This chiller maintenance checklist will help you ensure you catch all of the important areas of your chiller system. In this post we’ve provided an air cooled chiller maintenance checklist as it is the most common design.
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Air Cooled Chiller Maintenance Checklist
Follow this list as you inspect and maintain your chiller. Each item is important and diligent chiller maintenance will save money and make the system last longer.
- Inspect water inlet and outlet for leaks
- Clean out and inspect the sump for corrosion
- Cooling coils need to be inspected and surfaces cleaned. Check for leaks, corrosion, or bent fins
- The zone control actuators should be inspected, cleaned, and all adjustments made
- The compressor needs various areas checked, these include: refrigerant charge, vibration, crankcase heater, oil levels and changes, operating temperatures, and if there are any leaks of refrigerant or oil.
- Condenser fans should be cleaned, bearings need to be checked for wear and lubricated, and belts and couplings need to be checked and tightness checked or adjusted as necessary.
- The condenser coil should be check for corrosion and leaks and all finds or combs need to be checked for bent sections.
- The electrical disconnect should be inspected for proper operation and the contacts should be inspected and cleaned.
- The exhaust air damper needs to be inspected for proper operation, have the bearings lubricated, and calibrate or adjust it for optimal operation.
- Return air dampers also should be checked for proper operation, calibration, and bearings be lubricated.
- The fresh air damper should also be inspected, calibrated, and bearings lubricated.
- The filter dryer also should be inspected and any old, dirty, or damaged filters be replaced.
Chiller Maintenance Tips
The simple fact is that the chiller makes up for a significant portion of your electricity usage, even at peak performance. If you’ve got maintenance issues it can easily use an extra 10%, which hurts the bottom line. While technology has improved to remotely monitor chillers and technology has produced more durable and efficient parts, maintenance is still key.
Maintain A Log Daily
Knowledge is power and saving power is a big deal when it comes to chillers. Recording operating conditions such as flow rates, pressures, fluid levels, and temperatures helps build a useful record of your system. While it was standard to do bi-monthly checks today’s continuous monitoring technology allows you to keep accurate daily logs that will help you narrow down maintenance issues before there’s a bigger problem.
Condition Your Water
Corrosion and scaling are always a challenge in air cooled chiller systems. Treating the water in your system helps cut down on corrosion, scaling, and the growth of biological contaminants such as Legionella. All of these issues can let to a decrease in heat transfer caused by fouling and diminished heat transfer due to build up inside of pipes. It’s important to continually monitor your chilled water loops remotely and visually inspect them annually.
Clean Heat Transfer Tubes
A big part of the efficient operation of chillers relies on clean heat transfer tubes. If your system has mud, minerals, algae, or scaling it will coat the inside of the tubes and insulate them. While insulation is great at keeping heat out of a home in the summer the heat transfer in chillers is the cornerstone of how the system functions. Neglecting your chiller tube cleaning will end up inflating your operating costs and likely result in additional maintenance and more frequent downtime.
Maintain Refrigerant Charge
Your chiller’s ability to cool relies on having the right amount of refrigerant. To ensure your systems optimal efficient performance make sure you’ve got the right level of refrigerant. If there is air, moisture, or leaks in your system it will impact it’s performance. With insufficient refrigerant it will take more electricity for your system to perform the same cooling effect.
Provide Cooler Water
Providing cooler water for the condense improves the chiller’s performance. It will not have to work as hard to condense the water and will run more efficiently. In some cases this technique can compensate for problems with coils. While this does fix the problem it is a temporary solution as the chiller must work harder for the same effect.
Chillers function on the principle of condensing refrigerant to cool. If moisture or air leaks into the system it introduces non-condensable elements into the system that rob it of efficiency. The percentage can be as high as 7% below the rated performance of the chiller system you have. When considering how much energy a chiller uses to begin with and extra 7% adds up quickly.
Maintain Appropriate Flow Rate
The rate at which your chilled water flows through the chiller does impact the chiller’s performance. If it is too slow it lowers efficiency. Too fast and it will cause erosion, vibration, and noise. It is best to keep the flow rate of your chiller somewhere between three and twelve feet per second. The exact speed will depend on your chiller’s design and the load needed by your location.
Upgrade To Variable Speed Drives
In most cases the chiller motor is the largest draw on electricity in the entire building. Single speed drives are on or off and cannot adjust for the difference in load the system is running under. In contrast a variable speed drive saves energy as it can adjust the speed to match the load. This saves a significant amount of energy in your chiller system. In addition variable speed allows the system to ramp up more smoothly in the case it is turned on in an emergency situation.
Check Oil In Compressor
If your compressor uses oil make sure you send a sample of it for inspection at a laboratory once per year. Due to the hermetically sealed nature of a close refrigerant system the compressor oil should only be changed if the lab deems it necessary. If there’s excessive moisture it can point to there being a problem with purging the system effectively. If the oil is changed ensure the filters are tested and replaced when there are pressure drops. In the case your system uses magnetic bearings and is frictionless your system will not have compressor oil.
Inspect Motors & Starters
You can save energy and downtime if you inspect your motors and starters. To do so inspect the sensor calibration and safety on the microprocessor controls. Also take the time to inspect the wiring and connections in your chiller system at common wear points and hot spots. Pay attention to signs of refrigerant leaks and test motors for insulation faults.
When To Inspect Chillers
Chillers should be inspected and maintained at least 2 times a year in areas where they are only used during the cooling seasons, or 4 times a year in areas that cool in all 4 seasons. Quarterly inspection helps your chillers, HVAC system, and cooling towers last longer and run more efficiently.
Maintained Chillers Operate More Efficiently
Using this checklist you can get better performance out of your chiller and cooling system. The better maintained your chiller is the less energy it uses, and that saves you money on utilities. As the chiller and HVAC system is one of the largest draws of electricity in many commercial, industrial, and medical facilities it is important to inspect, maintain, and repair chillers. Regular inspection and chiller maintenance will help save money and make the system last longer.
Chiller Maintenance in Arizona
If you have a property such as a commercial building, medical facility, or industrial site that uses chillers for processes or HVAC All Kote Lining, Inc can help you take care of the chiller maintenance you need to keep your energy use down and make your equipment last longer. We inspect, maintain, repair, and line chillers with the most durable coatings available. Give us a call today to find out what we can do for your company at 480-966-4446.