Need Help Getting Chiller Running Right

[ibrewforyou]

i need some pointers on getting my rooftop glycol chiller working properly. i just took over a brewing job and don't know much about this piece of equipment.

first of all i am having trouble getting my beers down to 32/33F (the lowest i can get it down is 36F). its a G+D chiller, refrigeration was serviced on it so no leaks there. solenoid is working fine on the fermenter.

i figure a good place to start is to check the glycol:water ratio? whats the best way to do that?
i have a temperature controller on it that has a setpoint and a differential on it. i have no idea what to set them at! it was set at 27F w/ a differential of 4. i lowered the setpoint down to 25 but moved it back up after most the lines in and out of the pump and evaporator frosted up (bad?)

could someone point me in the right direction to start and figure things out?
thanks

[jimvgjr]

Hi there,

Does the chiller system reach the 27 F setpoint and compressor shut off, or does the compressor keep running and the unit not reach setpoint? How quickly does the fermenter pull down to 36 F? The closer you get to your glycol temperature, the harder it is going to be cool. 32 F seems pretty low for a desired pull down temperature.

A safe glycol percentage is 33% glycol to 67% Water, giving you a freeze point around 0 to +5 F, you want the freeze point to be 20 to 25 F below your chiller system setpoint. This thread on this site has a few different methods for testing the concentration.

Frost on the pipes is normal, a big accumulation of ice is not good. One of the biggest issues that we receive technical support calls for are the result of lack of glycol in the system- I think you are correct to say this is the best place to start.

Once you have confirmed there is a correct percentage of glycol, I would look at a possible flow issue through your fermenter jacket. You could have air trapped in the jacket, improper pump rotation (check Chiller Manual or call mfg to confirm this), or a piping issue that could be causing this.

Hope this helps, good luck with your new job.


Best Regards,

Jim

Pro Refrigeration Inc.
www.prochiller.com

[beerking1]

Jim,

I am getting a system up and running. I am hearing a gurgling inside my BT (when it is empty) when I run the Glycol. could this be air in the jacket? If so, what can I do about it?

Thanks,
Lyle

[brewman21]

Beerking, you need to put a automatic vent valve in your gylcol loop. It should be put on BT at its highest point of return to your glycol loop. You can buy them at http://www.grainger.com/Grainger/wwg/search.shtml?searchQuery=automatic+vent+valve&op=s earch&sst=All&Ntt=automatic+vent+valve&N=14926. If you have3/4" copper pipe as I, you need to get a baseboard tee, its a 90 degree elbow with threads for vent to screw into, also available at grainger. Hope this helps. CHEERS!!

[jimvgjr]

What brewman21 said

Air vents are the best way to bleed the air from the system.

Good luck!

Jim

[emergent7]

I think I'm having a similar problem regarding air in the glycol system. I have to release air pressure from the system every time I want to use the heat exchanger, otherwise glycol won't even flow through it- I'll just get water going through it. Thanks for the tip on the automatic vent, I"ll be sure to look into it.