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Does PRO sell direct or only through distributors?

About 50% of the systems we manufacture are sold directly to the end user, these range from small boutique wineries to Large Food Processing Plants. It is true that a company can often save a few percent by purchasing direct, but you should keep in mind that buying direct does place more responsibility on the purchaser. Many details such as; shipping coordination, warranty repairs, installation scheduling, rigging, etc will need to be taken care of by the purchaser.

If you are working with a contractor, consultant, or equipment supplier, we would be happy to work directly with them to coordinate a system proposal with load estimate and options and features. For a referral to a dealer that covers your region, please give us a call.

What is Propylene Glycol?

Propylene Glycol is simply a Food Grade Antifreeze, required when a food product is being cooled and there is a chance of direct contact between the two mediums. The glycol, mixed with city water, enables us to operate our chiller systems in the 20 F-35 F Design Operating Temperature Range.

What Type of Glycol Should I use?

Pro recommends that all of our chiller systems are operated with ProChill Heat Transfer Fluid, and inhibited glycol with corrosion and rust inhibitors. Click here to purchase ProChill Heat Transfer Fluid.

What Percentage of Propylene Glycol Will My System Require?

PRO recommends to maintain a glycol freeze point of between 20-25 F below your chiller setpoint. In 90% of applications this equates to a 33% Glycol Concentration. In colder climates you may need to operate with a stronger concentration, but keep in mind the stronger the concentration the lower your system cooling efficiency.

The temperature of the refrigerant will be 10° to 15° F below your Chiller System setpoint temperature. So with a +27° Glycol Temperature, your refrigerant temperature is probably +12° to +17° F.

We require the freeze level of your Glycol/Water Solution to be 20°- 25° F below your chiller system setpoint.

In colder climates make sure that the glycol freeze level is lower than extreme ambient conditions. We do not require the freeze level to be 20 F. below winter extreme conditions. Most Pro Chiller customers will operate with a 35% Glycol to 65% Water Solution. This will protect the Glycol/Water Solution from freeze up to +1 F.

Click here for our glycol freeze point concentration chart

How Much Glycol Will I Need For My System?

The amount of glycol will vary in each application. When attempting to calculate the amount of glycol need make sure to factor in addition to your glycol tank capacity, piping capacity, vessels heat exchangers volume, etc.

Calculating your total system volume can be tedious but an improper glycol percentage will greatly affect the systems operating efficiency. A rough estimate can be calculated by adding the estimated volume of your total system piping, plus your tank jackets, and the reservoir size on your chiller system. Your plumbing contractor and tank manufacturer can help with piping and jacket volume estimates- the chiller system tank capacity should be listed in the owner manual or by calling the factory at 800.845.7781 and providing your system Serial and Model number.

After you've calculated the rough estimate, we suggest you add propylene glycol and water at a 50/50 concentration until your storage tank is at least 50% full. Allow the system to circulate for 15 minutes and then check the percentage using a refractometer. The chart below provides conversion to degree brix. Based on this reading you can then adjust the ratio of glycol to water to complete the charge of the system. For most applications a freeze point between 0 and +5 F is ideal.

Click here for our glycol freeze point concentration chart

For more information please refer to our all about glycol article.

Compressor Will Not Run

Possible Causes Corrective Steps
Chiller or Stager Switch OFF / Circuit Breaker Tripped Reset Switch / Circuit Breaker
Fuse Blown Check Electrical Circuits and Motor Windings for shorts or grounds. Investigate for possible over- loading. Replace Fuse or reset Circuit Breaker after fault is corrected.
Thermal Overloads Tripped Reset any tripped thermal overloads, Check unit

High Suction Pressure

Possible Causes Corrective Steps
Excessive Load Reduce Load or add additional cooling equipment
Expansion Valve malfunction Check Superheat of TXV, replace if necessary

Low Pressure Freeze Alarm

Possible Causes Corrective Steps
Wrong Pump Rotation Reverse the rotation of the circulation pump (Clockwise from motor end)
Evaporator Freeze Up Check Glycol Percentage. Percentage must be at least 20 F below thermostat set point.
Incorrect Freeze Point setpoint Adjust freeze point for application, consult factory.

Compressor Will Not Unload

Possible Causes Corrective Steps
Unloader mechanism defective Replace mechanism
Faulty Thermostat or Pressure Control Check settings of the device, replace if necessary


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