Chilled Water for Wineries

[tmprider]

Does anyone have recent experience with chilled water systems utilizing chillers for wineries, specifically dealing with jacketed storage tanks and the fermentation process.

 

[ClydeMule]

tmprider,

Most of them have been for breweries, but the same thing happens.

I have sold a few of these for this application. Generally a 30% propylene glycol mix is circulated through the system. I have seen systems that have 2-way solenoid valves on the tank that are actuated by a process controller (usually on/off) and some that just run it through.

The tanks are usually very well insulated (dunno the R-value) so the heat being removed is what is generated by fermentation, and what ever pull down is required.

The ASHRAE Refrigeration hand book has a pretty good section on this. Basically the heat produced is a function of the degrees Brix, or the sugar content of the wine. The required temperature will be a function then of the variety. In brewing the different beer styles are dependent linked to a specific yeast, which in turn has a certain temp. range.

I would say you are ususally holding the tanks in the mid 60's. There are also occasions in which the entire batch must be "crash cooled." In brewing this is part of a filtering clarification process. In wine, I think it has the same benefit but am not sure. A lot of times the beer/wine is taken to 30-35 F. You will seriously derate a chiller's capacity when you do this, but usually it is one batch at a time. The last winery chiller I sold was a 15 ton. They had 5 tanks total, 1500 gal/ea. They would only crash cool one tank at a time, so it did not really matter if the chiller was derated.

However, you must make sure that the chiller can operate at these lower temps. It goes beyond derating, it is a question of proper compressor application. I prefer to build brewery chillers that use 404a as opposed to R22, and rated for full capacity with 30F, 30% glycol. It lopes along then at the warmer temps, and runs like a champ with 15-20F glycol. This may not be so big a deal in wine, but in brewing if you do lagering (as opposed to ales) the glycol temps are super low.

I hope this helps. Like I said, the ASHRAE fridge manual has a lot of good info.

Cheers,

Clyde