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bvelt
03-10-2008, 10:20 PM
We have a 7BBL CDC system with (4) 7BBL cone bottom fermenters. The glycol jackets are the banded version (think a bumble bee) and cover no more than 60% of the tank. The run from our current glycol unit to our tanks is around 40 feet of 1/2 inch pvc and copper piping. We've just brewed our first two batches and can tell the system we purchased is very undersized. It takes days to crash one tank with the other tank simply maintaining 70 degrees. I need advice on what size system would work for us. I'm sure there's more info you require from me to give any recommendations so I've included my phone number below. Any help would be much appreciated as I trust this website much more than a plumber or refrigerator repairman who would try to sell me the most expensive chiller possible.

-Brad Veltman
Aspen Brewing Co.
970-920-2739

GOOSE
03-11-2008, 07:46 AM
What are you running the glycol at? Lowering that temp will help big time, even if the system is too small it will help for now.

Hang in there

GOOSE

lhall
03-11-2008, 07:52 AM
Hmm- 1/2" pipe is going to cause a lot of restriction. What size chiller is it (hp)? WHat temp are you running? What supply pressure?

youngbuckbrewer
03-11-2008, 08:52 AM
1/2" pipe seems really too small for a feed in pipe. We did ours with 1 1/2" feed pipe and then at each tank inlet teed off and reduced to 3/4" for the thread fittings into the tank jackets. It required a little bit more volume of glycol to fill the bigger pipes but it also helps with keeping up with your tanks demands.

You should also lower the temperature of your glycol chiller to atleast 5 degrees below your lowest crash cooling point. The glycol temp will raise a degree or two on it's way to your jackets. Also it is always best (if you can afford to)to buy a chiller that is slightly oversized for your system so that you can expand or so that the chiller doesn't have to be constantly running.

You might also want to check your mixture of glycol. It should be aournd 50/50 H20 and glycol. Good luck. Good to see abrewery back in Aspen!!:p

beertje46
03-11-2008, 09:20 AM
You might also want to check your mixture of glycol. It should be aournd 50/50 H20 and glycol. Good luck. Good to see abrewery back in Aspen!!:p

a 50/50 mix gives you protection down to -31F. and is an inefficient mix. You should shoot for around 38% glycol by volume. This gives protection to -2.4, well more than good. The Brix on a 38% mix should be 28 degree if you want to do a quick check.

Check out: Pro Refridgeration (http://www.prochiller.com/reSalesLit.html) for some snazzy stuff like the Brewery Glycol Guide and Brewery Refrigeration 101.

bvelt
03-11-2008, 09:47 AM
Sorry, to correct my first posting, the piping is 3/4". As for the other questions, we are running the glycol at a high of 15 degrees and low of -10 degrees. The chiller is a 1HP unit. The pressure is a high of 440 and low of 162. I got all this info off the unit itself. It's a Banner Powerpack model number 60813.

SPECS
13.2 amps
115 volts
60 hrtz single phase
max circuit 23

We're going to try to make some insulated jackets today because it looks like a lot of the cold is escaping through the outside of the jackets. Hopefully this will help but I still get the feeling the system is undersized to be maintaining a couple tanks and crashing a couple at the same time.

bvelt
03-11-2008, 09:49 AM
Here's a few more photos of the glycol unit...

-Brad

lhall
03-11-2008, 10:47 AM
I've only seen Banner power packs used as part of a gylcol-cooled draft system. I don't think that 1 HP is going to do it.

GlacierBrewing
03-11-2008, 11:08 AM
a 50/50 mix gives you protection down to -31F. and is an inefficient mix. You should shoot for around 38% glycol by volume. This gives protection to -2.4, well more than good. The Brix on a 38% mix should be 28 degree if you want to do a quick check.

Check out: Pro Refridgeration (http://www.prochiller.com/reSalesLit.html) for some snazzy stuff like the Brewery Glycol Guide and Brewery Refrigeration 101.

Hi Brad,
I second David's comments. We were having similar issues with cooling vessels under increasing demands in the summer. I reduced the freeze point of my glycol reservoir by adding more glycol to the mix. I run my glycol around a freeze point of 4.2 degrees F. (You can get a glycol refractometer to check your concentration from a lab supply store like Cynmar.) This allows me to set the system temperature (of my glycol reservoir) to 27 degrees F. I can then crash a 10bbl tank (or several tanks) from 65-70 F to 30 F overnight while maintaining lagering tanks at 30 F. Remember to not set your tank temperature too low, your beer can freeze. Also, I insulated all my glycol piping. I'm convinced this help to increase the cooling ability of our system, especially in the warmer months.
The helpful folks at Pro Refrigeration are a wonderful resource for trouble shooting glycol systems. I suggest you give them a call.
I'll be in your neck of the woods this weekend and next week. I look forward to seeing your operation.
Prost!
Dave

GlacierBrewing
03-11-2008, 11:21 AM
Some more thoughts....
Brad, what size pump are you using to distribute the glycol from the reservoir to your tank farm? How are you isolating the individual tanks and their cooling zones: tank-mounted solenoids, tank-individual pumps, other? Do you know that the line pressures of your glycol-feeding piping are right after the feed pump and at the furthest point from the pump?
Dave

beertje46
03-11-2008, 11:35 AM
I've only seen Banner power packs used as part of a gylcol-cooled draft system. I don't think that 1 HP is going to do it.
That's what it is. According to Banner's website this unit is good for cooling 600'+- of already cold draft beer. The 1 hp size is compounded by the small reservoir. There is a local two bbl. brewery that uses three of those units to cool four 2bbl. unitanks.

jimvgjr
03-11-2008, 12:18 PM
I think you are on the right track. I did a quick load calculation and based on 2 EA 7.5 Bbl Fermenters in active Fermentation, 1 EA in pull down, and 1 EA holding at 32 F. Came up with 6,000 to 8,000 BTU/HR- but this didn't factor non-insulated vessels which depending on room temperature could easily double this load.

CHILLER CAPACITY
A typical 1 HP Unit (based on the pictures you posted) will provide a cooling capacity in the 6000 BTU/HR range (based on R22, an evaporator Temperature of 15 F and a 90 F Ambient). If you contacted me for a bid for your application, I think I'd suggest a 3 HP Chiller System.

FLOW
As a rule of thumb, I like to size the glycol pump and piping for 3-5 GPM per jacket. So with 4 vessels I would estimate a flow requirement of 12-20 GPM. I would use 3/4" piping for flows no more than 5-8 GPM range. Upsizing of the glycol lines should definitely help.

INSULATION
Great idea to get these Fermenters wrapped, as well as the piping.

Shoot me an email or give me a call with any questions, would be happy to help.

Good Luck,

Jim

Jim VanderGiessen Jr
TEL 253.735.9477 Extension 203
TOLL FREE 800.845.7781
FAX 253.735.2631
jimvgjr@prorefrigeration.com
www.prochiller.com

youngbuckbrewer
03-11-2008, 02:09 PM
You have to be sure that your glycol is mixed at an even ratio so that you are protected from freezing if your chiller is located outside of the building. In Montana we have frequent temperatures in the below zero ranges and we mix our glycol to withstand that (50/50 mix). There are days when our glycol chiller compressor will not run all day because it is colder outside than the coolant is set for and the feed pump will run all day with coolant. In Aspen you may have similar conditions in the wintertime. If your chiller is inside your building than you have different parameters and can mix your glycol with more water than 50/50.


Michael Uhrich

youngbuckbrewer
03-11-2008, 02:09 PM
You have to be sure that your glycol is mixed at an even ratio so that you are protected from freezing if your chiller is located outside of the building. In Montana we have frequent temperatures in the below zero ranges and we mix our glycol to withstand that (50/50 mix). There are days when our glycol chiller compressor will not run all day because it is colder outside than the coolant is set for and the feed pump will run all day with coolant. In Aspen you may have similar conditions in the wintertime. If your chiller is inside your building than you have different parameters and can mix your glycol with more water than 50/50.


Michael Uhrich
Owner/Brewer
Carter's Brewing
Billings, Montana

liammckenna
03-11-2008, 06:11 PM
I cannot but echo the query regarding the 1 hp chiller. Is it undersized?

A 50/50 glycol mixture of PG and water should yield about -24-25oC in the chiller without freezing BUT remember that in a cooling system the glycol is the heat transfer medium in your jacket but the water is the heat holding medium. Water has a huge heat capacity. Glycol does not.

In other words, for maximum energy efficiency of your cooling system, you want to minimize the amount of glycol necessary to achieve the temperatures you're after.

Here's a link for freezing points of glycol mixtures.

http://www.ketemalp.com/pdfs/glycol_freezing_point_table.pdf

Good luck.

Pax.

Liam