Can an Older Ammonia Refrigeration System Still Be Efficient
Across Central Washington, ammonia refrigeration systems keep fruit warehouses, food processing plants, and cold storage facilities running season after season. Many of these systems have been in service for decades, and for good reason. Ammonia is an efficient, proven refrigerant that works for a variety of commercial uses.
Even so, efficiency levels in refrigeration systems begin to taper over time, increasing costs and making it harder to keep temperatures stable during harvest season. This leads many facility managers to ask whether an older system is worth investing in or whether it’s time for a full replacement.
The good news is that an older ammonia system can run more efficiently with the right upgrades, maintenance, and tuning so that you don’t have to start from scratch.
Why Older Systems Lose Efficiency
Ammonia systems don’t become inefficient overnight. Instead, small issues build up over time. The primary focus is identifying where energy is being lost and addressing those areas strategically.
Common reasons why older ammonia systems lose efficiency are:
- Worn or aging compressors that require more energy to maintain the required temperatures
- Dirty or fouled condenser and evaporator surfaces that reduce heat transfer
- Refrigerant charge or circulation issues that make the system work harder
- Air, moisture, or other contaminants within the system
- Aging controls or sensors that no longer regulate equipment as efficiently
- Fans, pumps, and motors that have become less efficient over time
- Insulation that has deteriorated or become damaged
- Incorrect operating pressures or system settings
- Deferred maintenance that allows several small efficiency problems to accumulate
Upgrade Controls for Smarter Operation
Controls or programmable logic controllers (PLCs) are an effective way to manage compressor functions. While some compressors may require a higher level of control, older PLCs and compressor controls may not account for changing system needs or building conditions.
Modern systems can allow for compressor sequencing, suction pressure regulation, and other specific adjustments. Control systems with floating head pressure regulation can also lead to significant energy savings by adjusting head pressure based on ambient temperatures. These features can be especially useful in Central Washington, where ammonia systems may experience lower temperatures overnight and during the spring and fall.
Improve Condenser Performance
Heat rejection is a crucial part of the system if consistent, stable temperatures are to be maintained. When heat is not properly expelled, compressor power consumption can increase as a result.
If the condensing units are evaporative, scale buildup, deposits, and biofilm can form in the tubes and reduce heat transfer efficiency. If the problem is related to water quality, water treatment and regular inspections should be performed.
Other ways to improve efficiency include optimizing condenser capacity through variable frequency drives, upgrading failed components, and adjusting fans.
Evaluate Compressor Efficiency
Compressors generally represent the highest percentage of energy consumption in a refrigeration system. Compressor efficiency may deteriorate over time, especially if the equipment frequently operates below full capacity. Analyzing compressor performance and efficiency can help identify the most cost-effective options for optimization.
These may include modifications or upgrades to compressors that no longer meet the needs of the system, such as switching to a variable-speed or screw compressor, or reconsidering compressor sequencing when reciprocating compressors are used.
Add Variable Frequency Drives
Finally, one of the best upgrades many older ammonia refrigeration systems can make is adding variable frequency drives to compatible components.
Variable frequency drives (VFDs) can be used with fans, compressors, condensing units, and pumps. By reducing motor speed when full capacity is not needed, VFDs can significantly reduce electricity consumption. For centrifugal fans and pumps, power demand can decrease substantially as speed is reduced. VFDs may also help extend equipment life by reducing pressure fluctuations, vibration, and mechanical stress.
For many existing ammonia refrigeration systems, adding VFDs can be a cost-effective way to improve overall efficiency.
Stay on Top of Maintenance
All of this points to one fact: routine ammonia system maintenance can help prolong equipment life and improve efficiency. Regular maintenance should include:
- Purging the system of non-condensable materials
- Managing oil levels
- Cleaning coils
- Replacing worn or damaged valves
- Checking pipe insulation
- Inspecting for leaks
- Performing preventive maintenance on mechanical equipment
Tune the System to Match Today’s Needs
System tuning is another effective way to improve efficiency. Older ammonia systems should be tested and adjusted to ensure they continue to meet the needs and demands of the facility. As a building grows and evolves, its refrigeration needs may change as well. If your facility has grown over the years, and the ammonia system is no longer operating under the conditions it was originally designed for, it may be time to make adjustments.
A refrigeration system audit involves inspecting and evaluating all aspects of a system’s operation and design to determine the best approach for improving its functionality, performance, and efficiency.
Is It Time to Upgrade or Replace?
Not every older ammonia system needs to be replaced. In many cases, targeted updates and improved maintenance can extend equipment life and improve efficiency at a fraction of the cost of purchasing a new system. A professional assessment is the best way to determine what improvements will deliver the best return and help you plan upgrades over time. It’s also possible that you may qualify for local energy efficiency incentives.
Frequently Asked Questions About Older Ammonia Systems
How do I know that my ammonia system is running inefficiently?
Signs of efficiency loss include growing energy costs, fluctuating temperatures during refrigeration, unnecessary compressor usage, and system malfunctions.
Are variable frequency drives recommended for older systems?
Depending on the system, these devices may cut energy costs, reduce wear and tear on equipment, and dramatically extend the equipment’s lifespan.
Can upgrades improve safety as well as efficiency?
Yes. Modern controls, regular maintenance, and updated components can improve monitoring, reduce the risk of leaks, and support safe operation.
Get More from Your Ammonia System with Central Washington Refrigeration
Your old ammonia system may have more time and efficiency left than you realize. Central Washington Refrigeration helps facilities evaluate, upgrade, and maintain ammonia refrigeration systems to improve performance and reduce operating costs. Contact Central Washington Refrigeration today to schedule a system assessment and find the right path forward for your facility.