Tanks not reaching 32F. Quesiton about glycol system.

[dfalken]

I am having problems getting my tanks down to 32. My tanks are 40HL and even when only one is being cooled it still won't reach 32. My glycol system is set to turn off at 24F and to turn on at 28F. The glycol is reaching the set temperatures. The ambient temp in the brewery is around 88F during the day and during the day the coldest I get the tanks is to around 40F. At night I can get down to around 36F. One possible culprit could be the length of my glycol system. My glycol reservoir is around 60 feet away from my tanks. I transport the glycol in 2 inch ABS pipes insulated with 1/2 inch nitrile foam (rubtech). It is the black soft pipe insulation. My entire lines are insulated all the way to the tank inlets (including the solenoid and hand valves). The tanks have dimple jackets in the cones and half-pipe jackets in the body. The have 3 inches of insulation.

Anyone have ideas as to why I can't reach lower temps?

[NHBrewer23]

I am having problems getting my tanks down to 32. My tanks are 40HL and even when only one is being cooled it still won't reach 32. My glycol system is set to turn off at 24F and to turn on at 28F. The glycol is reaching the set temperatures. The ambient temp in the brewery is around 88F during the day and during the day the coldest I get the tanks is to around 40F. At night I can get down to around 36F. One possible culprit could be the length of my glycol system. My glycol reservoir is around 60 feet away from my tanks. I transport the glycol in 2 inch ABS pipes insulated with 1/2 inch nitrile foam (rubtech). It is the black soft pipe insulation. My entire lines are insulated all the way to the tank inlets (including the solenoid and hand valves). The tanks have dimple jackets in the cones and half-pipe jackets in the body. The have 3 inches of insulation.

Anyone have ideas as to why I can't reach lower temps?

Do you have a thermometer located close to your tanks? You may find the glycol is warming up by the time it gets to your tanks. Also, do you have any idea as to the flow rate through the system? A slow flow rate could hinder your cooling capacity. Are you cooling tanks under primary fermentation prior to those you are trying to crash or your bright tanks? Are your bright tanks dropping down in temperature? Are your jackets completely covered in the fermenters? What size glycol line is going to the tank? I would suggest 1". Just a few questions.

[dfalken]

Do you have a thermometer located close to your tanks? You may find the glycol is warming up by the time it gets to your tanks. Also, do you have any idea as to the flow rate through the system? A slow flow rate could hinder your cooling capacity. Are you cooling tanks under primary fermentation prior to those you are trying to crash or your bright tanks? Are your bright tanks dropping down in temperature? Are your jackets completely covered in the fermenters? What size glycol line is going to the tank? I would suggest 1". Just a few questions.

Hi NHBrewery, thanks for replying to my question. You asked about a thermometer close to the lines and my quick answer was "no I don't have one" but I just realized I do, I have a thermometer on the glycol input side of the heat exchanger. I will check to see what the temp is however I do remember it starting below zero during knockout just never paid attention to exactly how much below zero (Celsius). If I find it is warming up too much then I could possibly add insulation to the lines to help correct that problem.

My brights are the first tanks being cooled. I am using first in last out and I also have a bypass valve connecting input line without output line to avoid putting too much pressure on the lines in case the pump runs and no solenoid is open. Actually that valve might be the culprit as I might have it open too wide which would be decreasing flow through the tanks. I will close it a bit further and see what happens. My pump is large enough and the flow is definitely sufficient but if the bypass valve is open too much that would obviously decrease flow through the jackets.

The jackets are completely covered in the fermenters as well as in the brites (the brites are also not reaching temp). The ABS run that comes down from the backbone into the tanks is 20mm in diameter so slightly less than 1". from that pipe I connect to the tanks through a short piece of 3/4" hose.

Thanks again for your comments, at least now I have a few things to check to attempt to trouble shoot my system.