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Chilled Water and Anti-Freeze:

Never posted here.

I have a situation where there are wine fermentation tanks. There needs to be both heating and cooling to the tanks. The cooling is done through a chiller that uses food grade Propylene Glycol. For the heating side, they use a three way valve and run potable water through the jacket and loose the anti-freeze. They just run the heated water on the ground. I want to turn it into a closed loop. How, it another posting.

But my question.

When I asked about the solution, I got the answer that they didn't know what the solution was. So, I checked it with my Misco Refractometer and it was off the chart. I added a drop of water to the plate and it brought it down to -15. I think that they are running straight glycol because that is what they were told to do. I understand that it is so that the water doesn't freeze inside the chiller. So, what is the proper ratio of glycol to water? If the food grade glycol not as potent as the Polypropylene Glycol that I always use on heating systems?

I need to add a circulator to the heat side. Taco and others list there minimum temperatures at levels above 32 degrees. And the motors and controls will have a condensation problem. Wilo lists their circulators to +14 degrees and are protected against condensation wrecking the control boards. What is the "normal anti-freeze ratio? What is the "normal" cold temperature of chilled water.

You need chilled water to lower the temperature when fermentation causes heat, and heat if the temperature goes too low.

The Glycol is "Banner" something. I can't find my notes at this time.

Looking for answers.


  • Rich_L
    Rich_L Member Posts: 81
    Glycol mix

    The mix will depend on the temperature level of protection you're looking for. The most I've ever diluted is 50 - 50. The stronger the glycol solution generally the poorer the heat transfer. I'm sure you already know all about that.

    Is there freeze protection/ low limit on the chiller? As long as you protect to this level you shouldn't need to go any lower, unless there's outdoor ambient concerns.
  • hot_rod
    hot_rod Member Posts: 22,476

    check with the manufacturer of the glycol.

    Dow recommends no more than a 60% maximum blend for efficient heat transfer in their engineering manual, for propylene based fluids. That should provide a -60°F freeze protection, where it freezes solid.

    Glycols generally have two or three temperatures, first where ice crystals form but it still pumps, then slush, then solid freeze.

    A 36% of DowFrost PG, for example gives you burst protection to -60°F temperatures.

    Usually burst temperature is adequate in HVAC applications. At burst temperature it is a slush, not pump-able with a centrifugal pump, but it will not burst pipes, etc

    Glycol is recycle-able and you can sell it to recyclers regardless if it is PG or EG.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Techman
    Techman Member Posts: 2,144

    What temp are they trying to keep  the tanks at?
  • icesailor
    icesailor Member Posts: 7,265
    Chilled Wine:

    I'm not sure. The temperature goes up and down, depending on what stage of the fermentation process they are in. And outside temperature comes into play. Interesting, Wilo is the only circulator that is advertised that it is rated for 50/50 antifreeze. The other ones say only water. But if the fluid has a high viscosity,,,, What does that mean? If the pump has a personal problem in the bed that you are on your own? The fluid that I am going to deal with is only for heating. But the tanks are outside. If they are not making wine when it is cold out, you need the freeze protection. According to the owner this AM, it is recommended  to use a 33% solution. One part glycol, two parts water. Because they never measured how much solution they lost, they had no idea that the solution was getting so thick. It will all end up the same when I have both connected together. It's just that what I am doing will never see cold water.
  • Techman
    Techman Member Posts: 2,144
    edited September 2012

    Hi ice,typically reds are kept around 70-80* during fermentation and whites are between 45-60* but the brewmaster's have their own preference's.So this isn't like a freezer application,15*-0*F.how many gallons tank(s) And typically the steadier the temp the better tasting the wine.
  • icesailor
    icesailor Member Posts: 7,265

    I didn't ask what the temperatures he needed. A lot of things were really overdone. Others, not so much. What is there has existing piping. I'm not trying to re-invent the world. Just make it better.

    Lets say that one tank is 1500 gallons, #2 tank is 1000 gallons and tank #3 is 500 gallons. They all have different loads and different products. So everything varies. They had a lot of thermostatic mixers all over with no checks and cross connections everywhere on the property. I got internal checks to stop all that.

    The problem I was given was the hot water supply. I connected the need to connect the two to make one. The boiler is inside and the tanks are outside. I have a headache making project to figure out a way to go from inside, to outside and back inside. Plus connect the whole mess together. And not have it leak from the weather where the pipes go through the side of the building, and keep it high enough so you don't bang your head on it.

    The chilled water piping is done with sch.40 PVC and whatever fittings. It's all insulated. I'm thinking of trying a PE pipe system I saw at the PHCC trade show with fusion welded fittings. I can't remember the name but they have potable water pipe (blue) heat pipes (green) and non potable grey water (purple). It is Massachusetts approved for Potable (but I'm not doing Potable) and you basically make your own fittings. Except for ells and adapters. You need the heat welder that is electric. I'll have to look into it farther.

    Everyone looses their mind over the thought of the cost of copper but when you add into the cost of hanging PEX and getting it to look straight and professional, and that I would need a new Milwaukee PEX expander, copper looks better. My Expander only goes up to 1" and it struggles to do that. The stuff I saw at the trade show makes PEX look stupid and only for dubbers. PEX is fine where no one will see it but you wouldn't want to brag about it. No matter how hard you try to make it look good.
  • Rich_L
    Rich_L Member Posts: 81
    Glycol make up tank

    You may want to consider a glycol make up tank for this project. We've used them on many commercial jobs. They automatically add a glycol solution (you pre-mix it in the storage tank to the dilution rate you want) based on system pressure. It helps assure your glycol percentage stays the same and takes the guess work out of making up system solution. If they're having to add a lot of make-up I'd want to find out where it's all going... maybe on their "pump and dump" side or when switching from heating to cooling?

    Glycol make up tank: http://completewatersystems.com/product/glycol-makeup-unit/ 
  • SWEI
    SWEI Member Posts: 7,356
    Green / blue / purple pipe

    Was almost certainly Aquatherm http://www.aquatherm.com/

    I've become a huge fan, particularly for sizes above 1" nominal.  Below that, we usually transition to PEX (typically with a Webstone ball drain threaded onto a male NPT saddle fitting.)

    The tooling costs a few bucks, but you can usually borrow or rent from your rep or supplier to get started.  The savings in both material cost and labor over copper are quite significant.  Those welded saddle fittings are the cat's meow for boiler rooms, pumps, and gauges and the stuff is so inert you can run methanol or acetone through it.  It doesn't droop like PEX and the thermal expansion is kept in check by the glass fiber layer in both Climatherm and the hotwater version of Greenpipe.  If you're hanging hot water pipes they do need a bit more frequent support than metal pipe -- about 40% if I had to guess, versus what, 5x as much for PEX?  You'll save on insulation as well, and if you're running chilled water there are very few condensation issues.
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