Wort Chiller Efficiency

[Walrus_Walrus]

This is basically a post to help others that may run into the same issue I am/was to reduce wort/mash chilling time to be able to pitch yeast as quickly as possible (avoiding unwanted bacteria doing mysterious things to fermentation, and to save time of course!). I am using a large industrial strip warehouse space to mess with my drink making effort. There are some industrial work applications and some fields very close by. Seems harmless, but what if someone is using a tractor to mow the field while I have my garage bay open, and I am trying to cool my mash... see where I am going with this?

I have two 100 quart pots to heat various mash bills. I generally like to run 15 or so gallons in each, simultaneously. It gives room to stir and not make a giant mess everywhere. When it comes time to cool the mash down, I park a giant blue industrial trash can filled with water between the mash vessels and run a submersible pump to feed a herms coil in each mash vessel. This is not very efficient because the water returning from the herms coil heats up the main water source too fast, and the cooling process takes SEVERAL hours to be enough to pitch yeast without roasting it. I don't have much of a way to continuously cool the source water to counteract the heat soak... I am also in a region that will become quite hot during the summer, which won't help either. I need something that I can set and not have to monitor so much. Something that doesn't need a lot of attention while it's doing its thing.

So here comes the experiment... I just ordered a 12" air mover and a 14" x 14", 3 row heat exchanger (just ordered and they are still being shipped). I will essentially use the same water source and pump, but feed into the heat exchanger, and then the "chilled" water will feed into the herms coils. Then this will circle back to the water source to complete the cycle. I am hoping that the heat exchanger will be efficient enough to chill the water, cool the mash faster, and reduce or eliminate the heat soak in the source water container.

Once I assemble this I can report some findings and let you know how it works with some readings, times, etc.

[pfshine]

A fan and radiator works great for this.

[Sungy]

I would try taking the water from the tank directly into your herms coil then cool it with your heat exchanger and return it to your tank. The reason for this is the heat exchanger coil will perform better with a larger temperature differential between air and fluid being cooled.

eg. air at 75 deg and fluid at 80 deg = differential of 5 deg.
air at 75 deg and fluid at 140 deg = differential of 65 deg.
I can not estimate final fluid temp as that is affected by air flow across heat exchanger and fluid GPH.

edit : Lower GPM increases contact time between fluid and air and increases efficiency in the air heat exchanger but will also increase the contact time of the mash herms cooler resulting in warmer discharge temperature from mash cooler and increased differential between air and cooling water.

[bitter]

Depending on the mash say you doing a single malt off the gain... you could also use a counter-flow chiller to get the final temp drop to pitching when going to the fermenters, but this will not work for mashes you aren't sparging etc to remove the grains.

One the guys I know is big into beer made a pic controlled counterflow chiller. It uses input temp and output temp to control a value that increases/decrease water to get a specific temp drop. Works really well. He had a program also to minimize water usage for when there was a shortage. Typically it would be a full brew day and do brews back to back so the preheated water would be used to start the next batch. Most I heard of him doing was 4 batches in 1 day, last cooling water was used in the washing machine to do a washing.

B

[Walrus_Walrus]

Sungy: I hear what you're saying and can try it both ways (heat exchanger on one side or the other of the coil) just to see what happens. I can replace actual mash with boiled water just to visualize.

Bitter: I haven't been sparging these mash bills, so I may have to find something else. I see what you are saying though. I may experiment with ways to get the same volume/ABV in my ferment while doing a sparge if this is a more effective method. I could still keep it mechanical and run the liquid through the heat exchanger/fan combo... I'll just have to try a bunch of different methods to see what works best with the equipment I have and my goal and objective for the stills.

When I get the equipment in the mail and build the system out to run it, I can take pictures and post them here with stats and everything so we can look at the outcome. Thanks for the input guys!

[bitter]

Good luck! Look forward to seeing your results.

B

[Walrus_Walrus]

I got the fan in. Still waiting for the heat exchanger.

Fan specs:
Utility blower, 3/8 HP, 2905 CFM, 12" round
http://www.northerntool.com/shop/tools/ ... _200007174" onclick="window.open(this.href);return false;" rel="nofollow

I conveniently acquired this and had a large water spill in my shop mere minutes later. I couldn't help but to put this thing to use for what it was originally intended to do. This little thing is kinda loud but serves quite well... probably going to be overkill for the 14" x 14" x 3.5" heat exchanger...