Brewhemoth glycol chiller test

For chilling on my Brewhemoth I am using their stainless immersion chiller. They 'stretched' the coils out at the factory for me like has been done by people on several other posts.

I have about 3 gallons of glycol in a tub in my freezer with a submersible aquarium pump (780 GPH). My first cheap harbor freight pump would not even move the liquid. The new one trickles out the return, but provides enough flow.
The freezer is set to max and gets the glycol down to about -20 degrees. I discovered that regular vinyl tubing gets way to brittle at that temperature and cracks creating a mess of glycol. Silicone tubing remains flexible. I am using a love controller to turn the pump on and off as needed.

Without insulation in a room that is 68-70 degrees I can maintain a temperature of 49-50. With a sleeping bag draped over the fermenter I got it down to 43 degrees. One problem I am seeing is that the pump is heating up the glycol faster than the freezer can chill it.

The next step is to insulate the fermenter. I'd like something that can easily be removed for cleaning and using heat wrap. What are people using to insulate theirs?

do you have pics of your immersion coil spread out ?

So the freezer uses air to cool the glycol I guess? Just a thought, why not remove the evaporator from the freezer, and directly immerse the evaporator in the glycol? The direct contact would probably be much more efficient (and faster) than using air to liquid cooling.

MC

How about removing the pump from the bucket of glycol? I know a bunch of aquarium pumps can be used outside of the tanks. It would add an extra hose going from your glycol bucket to the pump, but that would keep the heat from the pump from warming up you glycol.

gregkeller said:

How about removing the pump from the bucket of glycol? I know a bunch of aquarium pumps can be used outside of the tanks. It would add an extra hose going from your glycol bucket to the pump, but that would keep the heat from the pump from warming up you glycol.

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wouldn't the pump then warm the freezer from the heat its producing then the freezer would be running none stop to combat the heat from the pump.

Good suggestions. I don't want to tear apart my freezer though, since I use it for hop storage too.
The pump is a submersible pump so it needs to be in the glycol. I may look for a different pump that could be mounted outside of the freezer.
I think with some good insulation I can get to lagering temps now, just have to figure out the best material that can come off easily too.

I'll post a picture of the stretched chiller this evening.

I used a mix of 2gal glycol to 2gal RO water. It won't freeze at that ratio at -20degF. My chiller coil isn't stretched... might have to go with that technique to avoid thermal stratification. That's been a big problem for me with this setup. The other is the massive amount of condensation I get when chilling to lager fermentation temps. Water drips down all over the valves and grows mildew in short order... not what I want on my nice clean butterfly valves!

I tried the sleeping bag method. It does help with the stratification, and of course the pump does run less often. Still drips condensation, and I end up with a soggy sleeping bag. BTW, with 65degF ambient, and no insulation, the chilling system holds 50degF at the bottom of the fermenter, with the glycol bath hovering around -5degF. BTW my cheapo chest freezer runs at about 100w about a third cycle duty to keep the air inside at -20degF.

I'm thinking now that I'll enclose the entire brewhemoth in an insulated cavity (maybe 4'' of foam), ditch the internal chiller, an use a transmission cooler/fan to chill the box. This method worked quite well to chill my blichmans... that is, before I sold them and bought a hemoth. I used a cooler full of ice water in that setup. Did not enjoy swapping out 2L bottles of ice every day though.

I don't like having to clean the chilling coil separately from the fermentor, for which I use a cip ball.

StMarcos said:

I tried the sleeping bag method. It does help with the stratification, and of course the pump does run less often. Still drips condensation, and I end up with a soggy sleeping bag. BTW, with 65degF ambient, and no insulation, the chilling system holds 50degF at the bottom of the fermenter, with the glycol bath hovering around -5degF. BTW my cheapo chest freezer runs at about 100w about a third cycle duty to keep the air inside at -20degF.

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Sounds almost exactly like my results and setup. I am leaning toward insulating with some flexible foam sheets - polyethylene or neoprene that I can strap on and easily remove. The other method I am considering is a rigid foam box I can set over it. I don't think it would work as well though.

I like the internal chiller. It is easier and I think cheaper than making a "jacketed" glycol line around the outside of the fermenter with copper tubing and I sure don't want to struggle with trying to put it inside a fridge after every brew. Here is a picture of the stretched version.

I plan on having a buddy weld a 1/2 threaded nipple on the chiller lid for a CIP ball (like nostalgia's) so that I can clean and sanitize it with the fermenter.

I can at least get down to lager fermenting temps. Anyway, I'd rather do the actual lagering in kegs in the fridge.

Any small magnetic drive pump mounted outside the freezer should work and not add heat to the system since the motor is separate from the head.

The pump I use is a danner magdrive 5 or 7. Coolant barely dribbles back into the reservoir. I do think that the id of the coil could be larger.

Having the pump external to the freezer would add too many complications I think.

I thought about the foam box that you just drop on the whole thing idea too. Complicating the matter is the entrance and exit of the cooling tubes.

I'm going to try and stretch the coil, and then check to see how much difference that makes. I'm pretty sure I'll end up having some sort of chamber, as I also have a problem with heating and thermal stratification. I have a 200w heat mat stuck to the side.

Would be nice to have a glass door so I could see the stainless etc. Kinda like a peep show.

Something like this?

http://homedistiller.org/forum/viewtopic.php?f=2&t=19973

lil bigger than that

My only issue with the immersion chiller is the diameter and lack of being able to drop the beer to 38F. If I could truly cold crash the beer effectively my life/lower back would be great.

My preference is to crash fast and cold so I can get the next beer into the fermenter.

Brew on!

One thing I can say for sure, and it has already been mentioned with the sleeping bag. If there is not and air tight bond between the metal and the insulation there will be condensation. I used the nomaco kflex sheets found here: . Sticky back works like a champ. It is water proof so a wipe down is all that is needed for cleaning.

StMarcos said:

Sounds like a nice product. Only Rvalue of 4 for the 1'' stuff. What did you use? How much of the fermentor did you cover? Would love to see pics!

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Here is a product sheet, scroll down to the thickness vs temp and relative humidity. http://www.insulation.org/mtl/pdfs/001028_474.pdf Basically if the outside temp is 85 degrees whit a humidity of 70% and your tank wall is 32 degrees you need 3/4 of an inch to stop condensation. cover as much as you can where the beer is contacting the walls of the fermenter, think of a beer can cozy.

Here is a photo. It is a 37 gallon Stainless fermenter with convex bottom. The thermowell is mounted at the 9 gallon mark. I currently ferment with 17 gallons in it and 25 feet of stainless coil and with chilled water running through it is all you need for ales. I have not tried with a lager yet but on an ale the water is pumped through the coil for about 4 minutes every 5 hours during the peak of fermentation.

Maybe I'll have the GF knit one

Actually considering using this stuff on a mashtun.

There's a product called armaflex. It comes in sheets. It's used in the refrigeration world for doing what you want to do. Once you insulate the tank and with -20 F glycol flowing through the coil. The coil might ice up. Unless, the beer is high octane. The coil that the company provides has a moderate pressure drop. You may need a higher volume pump. If the pumps is direct drive, a pressure actuated bypass or at the least a ball valve would be good to install between the discharge and suction. Low temp pumps usually have different seals and are insulated. You may want to thin down the glycol, like the other brewer did. In -20 to -40 F low temp industrial chillers, it isn't recommended to run 100% glycol. Heat transfer is less using 100% glycol. A fermenter that can be pulled down to 30's F is usually jacketed. They're designed in such away that the coolant temp is very close to the desired temp of the beer. Having a close TD keeps the beer from freezing on the tank wall. A circ pump is used to keep the beer moving, to transfer its heat to the jacket and evenly cool the beer. You may want to consider using a pump to circ the beer around the tank, especially with -20 coolant temps. You might want to get rid of the box 90's and use longer radius 90s. Or, bend up soft copper into sweep 90's and fit them to the stainless. Less pressure drop. The fermenter you have is a great investment and once you work out the cooling bugs. It will be a very valuable tool in your brewing world. The spunding valve and CO2 port are great...I have two 14.5 G stainless conicals with a blow off and spunding valve. I use CO2 to transfer from primary to secondary to the keg. No more using gravity or worrying about head space, air or micro bugs getting sucked in.

Where did you get your glycol? I tried this last year with RV antifreeze and it froze solid on me. Even mixed 50-50 with Everclear it still slushed up. I guess you need 100% pure glycol with no water.

I can't remember where I got the glycol. I diluted it 50-50 with RO water, and it sits in a tub in a cheap chest freezer on the coolest setting. I don't really want to bump up the temp as I keep hops and frozen yeast in the same freezer. Never was sure if anything was freezing up on the coils in the fermenter. I sold the hemoth chiller and now cool the ambient in a big foam box, with a tranny cooler and some fans.

VladOfTrub said:

There's a product called armaflex. It comes in sheets.

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The armaflex looks exactly like what I am using, even the backing looks the same. One thing I would say abut it is that it is supposed to be used in a stationary location. It rips easy, I am going to cover mine in black duct tape to protect the insulation.

The backing on the armaflex I have used is a moisture barrier. It wasn't self sticking. It is glued on using armaflex cement. The stuff I used was for low temp chiller tanks and chiller barrels. Armaflex is usually cut with a hacksaw blade. It's pretty tough stuff. Once it's applied it's hard to tear it. Duct tape doesn't stick to armaflex very well. Whatever is in the foam turns duct tape brittle. They sell a special tape for it. The tape has the sticky backing. It falls off with time. We applied a type of paint over the insulation called hard cast to protect the rubber..... Nice job on your kettle. The density of the insulation will really hold the temp, whether cooling or heating. The duct tape will surely, help, to keep it from ripping.