Portable chillers provide heat removal and temperature control for industrial lasers, EDM machines, CNC lathes, and other temperature-sensitive equipment and processes. However, if the chillers are not maintained properly, their performance can degrade gradually, resulting in temperature variations that adversely affect productivity and product quality.
Most portable chillers do not require a great deal of attention to keep working effectively. By periodically performing just a few simple and straightforward preventive maintenance tasks, you can help ensure that your chiller provides years of dependable service.
1. Inspect and Clean the Air FilterAir-cooled chillers rely on a steady flow of air over the condenser coils to maintain proper cooling performance. An air filter is used to cleanse this incoming air and prevent dust, dirt and other airborne debris from clogging (and thus insulating) condenser fins and other sensitive components.
A dirty air filter restricts the flow of air your chiller needs to perform properly. The filter should be inspected weekly and cleaned as required. Most filters are removable and can be cleaned with a mild detergent and warm water or blown out using clean, dry air. Any dust or dirt that has gotten inside the chiller or on the condenser coils should be removed using compressed air. Never use a brush or other mechanical device as it might bend or damage the fins.
2. Check Heat Transfer Fluid LevelsThe heat transfer fluid in your chiller is the lifeblood of the cooling system; without it, no cooling can occur. Keeping the cooling system full helps ensure optimum heat removal.
Some gradual fluid loss can be expected in even the most tightly closed system. Most chillers are equipped with a sight glass, liquid-level gauge or other mechanism that allows you to check the coolant fluid level quickly. You should do so weekly and add coolant as needed. Even if your chiller is equipped with an automatic fluid makeup system, it is still a good idea to visually check the fluid level periodically to verify that the fluid makeup system is operating correctly.
3. Check Heat Transfer Fluid Cleanliness and PropertiesIn many processes, dirt and other particulate can make its way into the circulating heat transfer fluid. These particles can damage the pump, clog valves and filters, and otherwise impair chiller operation. The cooling or antifreeze properties of water/glycol mixtures and other heat transfer fluids also might deteriorate over time.
The heat transfer fluid should be drained and filtered monthly to remove particulate. If large amounts of debris are present, the chiller also should be flushed out with clean fluid to remove any residual deposits. This also is a good time to inspect and clean/replace any fluid filters.
Before refilling your chiller with the cleaned or filtered heat transfer fluid, check the fluid with a refractometer or another analysis instrument to make sure that it has not lost any of its cooling or antifreeze properties.
4. Inspect the Physical Location and ConditionThe environment in which a chiller is installed is always subject to change -- sometimes even quite rapidly. Conditions that no longer meet the manufacturer’s specifications can adversely affect the system’s performance.
The physical location and condition of the chiller should be checked every six months and the appropriate corrective actions taken. Make sure that adequate space exists around the chiller to provide proper airflow and that the ambient air temperature is cool enough from effective heat dissipation. Check external hoses and connections for leaks, and inspect external insulation for wear or damage. If maintaining a particular pressure is critical to your process and your chiller has a fluid bypass or diverter valve, make sure that the valve is adjusted properly. Lastly, make sure that the electrical power and amperage are correct and that electrical wires have not become frayed or damaged.
Performing regular preventive maintenance will help you optimize the uptime of both your chiller and the process it is cooling. Your best source for information on proper maintenance and troubleshooting is the chiller manufacturer. Read the operating and service manuals that came with your chiller thoroughly, and adhere to manufacturer’s recommendations. Equally important, make sure those manuals are readily available to yourself and others responsible for chiller operation and maintenance.