Winery Refrigeration
Winery Chillers
Winery chillers consist of a closed-loop tubing attached to the heat exchanger of a winemaking vessel. Chillers contain an evaporator, a compressor, a condenser, and an expansion unit. Glycol or a mixture of water/glycol or brine flows through the circuit and cools the vessel by extracting heat from the heat exchanger.
Sizing the Chiller
Because of the wide range of temperatures (loads) required in producing wine, the system must be designed to handle all the different loads as efficiently as possible. The most important issue therefore is to size the chiller accordingly. For most wineries, sizing a chiller means getting the proper tonnage of capacity, and this means wineries should probably involve refrigeration consultants.
Glycol
Water is an excellent secondary coolant because of it is inexpensive and has favorable thermodynamic properties, and is used in some wineries at about 2 to 5 degrees C (36-41°F). However, water has a freezing point of 0 degrees C, (32°F) which limits its use in the winery, i.e., it cannot be used for cold-stabilization. Another option is glycol, a coolant which has a freezing point at about -12.9 degrees C (8.9°F). Glycol comes in two varieties: ethylene glycol and propylene glycol.
Water/Glycol Mixture
Most wineries use a 30 to 45 percent glycol mixture, depending on the application, for their coolant liquid as it provides several benefits over just normal water:
Distribution System
The distribution system consists primarily of water/glycol piping and a pump, or pumps depending on demand. The pump pulls glycol from the storage vessel and cycles it through all equipment to be temperature controlled before returning it back to the storage vessel. This process transfers heat back into the glycol storage vessel. The pump(s) should have a manifold with a non-return valve that stops any flow when the pump is not operating.
Portable Chillers
For many small wineries, the issue with refrigeration has long been the size of the equipment and the cost. Typically, large, stationary systems may be beyond their means; and as a new winery, they might not have a completed structure to house mechanicals and related plumbing.
Click on the following topics for more information on winery refrigeration.
