Cooling chiller, glycol system design

[xico]

I have a conical fermenter that I boil in. It has a jacket on it I can run tap water through to chill before pitching and maintaining fermentation temp control. The problem I am running into warm tap water as a challenge and I am sick of wasting water on the end of the cooling period.

The hope is to use tap water for the first 8 gallons (comes out hot and perfect for a split of pbw and then rinse water) which gets the temp to ~95F. Then I'd like to hook up a chilling system that has been cooling water/glycol in an insulated vessel and circulate this fluid for the remainder of the fermentation, conditioning, and subsequent crashing to 39ish F.

How powerful of a system am I looking at? What is most efficient? How large of a reservoir do I need in a cold liquor tank for a conical holding upwards to 80L and an 8L jacket? Is there another chilling system comparable in performance to glycol I'm not familiar with?

Thanks!

 

[ajdelange]

The problem you run into is that you have a huge cooling demand in getting wort to pitching temperature because you want to do that quickly. For example to lower 10 gal (84 lbs) of wort from 95 to 50 requires that you remove 45*83 = 3826 btu of heat. If you want to do that in a quarter of an hour the rate is 15300 BTU/hr which means a 1.3 ton unit. That's not a huge unit by any means but once you get to fermentation temperature the demand for cooling goes way down. Even when you are ready to crash cool that is done over days, not minutes and 1.3 ton would be overkill.

The obvious way to get the 3826 BTU out of the beer is to store 3826 BTU of 'cold' in a reservoir of some sort which contains water that you have chilled over night (say) with a much more modest sized unit. I let you do the math as there are a million approaches here. Just remember 1 BTU moves 1 pound of water 1 °F. A ton is 12,000 BTU/hr.

 

[GotPushrods]

Are you set on glycol? I tend to over-engineer just about everything, but for this I'm very happy pumping ice water from a 5-gal bucket.

I tend to get about 10* drop per bag of ice per 11 gallons. If my tap gets me to 90, that's 4 bags to pitching temp.

Once I reach a reasonably stable temperature I switch the feed from the hose bib to my pump in a bucket. The warm water goes back into the bucket. I fill it about half way with water then dump in 2 bags of ice. As the ice melts I add more as needed. I've chilled as low at 40* this way.

It's far and away the least sophisticated part of my brewery, but if it works...

 

[xico]

GotPushrods, I do something similar right now but I am not happy with buying bags of ice. I have a 20 gallon batch system so I need to utilize a 14 gallon vessel to drop ice in and I go through 4 bags to make it work.

ajdelange, that's what I had in mind. I was considering having a 10 to 15 gallon cooler that gets chilled down to 35F overnight, then pump it into the jacket and recirculate. I'm not set on glycol at all, I'm just exploring what's available out there. I know there are coolers at my school's brew lab that use a heat sink and two fans and that gets surprisingly down there.

 

[ajdelange]

Just want to add my thanks to xico for asking this question. I realized after thinking about if that taking my own advice (as given in No. 2) will solve a problem that has been plaguing me for some time. Wort comes out of my chiller in the 60's and I want to pitch at about 50 or a little below. I can store several gallons of water that I have cooled over night and that I could run through a second chiller (I even have an old one around) to drop that extra 10 or 15 degrees.

 

[xico]

Just want to add my thanks to xico for asking this question. I realized after thinking about if that taking my own advice (as given in No. 2) will solve a problem that has been plaguing me for some time. Wort comes out of my chiller in the 60's and I want to pitch at about 50 or a little below. I can store several gallons of water that I have cooled over night and that I could run through a second chiller (I even have an old one around) to drop that extra 10 or 15 degrees.

Thanks to you friend, maybe we can work this common issue out. I did the calculations and I have the BTUs needed. What I am unclear on is how to take this number to size my storage of cold fluid.

 

[MidAtlanticBrew]

My solution to this problem is a 1/10 hp JBJ Arctic aquarium chiller with a 30 gallon cooler. I prechill ~20 gallons of water to 35 F by circulating through the chiller with an aquarium pump. This is pump loop number 1. As AJ mentioned above ... This creates stored cooling capacity which is needed because 1/10 hp is only about 1200 BTU/HR.

My experience ... Temperature of 11 gallons in the fermenter is around 80 to 85 F. Fermenter has cools inside it (SS Brewtech). I set my temp controller to 64 for ales. Smaller pump (pump loop 2) circulate the cold water in the cooler through the coils in the fermenter. In 20 to 30 minutes, I'm at pitch temperature. In terms of holding fermetation or crash temps, I've had no problem keeping 22 gallons in three separate fermenters as low as 38 F

 

[xico]

My solution to this problem is a 1/10 hp JBJ Arctic aquarium chiller with a 30 gallon cooler. I prechill ~20 gallons of water to 35 F by circulating through the chiller with an aquarium pump. This is pump loop number 1. As AJ mentioned above ... This creates stored cooling capacity which is needed because 1/10 hp is only about 1200 BTU/HR.

My experience ... Temperature of 11 gallons in the fermenter is around 80 to 85 F. Fermenter has cools inside it (SS Brewtech). I set my temp controller to 64 for ales. Smaller pump (pump loop 2) circulate the cold water in the cooler through the coils in the fermenter. In 20 to 30 minutes, I'm at pitch temperature. In terms of holding fermetation or crash temps, I've had no problem keeping 22 gallons in three separate fermenters as low as 38 F

Very helpful buddy thank you!

Is this for 5 gallon batches that you are dropping to pitch temps?

 

[ajdelange]

Thanks to you friend, maybe we can work this common issue out. I did the calculations and I have the BTUs needed. What I am unclear on is how to take this number to size my storage of cold fluid.

Ostensibly the problem is pretty simple. You have V1 units of wort at T1 and V2 units of cold water at T2. If you mix them the temperature is T3 and

T3*(V1 + V2) = T1*V1 + T2*V2

from which you can work out what m2 or T2 should be in order to get a desired value for T3. Solving this for the volume at T2 required to get the wort to T3 gives:

V2 = V1*(T1 - T3)/(T3 -T2)

The problem is that if you mix them you can't unmix them so you have to get the heat from V1 to V2 without mixing them i.e. through a heat exchanger of some sort and when you do that the heat does not transfer immediately but must flow though the exchanger from one to the other. In your case you could circulate the stored cold water through the jacket (the previous poster has attemperation coils through which it is circulated) but it will take multiple passes (an infinite number in fact) before all the 'cold' is transferred. Thus you strive to get T2 as low as possible and to have as large a volume as possible available. So that is what you shoot for; the largest volume of cold water as cold as you can possibly get it.

 

[MidAtlanticBrew]

Very helpful buddy thank you!

Is this for 5 gallon batches that you are dropping to pitch temps?

11 gallons

 

[xico]

11 gallons

To follow up on all this I think we're ready to make the purchase for our system. I've been looking at models, would you mind sharing more about your setup? We would have this chilling system in the kitchen. I am doing upwards to 20 gallon batches now, what kind of pump are you using? What is your cooling system?

Thanks again. If it helps for advice my unit is a brew in a conical with a jacket for cooling. This jacket I keep clean because I also use it for my sparge heating.

 

[MidAtlanticBrew]

will posts some pics tomorrow

 

[MidAtlanticBrew]

Xico, Here is how I do it, Two of three fermenters shown. Edwort's Apelwein in the 5 gallon, a pale ale with centennial, cascade and citra in the 14 gallon . I have the cooling coils and temp control system for each fermentor. Other components include a 30 gallon cooler, and an aquarium pump and a 1/10 HP aquarium cooler. This is a corner of my kitchen, a some point I'm going to need to make the make the cooler look like a piece of furnature. also a good idea to secure the cooler drain to prevent a kitchen mishap.

This is the inside of the cooler, the large pump is an aquarium pump. It circulates the water from the cooler through the aquarium chiller and back into the cooler. This pump runs all the time

The 3 smaller pumps circulate water to the fermentors. They run only on demand from the controllers. All lines are drilled through the top side wall. Including the electric line to the pumps. The only exception is the large pump which I drilled through the junction of the lid to prevent an oversized hole due to threading the plug. IMPORTANT .... MAKE SURE OUTLETS ARE GFCI. It's just $15 to prevent serious injury or worse.

Here is the Aquarium pump I use. Ideally, I set this about 6 to 8 degrees below my desired fementation temp. This minimizes undershoot when my femermentor pumps kick on. When I have a cold crash (or lager) and an ale fementation going simultaneous I obvoiusly can't maintain that so I might undershoot the fermenter set point by 1 to 1.5 degrees on every pump cycle. Not a big deal but I try to avoid it, because I'm kinda a perfectionist A lot of condensation is created during cold crash if you don't insulate the lines to and from the chiller, Note the spare fermenter lines draped over it here. I'm careful to make sure the unconnected lines don't siphon the cooler. Had that happen once but caught it early, after just about 2 quarts.

 

[xico]

This helps a lot! Thanks for sharing, I have been comparing a setup you have to using a 3.0 cu ft. chest freezer and a large reservoire and a temp controller. Pricing wise favors the freezer but when we relocate in a year the chiller and cooler is actually mobile and can come with us. How loud is the unit? How often is it running?

Great system!

 

[MidAtlanticBrew]

Thanks, the Chiller on time depends on what I'm doing. It runs the most during cold crash, second most often maintaining cold crash water with 40 F water in the cooler in a 72 F room. I'd estimate a 10 minute cycle every 2 to 3 hours during fermentaion, 100 percent during cold crash, then the 10 minutes per hour mantaining cold crashing temps. These are just estimates, you've inspired my to put a meter on it.

My unit is pretty quiet, on the order of a modern refrigerator. I bought a quiet chiller, based on reviews from the aquarium crowd. Some are noisier I suppose.

My biggest noise problem was with the pump in the cooler. The pump is quiet but the cooler cavity amplifies/resonates the vibrations. The towel resolves 90 percent of that. To give you a qualitative measure, I watch TV 15 feet from this set-up and it doesn't bother me. In terms of energy usage, the chiller is the only thing that draws significant current. It's about 75 to 100 watts. So costs are really low (I pay $.13 per KWH)

 

[xico]

After conferring with my sweetheart and brewmate, we decided to spring for a 7 cu. foot chest freezer we found in town for 150 bucks. It can hold one 14 gallon and one sanke reservoirs/fermenters and we already had a brewpi on the way as a controller which we can hook up. Both can be filled with water the day before brew day and be chilled to 32 F.

Here's the hope:

First 5ish gallons out our tap gets the temp to about 95F. This comes out and is used as caustic since it is warm. Then we plumb in the reservoirs to crash the temp from there. If we are going to ferment in the kettle (brew in a conical) we are done, if not, we can empty the sanke for chilling and then pump the wort into the sanke for pitching. If we ferment in the conical we can use the 14 gallon reservoir for cooling.

I'm thinking a single pump connected to the controller with a one-way valve fitting on the outflow to ensure the liquid line in the jacket is maintained and the pump stays primed.

I love your setup and the misses doesn't mind our brewery in the kitchen but she drew the line at an aquarium chiller and coolers laying around. Foiled by the aesthetics general..

 

[MidAtlanticBrew]

.. seems like a great path forward .... brew on!

 

[xico]

.. seems like a great path forward .... brew on!

Thanks for sharing!! I love to learn the many right ways to do things!

 

[brick_haus]

My solution to this problem is a 1/10 hp JBJ Arctic aquarium chiller with a 30 gallon cooler. I prechill ~20 gallons of water to 35 F by circulating through the chiller with an aquarium pump. This is pump loop number 1. As AJ mentioned above ... This creates stored cooling capacity which is needed because 1/10 hp is only about 1200 BTU/HR.

My experience ... Temperature of 11 gallons in the fermenter is around 80 to 85 F. Fermenter has cools inside it (SS Brewtech). I set my temp controller to 64 for ales. Smaller pump (pump loop 2) circulate the cold water in the cooler through the coils in the fermenter. In 20 to 30 minutes, I'm at pitch temperature. In terms of holding fermetation or crash temps, I've had no problem keeping 22 gallons in three separate fermenters as low as 38 F

How low can you set the controller on the JBJ chiller?

 

[MidAtlanticBrew]

You can set it for 32 F but that makes me nervous about a freeze. I stay at 34 F as my coldest temp now but I've had it down to 32 and thought I heard my pump starting to strain. Maybe I just imagined it but not taking any chances. I guess I could use a glycol solution but haven't seen a need.

 

[xico]

With beer I don't mind 32 at all. I've yet to have a freeze, but in terms of water in lines or around an impeller of a pump I agree these should be protected. I am about to build out my chilling system finally and will have to decide how to handle this. I am considering putting the ETC probe inline with the chilling system as a protective measure and work the temp down.

I'll add my setup should it help others.

 

[drksky]

You can set it for 32 F but that makes me nervous about a freeze. I stay at 34 F as my coldest temp now but I've had it down to 32 and thought I heard my pump starting to strain. Maybe I just imagined it but not taking any chances. I guess I could use a glycol solution but haven't seen a need.

Glycol or salt.

 

[ajdelange]

I'd stay away from salt as it is pretty corrosive. Popylene glycol seems ideal as it is not corrosive nor is it poisonous in case of cross contamination.

 

[helibrewer]

This will cost you more upfront but it is the unit SS Brewtech customized....it will provide all the capacity will ever need and the size is really nice:

Chiller