Your equipment faces general wear and tear over time. Unfortunately, there is no way to prevent it! By being proactive with chiller maintenance, you’ll reduce stress on your equipment, unexpected downtime, and costs.
Before we dive into the maintenance tips, lets start lets by defining what a chiller is. A chiller is a machine that removes heat from a liquid via a vapor-compression cycle, adsorption refrigeration cycle, or absorption refrigeration cycle. This cooled liquid can then be circulated through a heat exchanger to cool equipment, or another process stream. Ultimately chillers are used to dissipate heat, most commonly through the use of a water/glycol solution.
Now that we understand what a chiller is lets look talk maintenance. If you’re looking to improve your chiller maintenance and efficiencies, you’ve come to the right place. Our expert technicians have gathered the top 10 chiller maintenance hacks.
1. TRACK DAILY OPERATIONS
First, keep a detailed log of your chiller operations. By collecting vital information daily, you’ll be able to understand how your chiller is operating. Your log should include information such as:
- Temperatures
- Pressures
- Fluid levels
- Flow rates
- And more
To ease your processes, ensure you automate the collection of this information. Many remote monitoring systems can aid in support.
2. KEEP IT CLEAN
Clean tubes allow for the most efficient heat transfer. Thermal resistance decreases the efficiency within your chiller. To prevent this, spot check for debris such as mud, algae, or mineral build-up in your tubes. A thorough brushed cleaning should be completed at a minimum once per year. Let Rasmussen Mechanical Services help you with all of your preventative maintenance needs.
Bonus tip: Higher approach temperatures indicate efficiency is decreasing. By tracking this in your daily log, you’ll be able to see when temperatures are increasing.
3. TREAT THE CONDENSER WATER
Like a boiler, maintaining high water quality is essential to your chiller. Treated water limits the corrosion and build-up which happens within the unit. Use regulated chemical treatments to help keep the water within your system purified.
Bonus tip: Replace filters often to help maintain the quality of water.
4. WATCH THE WATER
Did you know lower water temperatures improve chiller efficiency? That’s right – you can improve efficiency just by lowering the temperature of the water entering the condenser.
5. GO WITH THE FLOW
As with the temperature of the water, the flow of it also plays a big impact on the efficiency of your boiler. The chilled water flow rate must be above 3 feet per second and below 12 feet per second. If the flow falls below 3 feet per second, your flow may become laminae. If the flow rises above 12 feet per second, vibration and noise lead to the ideal environment of tube erosion.
[Looking to enhance the impact of efficiency on your chiller? Download our HVAC Preventative Maintenance Checklist to keep your chiller running properly.]
6. CHECK THE CHARGE
The amount of refrigerant within a compressor lead is directly related to the amount of cooling a chiller is able to provide. To keep your facility at the desired temperature, check the level of refrigerant. If your levels are low, your compressor must work overtime to keep conditions at the desired level. To keep your equipment running efficiently, charge the refrigerant when necessary.
Leaks, air, and moisture within the system lower the reliability of your equipment. Ensure these three items are not present.
7. PURGE YOUR INEFFICIENCIES
Air and moisture within the system lower the reliability of your equipment. In fact, non-condensable elements decrease efficiency by 4-7%. Because the evaporators operate in a vacuum, these non-condensable elements are able to leak in. Ensure the air and moisture are at an all-time low by purging.
8. COMPRESSOR OIL CONTENTS
Complete a spectrometric chemical analysis of your lubrication oil annually. Please note pressure chilled systems should be analyzed more often. Magnetic friction chillers don’t require this testing as oil has been eliminated from their design. Be sure to read through the results thoroughly to get a full understanding of potential problems as well as oil purity. This analysis will also identify if the oil needs to be replaced.
Bonus tip: If the oil charge is replaced, be sure to also replace the oil filters.
9. COMPLETE THIS CHECKLIST
Ensuring each part of your chiller is operating both properly and efficiently is key to chiller success. Complete a check of the:
- Safety and sensor calibrations based on your manufacturer’s guidelines.
- Electrical connections to the chiller.
- Electrical motor winds.
- Shaft seal of the open drive motor.
- Motor cooling air vents.
10. CUT COSTS WITH VARIABLE FREQUENCY DRIVES (VFD)
Variable Frequency Drives (VFDs) motor speed matches the needed load, offering a more cost and energy-efficient way to operate. They also offer a softer start and lower in-rush of current.
Chillers are a complex unit. In tandem with professional help, you’ll be able to keep your unit operating efficiently. Whether you’re in need of a consultation, repair, strategic chiller maintenance, rentals, or parts, we’re here to help. Reach out to the professionals at Rasmussen Mechanical Services to see what we can do for you.
Additional Thoughts
Chillers are often a facilities single largest electrical load. With such large costs associated with running a chiller, predictive maintenance quickly can become a viable option. This often involves using the latest technology to detect chiller problems before they occur, preventing downtime and lost revenue. This helps you save money by maximizing up-time, efficiency, reliability, and equipment life. By taking into account chiller operational data you will get a better picture of how the overall system is operating. Some common predictive maintenance strategies include:
- Vibration analysis
- Root Cause Failure Analysis
- Oil Analysis
- Laser shaft alignment
- Corrosion analysis
- Ultrasonic flow meter detection
Chiller Safety
As always, safety should be the number 1 concern anytime you are performing maintenance on a piece of equipment. It is important to realize that there are many types of refrigerants used in chillers. Each of these refrigerants have specific safety requirements for leak detection and emergency ventilation.
The EPA also has heavy regulations when it comes to handling of refrigerants as these can damage the Ozone layer. You must be sure to comply with the Clean Air Act and also need to be appropriately licensed to work with refrigeration.
[Learn More About The EPA’s R-22 Phase Out And What It Means To You.]
Chiller Safety Controls
In a good article written by NTT Training, they discuss chiller safety controls and what workers need to know about them. They go on to say:
Usually, a chiller consists of a compressor, an evaporator, and condensers. Each chiller requires different setting that corresponds to the load for maximum efficiency. Every chiller has safety controls that are designed to protect the cooling system from harm. This protects against low refrigerant temperature, low oil pressure, or high condensing pressure.
Some of these controls include capacity controls and refrigerant flow controls. Capacity controls maintain the temperature of the chilled water and refrigerant flow controls are set in correspondence with the compressor used. In the event that these controls fail, the system can be set to shut down. This avoids more serious machine damage that could affect the health of those around.
Trust RasMech With Your Chiller Maintenance
Establish a preventative maintenance plan for your long-term equipment reliability with Rasmussen Mechanical Services today! Call us at 1-800-237-3141, email sales@rasmech.com, chat with a support agent, or contact us online.
You can also reach out to one of our offices in Omaha, Council Bluffs, Denver, Sioux City, Sturgis, Gibbon or Lincoln. Whether it’s air cooled chillers, water cooled chillers, screw chillers, absorption chillers or ammonia chillers, we have you covered.
