Chiller blanket proof of concept.

[J A]

I've been thinking about various strategies for cooling carboys and other 5 gallon batch fermenters. I'll have glycol chilling capacity but that only works on my bigger fermenter that are equipped with chiller coils. For carboys and buckets or small conical I need some way to pump glycol to chill outside the container. There are some bladder type chiller blankets at various price points but I keep thinking that DIY solution would be pretty easy.
I thought about tubing wrapped around the fermenter and covered with some insulation and I'm sure that would work. The notion of more contact surface led me back to the bladder/blanket option. I realized that I have the technology to do that in the form of my vacuum bag food storage sealer. By using parchment paper as a blocker I can us the sealer to make baffles and tubing inlets.
I have to refine the design and process but initial test shows that I can produce a bladder that I can pump fluid through.

 

[Minbari]

The trick with that would be termination. how will you connect tubing to it?

I would think silicon tubing or even bicycle tire tube wrapped around it might work. a barb and pipe clamp would be easy to seal either one.

Maybe daisy chain a bunch of hot water bladders together (the rubber ones used for sore muscles)

 

[J A]

I'll post a pic of the layout I'm using. It's possible to make a "spout" at each end that can have a tube inserted and clamped. I've definitely thought about the tubing but the surface area is pretty skimpy. A coil on the inside in contact with the liquid is great but tubing that's trying to cool the carboy has a harder time of conducting heat and cold. The bag will have a comparatively huge contact are and be much more efficient. If it holds up, I wouldn't be surprised if I could crash a carboy down to lagering temps. I'm making a full-size version that I'll wrap around a carboy and do some stress testing and see if the seals will hold up and not develop leaks.

 

[Minbari]

I'll post a pic of the layout I'm using. It's possible to make a "spout" at each end that can have a tube inserted and clamped. I've definitely thought about the tubing but the surface area is pretty skimpy. A coil on the inside in contact with the liquid is great but tubing that's trying to cool the carboy has a harder time of conducting heat and cold. The bag will have a comparatively huge contact are and be much more efficient. If it holds up, I wouldn't be surprised if I could crash a carboy down to lagering temps. I'm making a full-size version that I'll wrap around a carboy and do some stress testing and see if the seals will hold up and not develop leaks.

That would be my concern. you don't have alot of pressure moving the glycol, but even 3-4psi can push liquid out.

@ $45 a gallon, i wouldn't want to lose it, lol

 

[J A]

Leak testing in progress. So far nary a drop gone astray. I'm running sanitizer through it. Not sure it'll hold up to cold liquid but I have a lot of vacuum bags in the freezer for many months at a time.

 

[Donoroto]

You can always find heavier plastic film.

 

[Dave Y]

@J A

I was just thinking about something like this for my garage setup. I have a dual glycol chiller but can’t break the TX summer heat once we get into the 100’s regularly. I was thinking about this.
What if I repurposed the 2nd set of chiller ports, connected to 8mm tubing, wrapping the fermenter and under the neoprene jacket?

hmmm...

 

[Dermotflyn]

I've been thinking about various strategies for cooling carboys and other 5 gallon batch fermenters. I'll have glycol chilling capacity but that only works on my bigger fermenter that are equipped with chiller coils. For carboys and buckets or small conical I need some way to pump glycol to chill outside the container. There are some bladder type chiller blankets at various price points but I keep thinking that DIY solution would be pretty easy.
I thought about tubing wrapped around the fermenter and covered with some insulation and I'm sure that would work. The notion of more contact surface led me back to the bladder/blanket option. I realized that I have the technology to do that in the form of my vacuum bag food storage sealer. By using parchment paper as a blocker I can us the sealer to make baffles and tubing inlets.
I have to refine the design and process but initial test shows that I can produce a bladder that I can pump fluid through. papa's scooperia
View attachment 31323

Using your vacuum sealer to create custom bladders for better contact surface area is a clever idea, and it should enhance the cooling efficiency. Refining the design will definitely help optimize the performance!

 

[Dave Y]

Just to follow up, I wrapped my 14 gallon Blichmann fermenter with the above mentioned 8mm tubing, particularly the bottom portion part way up the cone to the height of the handles. It looks like that alone is enough for holding about 20F below ambient. That won’t be enough by itself, but that was never the plan. I have two possible plans.

1) Split one circuit of my chiller and run input to the main cooler; a drop in coil that’s about an inch in diameter and the 8mm tubing. That should even out the temperature but I’m not sure it will be enough flow.
2) Use both circuits of the chiller, one for the 8mm ‘jacket’ cooler and the other circuit for the main chiller.

I believe this has potential, but if I have to go with option 2, I need to put another temp sensor in the wort or come up with some sort of hack to engage both circuits - it doesn’t flow coolant without a temp signal. If it works I’ll port the idea to my 7 gallon, and with lower volume to cool, I have high hopes.
It’s been a little too cool at night to test my theory but I should have a test run in a week or so.