Closed system Counterflow chiller ideas and build

[frettfreak]

I want to build a closed system counterflow chiller and looking for some feedback and suggestions from the people in the know about this stuff. I already have a 50' counterflow chiller and honestly it works amazing. In the summer i have to hook it up to a pre-chiller that is submerged in an ice bath, but wort comes out at pitching temps or lower (in the winter if i use a prechiller i can get as low as 55 coming out). However, i am in CA, and with the drought going on i would really like to make an all inclusive / closed system but trying to figure out the best way to go about it. I have a couple options in mind but always open to suggestions.

I will not ever do a no chill and just let it sit though so please dont suggest it (just too many opportunities to mess up the beer).

I do have an old dehumidifier that i could disassemble and would give me a radiator to use and whatever else i can pull from it but the compressor may be shot (it trips a breaker when i turn it on). I also have a couple pumps that i could use (a 1/4 hp and a 530gph pump)

Here are my thoughts:

1. Use the radiator submerged in ice and an inline pump to move a water/glycol mixture through the cfc. this seems to me like it would work, but would love to find a way to do this without using a bunch of ice.

2. use the radiator with some fans and shrouds to cool the liquid as it passes through and push to the CFC. My concern with this would be that it just wouldnt cool the liquid enough to get the results i am looking for.

3. Use a cold plate and a couple peltier coolers to chill the liquid as it passes though and recirculates though the cfc. my concern with this would be the peltier setup. its been many years since i used a peltier cooler (long ago in my PC modding days), and just dont have much experience with electrical wiring and what i would need to accomplish this.

those right now are my main ideas, but like i said, fire away if you have a better one. I can throw some money into it if i need to but seems like i have most of what i need already. really seems like one or all of these would work, feel free to poke holes in them so i can avoid any issues.

If i can make it small enough to be portable that would be a HUGE plus. thinking maybe self contained unit inside a cooler for portability

thanks in advance!!

 

[Bellybuster]

all the effort you're looking into to chill the cooling liquid needs to be spent on chilling the wort. Spend the effort on the foremost job.
is the radiator made of stainless???

 

[frettfreak]

all the effort you're looking into to chill the cooling liquid needs to be spent on chilling the wort. Spend the effort on the foremost job.
is the radiator made of stainless???

my wort will be chilled by the wort CHILLER (cfc) that i already have.... it works... i just need a way to chill the liquid that is flowing through the outside of my CFC. Up until this point it has been water either straight from a hose, or ran through a prechiller first. it works REALLY REALLY well... but like i mentioned i live in CA and they are putting lots of restrictions on my water use. I am just looking for a way to be for water friendly and still get good results. which means finding a way to chill the liquid that will be cooling the wort.

Likely the radiator is aluminum cause it transfers heat better. No need for stainless as my wort will NEVER touch it.

 

[jmpreiks]

I'm not really sure if this would be practical, and I haven't run the numbers, but it seems like you could have a couple 5+ gal pails of glycol solution that you made very cold with a chest freezer and pump it through the CFC.

The heat capacity of glycol solution is less than water but you can get it colder so there a trade-off there that would have to be figured out.

Seems easier than trying to actively cool the glycol at least, not sure how energy efficient this method is though. Note that I have zero practical experience in such things (other than an engineering degree)... so take my ideas with a grain of salt.

 

[frettfreak]

I'm not really sure if this would be practical, and I haven't run the numbers, but it seems like you could have a couple 5+ gal pails of glycol solution that you made very cold with a chest freezer and pump it through the CFC.

The heat capacity of glycol solution is less than water but you can get it colder so there a trade-off there that would have to be figured out.

Seems easier than trying to actively cool the glycol at least, not sure how energy efficient this method is though. Note that I have zero practical experience in such things (other than an engineering degree)... so take my ideas with a grain of salt.

i did think about this and have the fridge to cool the glycol if needed... but the more i keep thinking about it, the more i think a couple peltier coolers on a cold plate is the answer i am looking for. the peltiers can get down into the negative degrees on the cold side as long as i am properly dissipating heat from the hot side so in theory, I would think that as long as the plate chiller has enough channels and is keeping the solution in contact with the plate chiller long enough to dissipate the heat, it should work.

the problem is, i know that this could all be calculated before i spend the cash... i just dont have the degree or knowledge in electrical engineering to figure it out! lol

 

[Stealthcruiser]

Just a wag here, but I don't think you would get the cooling "buffer" that you would need, with the Peltier deal.

By "buffer", I don't think an easily "affordable" Peltier, that could handle the heat rejection needed in a timely manner.

No heat management knowledge / engineering degree, or any of that other stuff here!

 

[WScottCross]

I have some experience with Peltiers and I don't think they will be able to help significantly. You would need A LOT of them to cool the water significantly, or you need a really slow flow rate.

The best bet will be an ice bath. Be aware that it will probably take 40+ lbs of ice to chill a 5 gallon batch.

 

[Homercidal]

Peltiers would be awful in this application. They can get cold, but they wouldn't be much use with this much hot wort. I think you are underestimating the thermal mass of a batch of hot wort.

The radiator idea is probably way more effective, but I'm not sure how it would end up working in a real test. If you are already taking that radiator apart it seems simple enough to rig up a test. Living in Cali you are probably still looking at using ice for at least part of the year if you want to conserve water.

I personally think that you might be best off conserving water using a few different methods. Remember that to get the real benefit of chilling you only need to get the wort down below about 140F. After that the only thing you need to worry about is infection and that's hardly a real concern if your system is mostly closed.

So I'd think about collecting the really hot water from the start of the chill in a large container. You can then re-purpose the water later for a variety of things. Then I'd switch to a pump and a large container of icewater to get the chill down as far as you can. You'll likely still use excess water this way, but if you are willing to capture it, it's not technically going to waste.

If you have a fermentation chamber or a cool spot in the house I'd try to get the wort down to below 140F and wherever a reasonable amount of chilling gets you, then put it in the ferm chamber to finish cooling to pitching temp with a filter in the airlock port. They make special filters to keep bacteria and stuff from getting into your fermentor. They are only a few dollars each. You could probably then pitch later in the evening or the next day. I've used them before when concerned about suckback when chilling overnight and they seem to work very well.

Yep, dealing with a water shortage in a PITA.