A weekly chiller inspection should take less than 5 minutes. This inspection should check for coolant leaks, coolant level and discoloration in the reservoir, dust or debris accumulation on condenser coil fins, proper air flow, and air and coolant filter condition if applicable.
Leaks are rare if the chiller is properly maintained. However, if you notice coolant on the floor near the chiller or dripping from the chiller enclosure, turn off the chiller and disconnect the power. When leaks occur, they are usually due to use of the wrong type of fittings, connections, or hoses. Any leaks should be fixed before the chiller is used again.
Any significant drop in the coolant level in the reservoir since the previous weekly check should also be investigated. If there is no visible system leak, then the loss may be due to equipment leakage elsewhere, such as within the application itself. Coolant should be added if the coolant level site tube on the front of the chiller approaches the half-full mark. (See Figure 3.)
Condenser Coil Fins
For maximum thermal performance, the condenser coil fins should be free of dust and debris (Figure 4.) Therefore, checking the condenser coil fins weekly is especially important if the system is in a dusty environment and is not fitted with an air filter. To check the condenser, remove the front grill by sliding it upward, pulling the bottom out, and pulling it straight down. Use a fin comb, soft paint brush, or shop vacuum to remove any debris and keep the fins clean. You may also use compressed air (60-90 psi) to blow off dust from the condenser coil fins. This will maintain the proper airflow and allow for better cooling of the refrigerant. Caution should be taken though when cleaning the fins, since they are sharp and can also bend relatively easily.
In addition to keeping the condenser coil fins clean, proper ventilation should be maintained around the air-cooled chiller. Inadequate ventilation will cause a decrease in cooling capacity and, in a worst case scenario, a compressor failure. The area around the chiller must be kept clear and unobstructed in order for the chiller to work properly. The two sides and back of the chiller should have a minimum clearance of 18" (46 cm), and the top clearance should be at least 6" (15 cm) to allow for proper air circulation. It is also important to ensure that the hot air exiting the chiller does not recirculate into the inlet openings. The front of the chiller must have an ample supply of ambient temperature air. During a weekly inspection, clearance should be checked. Chillers are usually on casters and therefore can be moved, either intentionally or unintentionally, if the brakes aren't on.
Chillers are normally very quiet units. Therefore, any abnormal sound or substantial increase in noise level since the last inspection may indicate an impending pump, fan, compressor, or coolant blockage problem. It's important to investigate the cause of the noise and perform necessary service to prevent system downtime. Pumps and fans can be replaced relatively easily, as can hoses or other components. However, it's best to purchase these before your system is down due to lead time needed for shipping replacement parts.
A water filter is an option available on most chillers. (See Figure 5.) With a new system, the water filter can quickly accumulate foreign matter introduced during system setup. This can lead to a decrease in system performance in a short period of time. If you have a water filter installed, inspect the filter cartridge one day after you set up a new system to ensure the filter is clean and the system runs at maximum capacity. After this initial filter inspection, it is recommended that the water filter be checked monthly.
A deionization package is another option available on chillers. The deionization cartridge's life, like most parts, is a function of the application. The water resistivity should be checked weekly and the cartridge should be changed if needed.