Temp Control Glycol Chiller

[Morrey]

I ordered a Penguin Glycol Chiller as I see many other HBT members have done the same. My question is more generic and asking about glycol temps in general.

I have two 7 gallon FTSs conical fermenters and planning to purchase a third soon. With this many fermenters running at once, I will have temp demands all over the place. A typical scenario: One conical fermenting an ale at 65F, one fermenting a lager at 50F and one cold crashing a beer at 35F.

With this scenario in mind, I'll need to run the chiller glycol temps low enough to satisfy the demand of the coolest beer or the one at 35F. With the proper mix, I can go down as low as -5F, but my question is what temp would I need to run the glycol to meet the needs of my situation?

If the glycol temp is below 32F, would the sub-freezing glycol create icing on the coils in the fermenters of the beers at 65F or 50F? Just trying to think thru this before the chiller arrives and I do a test run.

 

[Dcpcooks]

You can run it with 30% glycol and 70% distilled water. Duda diesel sells the glycol. I'd suggest you start it at 26 degrees. You shouldn't have any ice build up.

 

[dunnry]

There are two ways of controlling this, but both ways you use the chiller set to low temps (eg. 28F). You should not be concerned over icing the coils in general. You are looking to cool quickly, which is best done when the delta between chiller temp and beer temp is greatest. It is how long the glycol solution circulates in the coils that will determine how low the conical temps will go. During circulation and until a touch below freezing, beer won't start to ice up (nor the coils). So, if you are maintaining a 68F fermentation, recirculating the chilled glycol will simply transfer 68F heat into the coil and then into the glycol (with variance for efficiency of transfer material, and other factors). It will only be on for a short time and the coil will continually heat up while the chiller brings the glycol solution back down and pumps it through again. As you see, you won't freeze the coils because you are in effect, heating them and the return temp will be much warmer than the inlet temp. When you stop circulating, the coils will quickly heat to the temp of the beer (as will the glycol in the coils).

As to control, you have two options:

1. Drop a separate pump (e.g. FTS mini pump) for each conical into the reservoir and hook them each up to different temp controllers. This is an independent heat loop and is easy to understand. Each temp controller will only kick on the pump to recirculate the chilled glycol solution until the controller stops the pump based on beer temp.

2. Create a single cooling loop that continually circulates a cold glycol loop. Get a control valve for each conical the opens off the main cooling loop and you control that with a servo connected to your temp controller. This is what pro breweries do and it's a touch more complicated IMO. The valve joins the conical into the main cooling loop when cooling is required and then closes when temp is at setpoint. There is a nice paper somewhere that describes this and the order of return flow if you are interested. Perhaps someone will chime in with a link.

If you already have the FTS coils and pumps, I would choose #1 for now. #2 is overkill for just 2 conicals.

 

[Morrey]

Great, I'll set the chiller between 26-28F. The coil I figure would be in the most danger of icing would be the 35F cold crash fermenter (if I am thinking correctly) since this beer has very little warmth to offer back. I'll just have to see how it goes during my "shakedown" tests with H2O in the fermenter. The only variable missing here is fermented beer with an ABV content would have a slightly lower freezing point especially in the 35F cold crash fermenter. Should be ok I predict.

I have FTSs cooling only systems. When I hit the shoulder seasons when I may need mild warming at night, I'll shift over to my Inkbirds and heat belts while still running glycol. I ordered the adaptor plugs you suggested that allow me to use the FTSs DC pumps and plug the power supply into the Inkbird. Got a gallon of food grade glycol so I think I am ready for some testing when the chiller arrives tomorrow.

 

[Dcpcooks]

You may see freezing with h20. You'll likely not see any freezing with beer. I lager in mine and it's relatively bullet proof.

 

[Morrey]

You may see freezing with h20. You'll likely not see any freezing with beer. I lager in mine and it's relatively bullet proof.

I figured the alcohol content in the beer would give me a bit of latitude to prevent freezing unlike h2O. At least I can get a feel for the operation and check to make sure all is functioning before I have a batch of beer to deal with and find I have a glitch. All good....thanks!!

 

[augiedoggy]

I use #2 as dunnry pointed out but for more conicals... I also found that 30 degrees works well for me when lagering. I even now have my brucontrol software control the temp of the chiller so I can raise it to 33 when im not lagering . The reason for this is the chiller runs more often just to maintain the lower temps and if not needed its really a waste IMHO.

 

[augiedoggy]

There are two ways of controlling this, but both ways you use the chiller set to low temps (eg. 28F). You should not be concerned over icing the coils in general. You are looking to cool quickly, which is best done when the delta between chiller temp and beer temp is greatest. It is how long the glycol solution circulates in the coils that will determine how low the conical temps will go. During circulation and until a touch below freezing, beer won't start to ice up (nor the coils). So, if you are maintaining a 68F fermentation, recirculating the chilled glycol will simply transfer 68F heat into the coil and then into the glycol (with variance for efficiency of transfer material, and other factors). It will only be on for a short time and the coil will continually heat up while the chiller brings the glycol solution back down and pumps it through again. As you see, you won't freeze the coils because you are in effect, heating them and the return temp will be much warmer than the inlet temp. When you stop circulating, the coils will quickly heat to the temp of the beer (as will the glycol in the coils).

As to control, you have two options:

1. Drop a separate pump (e.g. FTS mini pump) for each conical into the reservoir and hook them each up to different temp controllers. This is an independent heat loop and is easy to understand. Each temp controller will only kick on the pump to recirculate the chilled glycol solution until the controller stops the pump based on beer temp.

2. Create a single cooling loop that continually circulates a cold glycol loop. Get a control valve for each conical the opens off the main cooling loop and you control that with a servo connected to your temp controller. This is what pro breweries do and it's a touch more complicated IMO. The valve joins the conical into the main cooling loop when cooling is required and then closes when temp is at setpoint. There is a nice paper somewhere that describes this and the order of return flow if you are interested. Perhaps someone will chime in with a link.

If you already have the FTS coils and pumps, I would choose #1 for now. #2 is overkill for just 2 conicals.

heres that link which I got from here as well and used...

I used these simple valves and almost 3 years later it still works great. http://www.ebay.com/itm/Electric-So...467278?hash=item3a9efcbf0e:g:wOAAAOSwyZ5Ul3s9

View attachment GLYCOLGUIDE.pdf

 

[Morrey]

I use #2 as dunnry pointed out but for more conicals... I also found that 30 degrees works well for me when lagering. I even now have my brucontrol software control the temp of the chiller so I can raise it to 33 when im not lagering . The reason for this is the chiller runs more often just to maintain the lower temps and if not needed its really a waste IMHO.

Mongoose33 and I were just talking about this as in your example. If I was running one fermenter at 65F, we wondered if it would be necessary to maintain the glycol at a low temp such as 28F? The higher I set the chiller, the more energy it costs to keep it at a high set temp. The drawback is a longer time for the pump to run cooling the fermenter. I think there is a balance here just as you are point out.

If/when I expand my system to larger capacity or add more fermenters (currently have 2 FTSs 7G fermenters), I will be looking to upgrade my configuration as you show can be done. Currently I have two controllers and two pumps so each fermenter is functioning on its own independently. I am equating the single supply system (#2) to my irrigation system where I have a main trunk supply line with multiple solenoids that control each valve and then each zone may be provided water flow. Not exactly the same but the way I am visualizing the system w/o the return loop of course.

**Thank you for the glycol guide PDF. I printed it off as a reference. Very valuable information.

 

[Dcpcooks]

I have a heated and chilled recirculating water bath that I use for temp control. It's basically a sous vide heater in a stainless vessel that has a refrigerated chill plate on the bottom or the glycol reserve.

The reason I reference this is i usually set the units temp control just below my target temp for chilled fermentation. Or above for heated fermentation. So I'll set it at 64 and my beer will be a degree higher than my set point. So you don't need to be at 28 to keep a batch at 64.

The only issue I see is your chiller is designed to run at lower temps. So I'm not sure how warm you can operate it. That's a question for the manufacturer.

 

[dunnry]

Mongoose33 and I were just talking about this as in your example. If I was running one fermenter at 65F, we wondered if it would be necessary to maintain the glycol at a low temp such as 28F? The higher I set the chiller, the more energy it costs to keep it at a high set temp. The drawback is a longer time for the pump to run cooling the fermenter. I think there is a balance here just as you are point out.

If/when I expand my system to larger capacity or add more fermenters (currently have 2 FTSs 7G fermenters), I will be looking to upgrade my configuration as you show can be done. Currently I have two controllers and two pumps so each fermenter is functioning on its own independently. I am equating the single supply system (#2) to my irrigation system where I have a main trunk supply line with multiple solenoids that control each valve and then each zone may be provided water flow. Not exactly the same but the way I am visualizing the system w/o the return loop of course.

**Thank you for the glycol guide PDF. I printed it off as a reference. Very valuable information.

I would definitely not keep my glycol chiller at a warmer temp. It should be in the 26-30F range. The vast differential is very valuable for chilling quickly and is pretty much the point of a glycol chiller.

If your concern is that keeping the solution at 28F vs 65F will take more energy, the answer is yes, undoubtedly so. However, you won't be able to tell how much energy this consumes in comparison until you try it. Once a chiller is at temp, it is the frequency with which it cycles the compressor which takes the energy. That is a measure of the efficiency of the chiller to insulate and maintain a temp as well as how often you use it and return warm glycol. I don't have a glycol chiller, so someone else will have to answer how efficient they are at maintaining temp once cold. Buy a Kill-a-Watt and measure the difference yourself! I would bet it's pretty close overall.

 

[trapae]

Morrey, how do you like your new glycol chiller? I’m thinking of purchasing this one for the same reason. Is it working out well for you? I have a couple conical’s. The penguin is cheaper than the SS brewtech glycol chiller but looks bigger. Any pros and cons so far?

 

[Morrey]

Morrey, how do you like your new glycol chiller? I’m thinking of purchasing this one for the same reason. Is it working out well for you? I have a couple conical’s. The penguin is cheaper than the SS brewtech glycol chiller but looks bigger. Any pros and cons so far?

I'm very happy with the Penguin. It does all I could want a chiller to do with plenty of cooling ability. I have never seen an Ss Glycol Chiller in person, so its hard for me to say much about them....but the Penguin served me well all summer in sweltering temps. I have 100% confidence in recommending one for your brewery.

 

[trapae]

Cool. So you don’t have any problems cold crashing into the 30s? Or running multiple fermenters at once?

 

[Morrey]

Cool. So you don’t have any problems cold crashing into the 30s? Or running multiple fermenters at once?

I have three fermenters currently on my chiller. The biggest restriction is not with the ability to cool, but with the ability to fit all the pumps down into the glycol reservoir. Three FTSs pumps pretty well fits with little or no room to spare.

I generally run 33:67 glycol to water at 28F. I'll crash to 35F, but don't leave it there very long as all I am doing is dropping out the solids before moving to keg and then to the lager chamber. In other words I not using the fermenter and chiller to cold store beer.

 

[augiedoggy]

I have three fermenters currently on my chiller. The biggest restriction is not with the ability to cool, but with the ability to fit all the pumps down into the glycol reservoir. Three FTSs pumps pretty well fits with little or no room to spare.

I generally run 33:67 glycol to water at 28F. I'll crash to 35F, but don't leave it there very long as all I am doing is dropping out the solids before moving to keg and then to the lager chamber. In other words I not using the fermenter and chiller to cold store beer.

this can easily be remedied if you want to use more conicals by going with a single pump and valves... most chillers do have a powerful pump included in them to accomplish this. it does require more relays.

 

[sensei247]

I use #2 as dunnry pointed out but for more conicals... I also found that 30 degrees works well for me when lagering. I even now have my brucontrol software control the temp of the chiller so I can raise it to 33 when im not lagering . The reason for this is the chiller runs more often just to maintain the lower temps and if not needed its really a waste IMHO.

Do you have a penguin chiller which is integrated with Brucontrol? Looking to do this...

 

[augiedoggy]

Do you have a penguin chiller which is integrated with Brucontrol? Looking to do this...

I have a couple a regular chillers I did this with at both home and the brewery.. I use brucontrol to control the thermostat in one of them and I have them both setup to use the chillers built in pump but you could easily control any pump or pumps with it. I see no reason it wouldnt work with a Penguin unit. my chiller at home only has a 3 gallon sump.

 

[sensei247]

I have a couple a regular chillers I did this with at both home and the brewery.. I use brucontrol to control the thermostat in one of them and I have them both setup to use the chillers built in pump but you could easily control any pump or pumps with it. I see no reason it wouldnt work with a Penguin unit. my chiller at home only has a 3 gallon sump.

Thanks for that. Do your other chillers have PID thermostats like the ones on the Penguin systems? Eg basic thermostat with digital readout. I’m thinking I may be able to open this up and tie in the thermostat line to the BC interface

 

[augiedoggy]

Thanks for that. Do your other chillers have PID thermostats like the ones on the Penguin systems? Eg basic thermostat with digital readout. I’m thinking I may be able to open this up and tie in the thermostat line to the BC interface

They did run on stc1000 type hysterisis controllers and yes its easy to swap out the BC relay and temp probe to take over temp control.

 

[sensei247]

They did run on stc1000 type hysterisis controllers and yes its easy to swap out the BC relay and temp probe to take over temp control.

Super helpful. Any wiring diagrams and/or pics you can share?

 

[augiedoggy]

Super helpful. Any wiring diagrams and/or pics you can share?

sadly I have none, I will take some photos for you though. every chiller is a bit different.