Deciding on DIY glycol chiller bath size

[Sean_SA]

Hi guys

I'm in the process of building a DIY glycol chiller with a 13000 BTU portable air conditioner. I need this chiller to service 6 x 350L fermenters. Each with a 13 meter 3/8" coil

As usual the bath will be a cooler box but I'm unsure of what size the cooler should be seeing as this is a 13000BTU compressor.

I've placed the evaporator in a 48qt coleman cooler and the evaporator takes up too much space in the cooler and leaves no room for pumps. So what I'd like to know is if there is a specific guideline I can follow with regards to cooling power and the adequate bath size for that. Or is that factor not really that important?

I'm gonna have 6 pumps in the cooler so will need space for them as well as a recirculation pump.... I have a 100qt coleman xtreme cooler here that I'm happy to repurpose for the job but is 100qt overkill?

 

[Bobby_M]

shoot a picture of what it looks like with the 48qt cooler. Are you sure you can't fit the pumps in there? They don't have to be arranged neatly nor do they require any space between them.

 

[postalbunny]

Do yourself a favor... if you're chilling more than 3-4x fermenters then use one pump and build a glycol distribution. That way you can use one hose, and use solenoids to turn a valve on/off for each fermenter rather than using pumps for each fermenter.

it'll be cheaper and easier in the long run with that many fermenters.

 

[Sean_SA]

Do yourself a favor... if you're chilling more than 3-4x fermenters then use one pump and build a glycol distribution. That way you can use one hose, and use solenoids to turn a valve on/off for each fermenter rather than using pumps for each fermenter.

it'll be cheaper and easier in the long run with that many fermenters.

Thanks yes this was the consensus among ourselves at the end as well. In your opinion, what single pump would be suitable to handle the load?

 

[postalbunny]

Yeah, just size the pump ... not sure on the math for GPH and how many you have. I have 2 fermenters and use a 1600gph pond pump that cost aprox $75 (Amazon.com).

I used 1/2" pvc to build the manifold, 4 "outputs" with a 1/2 ball valve and 4 "inputs" after. The 1/2 provides a path for glycol to flow so you don't over stress your pump. I put a PSI gauge on and keep pressure at 3-4psi on the "out" side. Then i used cheap $20 solenoids from amz (https://www.amazon.com/gp/product/B018WRJYUO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1) that are powered by inkbird wifi controllers for each fermenter.

Bonus side, on brew day I can use one of the out/in pairs for a 1st stage heat exchanger since ground water in texas gets in upper 90f during summer time.

The alternative would be trying to shove enough pumps "in" the resevoir and having an "out/in" to the reservoir for each one. It's probably possible, but once you have more than 3-4x Fermenters seems like a waste.