Energy Reduction

Refrigeration Equipment

It's important to upgrade refrigerator appliances when necessary with equipment that has better insulation, improved heat transfer surfaces, more efficient compressors, more precise temperature control and includes defrost mechanisms. New equipment reduces compressor run time and eliminates excess heat.

You should replace chillers with more efficient models once they're 10 years old or more. The newest, most efficient models operate at an efficiency of 0.50 kW/ton, and save approximately 0.15 to 0.30 kW/ton over older equipment models.

Use intelligent refrigeration controls properly by matching equipment needs with system goals. Refrigeration control technology includes:

Variable frequency drives (VFD): utilize sensors to operate fans at required speeds. This
saves energy and reduces equipment wear.

Demand refrigeration and defrost cycles: shut down the refrigeration system at a
pre-established temperature, and return the system to the desired temperature.

Load shedding: uses sensors to measure electrical activity and turns off or delays the start
of equipment if the machines are not needed.

Anti-sweat heater controls: minimize the power usage of the systems that control
condensation. This saves energy by coordinating heater use with condensation levels.

Floating head pressure: allows pressure to vary based on outdoor conditions, rather than
continuously operating regardless of system load. This improves efficiency and extends
equipment life.

For further information on reducing energy and costs by using refrigeration controls visit Reduce Energy Costs with Intelligent Refrigeration Controls.

 

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Additional energy-saving tactics

• Properly charge refrigerant, which eliminates excessive compressor and fan motor cycling. For more information on optimizing chiller operations and reducing energy, visit Energy Saving Strategies for Chiller Operations.

• Follow refrigeration system manufacturer recommendations, which includes keeping the fan vent, coils, and filters clean and free of dust. By following manufacturer recommendations, the risk of overburdening the compressor and fans will be greatly reduced.

Shift the compressor, motor, and fan operation away from peak periods to help reduce demands on the refrigeration system. 

• Use higher-efficiency distributed compressor refrigeration systems as opposed to central compressor systems. Distributed compressor systems can match each refrigerated load requirement during multiple loads, and can lower line pressure drop through removing long pipes.

• Use waste-heat recovery, which recovers energy and improves indoor air quality. For further information on benefits of heat exchangers Air-to-Air Heat Exchangers Recover Energy and Improve Air Quality.

• Use two-speed fan motors in cooling towers with fan cycling. VSDs offer the most efficient control method.

• Use evaporative condensing in chillers, which produces a lower condensing temperature and fan energy usage. This minimizes energy usage as compared to air-cooled condensers, and can be especially beneficial in warmer climates.

• "Floating" head pressure control allows the compressor head pressure to fluctuate with conditions outdoors, which improves energy efficiency, reduces compression ratios, and extends compressor life. 

• Primary-secondary loop configurations should be used for chilled and condenser water, when possible. Multiple secondary fluid loops that coordinate with refrigerated temperature requirements increase the average effective evaporator temperature of the system.

• Use systems with humidity sensors, which match condensation load with heater usage for refrigeration systems. Most refrigeration systems use heaters to control condensation.