Glycol Chiller Doesn't Cool Below 43F/6C

[Iowa Brewer]

Hi all,

My BrewBuilt Max 2 & Spike CF10 combo never cool my beer below 43F when cold crashing.
Thinking ice build-up might be the issue, I've already tried the following.

1. Cooling the glycol to no less than 28F
2. Cooling in stages to prevent ice build-up, 10°F at a time

Being between brews, I just completed a water test. I filled the chiller with 6gal, just covering the thermo-well, and set the temp to 38F. No ice formed (good), but it never went below 43F (bad). Sadly, I can't remember my glycol/water ratio (whatever the webs said, I suppose).

Anyone else run into this? Any advice would be greatly appreciated!

 

[kgranger]

Maybe it's the full moon or something, but I am having almost the exact same issue haha!
If I learn anything from the post I made, I'll pass it along

 

[bailey mountain brewer]

How is your flow direction arranged?

 

[SonomaBrewer]

Had the same problem with my Spike conical. It's an issue with any conical because of the cooling coil mechanism.

Make sure you use insulated tubing, and make it as short as possible. I wasn't able to get below 38 until I realized the heat gain between the chiller and the cooling coil. I also throw a moving blanket over the conical now when it is cold. Even insulated, every square inch of stainless (especially the lid) is a heat sink.

 

[Iowa Brewer]

Maybe it's the full moon or something, but I am having almost the exact same issue haha!
If I learn anything from the post I made, I'll pass it along

Thanks, Kgranger! Hope we get this sorted

 

[Iowa Brewer]

How is your flow direction arranged?
View attachment 816923

Thanks, Bailey Mountain Brewer! Yes, I have been using this diagram, but to no avail, sadly.

 

[Iowa Brewer]

Had the same problem with my Spike conical. It's an issue with any conical because of the cooling coil mechanism.

Make sure you use insulated tubing, and make it as short as possible. I wasn't able to get below 38 until I realized the heat gain between the chiller and the cooling coil. I also throw a moving blanket over the conical now when it is cold. Even insulated, every square inch of stainless (especially the lid) is a heat sink.

Thanks, SonomaBrewer!
My tubing is insulated with the foam padding that came with the tubes, from Spike. Maybe I'll reenforce those with some towels and duct-tape to see if that helps. I'll try the blanket, too.
I also wonder if it might work better with 10gal of water in there and less dead-air space, which I'm also going to experiment with.

 

[DonT]

Water cools better than glycol, but it will freeze. Glycol won't freeze, but it won't go as low as water... same thing in cars.
I'm just about to set up my new Penguin chiller and I'll probably go with a 60/40 water/glycol mix and see how that works...

 

[Jag75]

Just curious but how much beer do you have in your fv? What is the ambient room temp of the room ?

 

[Iowa Brewer]

Just curious but how much beer do you have in your fv? What is the ambient room temp of the room ?

Hi, Jag75. I usually have 6-7gal in there, and my brewroom is usually around 65-75F. Any ideas?

 

[bailey mountain brewer]

Hmm, 6-7 gallon in a fermenter that max is 14 gallon, with a chilling coil I'm willing to bet that not enough of the coil is touching the wort. You probably have several inches of "unused" coil. I bet if you put 10 or more gallons in there the cooling factor would improve greatly. Even though spike says it's good for 5 to 10 gallons. Just my thoughts.

 

[Jag75]

Hmm, 6-7 gallon in a fermenter that max is 14 gallon, with a chilling coil I'm willing to bet that not enough of the coil is touching the wort. You probably have several inches of "unused" coil. I bet if you put 10 or more gallons in there the cooling factor would improve greatly. Even though spike says it's good for 5 to 10 gallons. Just my thoughts.

This is exactly where I was going .

 

[Bobby_M]

This is basically why I hate glycol cooling at the homebrew scale. If you put the CF into a refrigerator, you can get the whole unit to 0F if you wanted to and it doesn't piss condensation all over your floor in the process.

 

[SonomaBrewer]

Getting the CF into (and out of) a refrigerator is the problem Bobby. I moved to glycol because of the havoc that my chest freezer and then my refrigerator were reeking on my back.

Glycol works well for fermentation temp control, but it is a lot tougher to dial in for cold crash. But you can definitely get there.

 

[Bobby_M]

Getting the CF into (and out of) a refrigerator is the problem Bobby. I moved to glycol because of the havoc that my chest freezer and then my refrigerator were reeking on my back.

Glycol works well for fermentation temp control, but it is a lot tougher to dial in for cold crash. But you can definitely get there.

There's always a way. Put the fermenter in the fridge and pump the wort in with a hose. I'm not saying refrigerators don't have their own problems, but I'll take it over glycol any day unless I need 3+ fermenters chilled all at the same time.

 

[Jag75]

I use a DIY glycol chiller with my CF5. Works flawlessly. There is some condensation(when crashing) where the glycol lines connect to the lid but I set a washcloth right under the connectors.

 

[bailey mountain brewer]

2 cf15s for me, 1 ssbrewtech glycol chiller. Sorry but for the size and quantity this is the way to go for me. When I was doing 5 gallon batches it was in a fridge. My setup is in my basement, they sweat a little during cold crash but the rest of the time no problem, and I run a dehumidifier down there anyway so no big deal to me.

 

[kgranger]

How much would glycol pump speed affect the cooling? I, having a similar issue with crashing temps, am using a small little aquarium pump to get glycol through the cooling coil, speed is pretty slow. Would a higher speed be beneficial, or is slow the way to go?

 

[CottonBrew]

I’ve also spent some time trying to optimize the Spike TC100 to get the performance I expected. I have two CF10’s and a Penguine ½ HP chiller. I believe part of the issue is insulation of the fermenter. I use a sleeping bag to fully cover the fermenter including attachments and legs which is an easy insulation addition.

Glycol concentration also affects cooling performance. I did flow testing at various glycol concentrations using the Spike glycol hoses and temperature coil. Glycol was pumped out of my Penguine chiller at 26F, through the temperature coil, and returned to a measuring container. Pump run time was one minute and the volume discharged was averaged over 4 test runs. The table below shows the results.

Pump	50% Glycol (Gal/min)​	25% Glycol (Gal/min)​	15% Glycol (Gal/min)​
CF101	0.326​	0.578​	0.744​
CF102	0.340​	0.566​	0.717​

The data shows an important consideration is optimizing glycol concentration for the chiller set point. Twice the flow rate is achieved using 15% glycol vs 50%. At 15% glycol the coils of my chiller iced up and would not cool below 30F, so I believe glycol should be > 15% for a Spike cooling system. I run my chiller at 25% glycol although 20% may be OK, but I would not go lower than 20%.

Optimizing glycol concentration and using a sleeping bag for insulation has allowed me to lower cold crash temperatures ~3F. When cold crashing I set the Penguine controller to 26F and the Spike TC100 controller to 35F, although my Tilt reads ~32F.

 

[cdug619]

Give it a good shake and see if the temp drops. I thought the same thing on my set up. I've noticed quite a bit of temperature stratification during cold crashing when the wort isn't moving from fermentation. I have a chronical and with a Tilt floating at the top, the SS probe in the probe port and my heater probe at the bottom, I saw quite a difference in temp ranges.

 

[SanPancho]

This is basically why I hate glycol cooling at the homebrew scale. If you put the CF into a refrigerator, you can get the whole unit to 0F if you wanted to and it doesn't piss condensation all over your floor in the process.

^this

Side x side fridge to ferm chamber FTW!

 

[BBeerme]

Although I'm not really familiar with the equipment y'all are using, I do A/C and refrigeration by trade, might be able to give you a couple of simple guidelines. Looks like you are inserting a cold coil into the beer (?).

First and foremost, insulating everything is the most simple and cost effective way to improve efficiency.

Regarding temps, your flow might be a major problem. Some basic rules of thumb go like this: A temp difference of 10*F is standard. In your refrigeration device, the refrigerant will be 10*F colder than your glycol heat transfer solution. You want the outlet temp of the glycol from your heat exchanger to be 10*F colder than the beer you are cooling. So . . .

If the outlet temp of the glycol cold coil is more than 10*F colder, slow down the glycol flow. If the temp difference is more than 10*F warmer, speed up the flow.

If you can't get the temp difference up to 10*F (glycol cold coil return to the chiller Vs beer temp) colder than your beer, then you do not have enough capacity in your chiller.

 

[Iowa Brewer]

Hmm, 6-7 gallon in a fermenter that max is 14 gallon, with a chilling coil I'm willing to bet that not enough of the coil is touching the wort. You probably have several inches of "unused" coil. I bet if you put 10 or more gallons in there the cooling factor would improve greatly. Even though spike says it's good for 5 to 10 gallons. Just my thoughts.

That sounds like a solid hypothesis, bailey mountain brewer

 

[Iowa Brewer]

Although I'm not really familiar with the equipment y'all are using, I do A/C and refrigeration by trade, might be able to give you a couple of simple guidelines. Looks like you are inserting a cold coil into the beer (?).

First and foremost, insulating everything is the most simple and cost effective way to improve efficiency.

Regarding temps, your flow might be a major problem. Some basic rules of thumb go like this: A temp difference of 10*F is standard. In your refrigeration device, the refrigerant will be 10*F colder than your glycol heat transfer solution. You want the outlet temp of the glycol from your heat exchanger to be 10*F colder than the beer you are cooling. So . . .

If the outlet temp of the glycol cold coil is more than 10*F colder, slow down the glycol flow. If the temp difference is more than 10*F warmer, speed up the flow.

If you can't get the temp difference up to 10*F (glycol cold coil return to the chiller Vs beer temp) colder than your beer, then you do not have enough capacity in your chiller.

Thanks, BBeerme!