What Is A Glycol Chiller and How It Works Best
A glycol chiller is an electrically powered unit, often also referred to as a power pack. It serves as the power source for circulating a liquid coolant mix with water to keep beverages at optimum temperature when dispensing and serving. Current models use Propylene Glycol, a food grade coolant, similar to anti-freeze. Older models still be in operation may use Ethylene Glycol, which is typically pink in color. Ethylene Glycol is not considered food grade, and is hazardous/poisonous if consumed in significant quantities, so it is to be avoided. We would also advise against using standard anti-freeze in many units, depending on manufacturer, as it may tend to jell in the system and cause operational failure.
Like many refrigeration units, including refrigerators and walk-in coolers, glycol chillers have compressors that use various types of refrigerant. Our chillers use R404A gas refrigerant.
The ratio of the propylene glycol/water mix is often one part glycol to two parts water, but that may not always be the optimum ratio. Always refer to manufacturer’s specifications. Some smaller units might use equal parts water and glycol. Do not use pure glycol or pure water in a glycol chiller.
If the glycol-to-water ratio is wrong several problems may occur. If too much water is in the mix, ice will build up in the reservoir and potentially block the circulation of the mix. If too much glycol is in the mix, the unit may not be able to get to down to standard operating temperature. Each circumstance may ultimately cause operational failure.
Our chillers utilize a sealed glycol reservoir in various sizes, from the smaller ones to largest. ( 1 U.S gallon to 12 U.S. gallons.). Sealed reservoirs are considered superior to models with open reservoirs, because sealed reservoirs prevent dust and foreign objects from contaminating the glycol mix. We recommend that the blend be replaced every 1-2 years. A clean mix, properly maintained, is essential for operation and will provide years of trouble-free service.
One or more rotary vane pumps constantly circulates the glycol/water mix through copper or polyethylene tubing. One line serves as the outlet, the other line serves as the return. They are looped together at the end, inside of towers, shaft boxes, or any similar pouring station, where beer or other beverages are dispensed. These are often simply called glycol lines. Product lines are wrapped and insulated around the central glycol lines, so that cold temperature can be maintained from one point to the end. Recommended temperature of the glycol mix will vary from manufacturer anywhere from 27* F – 32* F.
Two glycol lines are sufficient for bundles of eight product lines. When additional products are needed, more glycol lines must be added. The idea here is that each individual product is in contact with the glycol line. For example, four glycol lines are used in bundles of eight to16 products, and six glycol lines are used in bundles of 17 to 24 products. Lines are wrapped with moisture barrier tape and sponge rubber insulation with a vinyl exterior. Insulated bundles are also referred to as beer conduit and trunkline.
Glycol chillers are designed to function in conjunction with walk-in coolers and are somewhat dependent upon proper function and limited in their capacity. In other words, kegs must still be kept refrigerated. A chiller cannot be the sole source of cooling, nor can it be used to chill a warm keg down to correct temperature. If the walk-in cooler is too warm, your chiller will most probably not be able to compensate and you’ll have foamy beer at the dispenser. When properly designed with the correct expansion valves, these units may be installed outdoors or inside a walk-in cooler. If kegs are stored at room temperature a flash chiller would be required.
Like any mechanical machine, glycol coolers are best utilized when operation is at or below normal room temperature. Improperly stored, refrigeration units may get too warm during the summer months and experience pump, motor or even compressor failure. We recommend they be installed in a room or area with excellent ventilation, on a level surface and kept under 75* F.
FREQUENTLY ASKED QUESTIONS ABOUT GLYCOL CHILLERS
Why would I ever need a glycol chiller?
At your brewery, restaurant or other facility, you may want to serve beer and other beverages to a remote serving location from your kegs or other vessels. In some circumstances where your may have a relatively small number of products that need to be pushed only a short distance, proper function can be achieved through use of an air circulation system. Blower fans push cold air from the walk-in through an insulated air shaft around the beerlines, to the remote serving station and back to the walk-in cooler, creating air circulation at refrigeration temperature, sufficient to keep the beer cold enough that it doesn’t foam. Those systems are limited in capability to approximately 25-4O ft. You will need to compensate for heat generated from the electric fans. Once again they are dependent upon a good refrigeration source. Most beers will foam, even at low carbonation levels, when internal temperature rises above 40 * F, no matter what you try, since CO2 in solution and in our atmosphere becomes more active the warmer it becomes. At some point it becomes much more worthwhile to utilize a refrigerated glycol chiller system when more products are desired and/or when longer distances are required.
What glycol chillers do we stock?
1/5 h.p., 1/3 h.p., 5/8 h.p., 5/8 h.p. double pump. They each have a distance range respectively of 150 ft., 225 ft., and 375 ft. They are pre-set and should not be modified with any form of flow control. If you have many products at greater distances, or multiple locations, requiring larger units, 1 h.p. units are available upon custom order request.
Would I need a glycol chiller for beverages other than beer?
Perhaps and perhaps not. The rule of thumb is if the beverage is carbonated it can be dispensed cold and consumed at a warmer temperature. Many craft brewed beers natural flavors develop at that higher range 45 * F or more, yet still dispensed under 38* or lower. Glycol chillers are traditionally designed for beer. However we firmly believe they’ll work wonderfully for any carbonated beverage containing alcohol or not. Mead, cider, hard seltzers, kombucha and keifers are all growing in popularity and you may wish to use beer equipment to dispense them. Much will depend upon the producers recommended consumption and volumes of CO2 in solution. Beer is probably the most difficult beverage to properly dispense. For example sparkling wines and sparkling meads can be stored at slightly higher refrigeration temperatures, and moved through separate lines with less insulation at different pressure. Some experimentation may be required. Many red wines do not require refrigeration at all and should be pushed with a suitable inert gas, such as Argon or Nitrogen, outside of the beer conduit. Ciders should be kept refrigerated and dispensed at equal levels of pressure to maintain volumes of carbonation as the keg/vessel empties. Products with low levels of carbonation will dispense well, most probably even easier and allowed to warm in the glass. Products with very high levels of carbonation have a tendency to overly ‘spawl or spray’ out of the spout, when moving through a standard beer faucet, and a flow control faucet may be required for best results.