoir to get my carbonating temperature (36-38F).

This might help you:
View attachment 752152

If you're looking to have the solution at 14F you'll want a 30% solution/mixture. I went with the 25% mixture in my chiller.

Thanks, Golddigge!
Can’t remember the ratio, but should’ve been good for quite cold temps. Obvs not good enough, eh? I’m going to buy more and fill it up a bit more.

I followed Spike’s recommendation and am setting it to 38F. Hopefully it all comes out right in the wash.

 

[Golddiggie]

thanks, Jag75! Can’t remember the ratio I used, but should prevent ice (I’ve been known to miscalculate). I’m going to buy (so expansive!) and add some my glycol to the mix

I'm using the IceMaster Max 4 now with a reservoir capacity of 8-1/2 gallons. I didn't fill it up initially because I wanted enough room to add more later. Got about 7-1/2 gallons in it currently. When I had the previous chiller (max 2) I did have icing on the coils inside the chiller when I set it too low. I increased the ratio and that went away. It's also important to know what the sweet spot is for getting your fermenter to the desired temperature. If you go too cold in the chiller, it actually doesn't work as well. It seems a bit upside down, but that's how it seems to work. Of course, if your lines aren't well insulated, you'll have thermal loss there. The thin insulation of the lines from Spike is way too little IME. I have 1/2" wall foam insulation on the lines from/to the chiller and chill coil in fermenter. Pretty much eliminates condensation on the lines and reduces thermal loss to the air during transit.

BTW, are you changing the glycol flow route between maintaining fermenting temperature and when you want to go below 40F? I've had mixed results doing that. Sometimes it seems to work, others not so much.

 

[Jag75]

If you look at your Spike manual there is a diagram for switching the glycol in line when cold crashing . I'll see if I can find it . My mixture is 7 gallons of distilled and 3 gallons of glycol . You ain't lying , that stuff is expensive.

 

[IslandLizard]

there’s ice buildup on the evaporating coil. Is this a problem?

The ice forming on top of the non-submerged part of the evap coil is water vapor from the air inside the coolant reservoir. May have also to do with splashing.
To prevent that, you need to add more coolant, indeed.

 

[Golddiggie]

The ice forming on top of the non-submerged part of the evap coil is water vapor from the air inside the coolant reservoir.

Looked (to me) like the ice was also on the submerged part.

 

[Tom R]

Circulating with an aquarium wave-maker keeps mine from icing up.
Amazon.com: FFXTW 1PCS Aquarium Wave Maker Power Head Circulation Pump ,Wavemaker for aquariums fish tank filter with Suction Cup… : Pet Supplies

 

[IslandLizard]

Looked (to me) like the ice was also on the submerged part.

Yes, you're right, and much more so than the thin frosting on the top! Looks like a big solid clump.
Had to zoom in to see it...

 

[Iowa Brewer]

I'm using the IceMaster Max 4 now with a reservoir capacity of 8-1/2 gallons. I didn't fill it up initially because I wanted enough room to add more later. Got about 7-1/2 gallons in it currently. When I had the previous chiller (max 2) I did have icing on the coils inside the chiller when I set it too low. I increased the ratio and that went away. It's also important to know what the sweet spot is for getting your fermenter to the desired temperature. If you go too cold in the chiller, it actually doesn't work as well. It seems a bit upside down, but that's how it seems to work. Of course, if your lines aren't well insulated, you'll have thermal loss there. The thin insulation of the lines from Spike is way too little IME. I have 1/2" wall foam insulation on the lines from/to the chiller and chill coil in fermenter. Pretty much eliminates condensation on the lines and reduces thermal loss to the air during transit.

BTW, are you changing the glycol flow route between maintaining fermenting temperature and when you want to go below 40F? I've had mixed results doing that. Sometimes it seems to work, others not so much.

Great idea on the 1/2" insulation. I'm going to give that a go!
I haven't changed the flow between fermenting temp and cold crashing. I just have an aquarium pump in my Igloo cooler, so not sure how to do that.

 

[Iowa Brewer]

If you look at your Spike manual there is a diagram for switching the glycol in line when cold crashing . I'll see if I can find it . My mixture is 7 gallons of distilled and 3 gallons of glycol . You ain't lying , that stuff is expensive.

Woah! That's super interesting! I'm going to switch them around when I get home. Thanks!

 

[Golddiggie]

Great idea on the 1/2" insulation. I'm going to give that a go!
I haven't changed the flow between fermenting temp and cold crashing. I just have an aquarium pump in my Igloo cooler, so not sure how to do that.

You just shift the connections to the chill coil. Easy peasy. I bought some of the thicker insulation from Amazon, for 1/2" OD tubing. But when I shifted to the silicone tubing (5/8" OD) I bought the insulation from McMaster. Bought enough for all four line sets on the Max 4. Only using two currently (the other pair of barbs are connected with a loop).

Something else (as a FYI). If you want to be SURE that your lines don't dump solution when disconnected, buy some 3/8" OD tubing (I'm using stainless), and cut a piece (about 3-4" long works) to join the connections when you remove them from the chill coil. I do this for the pair of lines that are setup. That way I can hang them aside and not worry that if the pump(s) turn on, I'll dump solution all over the basement floor. This is especially handy when you go to clean out your fermenter.

 

[Tom R]

I use valved disconnects, similar to these. They shut off the flow when disconnected, I get just one drop when I separate them to clean my conical.
Very convenient.
valved disconnects | U.S. Plastic Corp. (usplastic.com)

 

[Tom R]

I use valved disconnects, similar to these. They shut off the flow when disconnected, I get just one drop when I separate them to clean my conical.
Very convenient.
valved disconnects | U.S. Plastic Corp. (usplastic.com)

Whoops, I see those ones are not rated for cold temps.
The acetal versions are good for -40F.

 

[Golddiggie]

I use valved disconnects, similar to these. They shut off the flow when disconnected, I get just one drop when I separate them to clean my conical.
Very convenient.
valved disconnects | U.S. Plastic Corp. (usplastic.com)

I get maybe a couple of drops when I remove the connections from the coil, if done properly. The stainless tubing is also a lot cheaper than getting a pair of those connections. Especially since you have enough for at least a few sets with a single 12" long piece.

 

[Golddiggie]

BTW, to go from the 3/8" ID silicone tubing to the Spike PTC connections for the chill coil, I simply used pieces of 1/2" OD stainless tubing. Forced one end into the tubing, and the other goes into the PTC without issue. IIRC, I pushed about 1-2" of the silicone tubing over the stainless tubing to be sure it wasn't going anywhere. It will stretch to take it.

I need to get one more section of tubing to build up the set for the fourth pair of barbs on the Max 4. No rush to do that, since I only have two fermenters at present.

 

[superiorsat]

Yesterday it went down to 33°F. Now it seems stuck at 40°F, although the solution temp is measuring at 14°F.

If you know for sure your pump is pumping and your solution is a 14 F you most likely also have a big block of ice built up over your coils in the fermenter. This would then be like chilling with a big ice cube at 32 degrees fighting ambient temp from the sides of the fermenter. On the 2 chillers I built I managed to get the coil flat enough to the bottom that it can easily be completely submerged. On water test runs only as long as I slowly lowered my temp to 33 degrees for the chiller I was able to bring a 35 gallon ace-roto tank from 68 to 38 degrees with no glycol and no block of ice on the AC coil. Eventually I'll get to using these 2 units with glycol just don't need them quite yet so can't chime in on glycol ratios.

 

[JAReeves]

You just shift the connections to the chill coil. Easy peasy. I bought some of the thicker insulation from Amazon, for 1/2" OD tubing. But when I shifted to the silicone tubing (5/8" OD) I bought the insulation from McMaster. Bought enough for all four line sets on the Max 4. Only using two currently (the other pair of barbs are connected with a loop).

Something else (as a FYI). If you want to be SURE that your lines don't dump solution when disconnected, buy some 3/8" OD tubing (I'm using stainless), and cut a piece (about 3-4" long works) to join the connections when you remove them from the chill coil. I do this for the pair of lines that are setup. That way I can hang them aside and not worry that if the pump(s) turn on, I'll dump solution all over the basement floor. This is especially handy when you go to clean out your fermenter.

I have been wondering what I could use, this is a great idea! Thank you!

 

[Iowa Brewer]

Thank you all, so much, for your ideas. This was extremely helpful.
In the end, I added more glycol to the mix and it seems to have worked.

Before, the window-ac unit I used to build my chiller was running non-stop. Now the ice-jam on the evaporating coil is gone and its MUCH more efficient. I'm also going to beef-up the insulation over the outflow and return tubes.

Happy brewing, everyone!

 

[Golddiggie]

This is the insulation I bought for the 3/8" ID silicone lines (5/8" OD): McMaster-Carr

 

[Iowa Brewer]

This is the insulation I bought for the 3/8" ID silicone lines (5/8" OD): McMaster-Carr

Cheers!