Refrigeration and freezing systems can account for a large portion of a facility's
energy usage and therefore are excellent targets for energy efficiency improvements.
There are four main energy saving categories for these systems: Operations and
Maintenance(O&M), compressor and condenser improvements, and a general category
of improvements.
- O & M Savings
- Set temperatures to the lowest possible setting.
- Don't overload your units beyond their capability.
- Clean coils to improve heat transfer.
- Don't position units in confined areas where heat cannot be vented properly.
- Compressor Modifications
- Install variable speed drives (VSDs) and high-efficiency motors on compressors.
- Use auto-unloading to reduce compressor work when the system is not
fully loaded.
- Condenser Modifications
- Install variable speed drives (VSDs) and high-efficiency motors on condenser
fans.
- Mechanical subcooling is a method of increasing the efficiency cycle
by using an additional heat exchanger in the refrigerant cycle.
- Oversizing condensers will increase the heat exchanger area and improve
the efficiency of the refrigerant cycle.
- General Improvements
- Install controls on anti-condensate heaters in order to minimize run-time.
These controls sense the humidity in the air and only operate the heaters
when needed.
- Open-drive motor systems, as opposed to hermetically sealed motor systems,
can make your refrigeration system more efficient by allowing their motors
to reject waste heat into the air, instead of back into the refrigerant,
thereby reducing the cooling load.
- Delamping and use of high-efficiency lighting not only reduces lighting
energy needs, but also reduces the amount of heat being introduced into
the space that is being cooled.
- Night covers on open refrigeration units are another way to reduce your
cooling load.
- Glass doors or plastic curtains reduce heat gain from the environment.
- Heat pipes are devices which are actually installed on the HVAC equipment
of buildings which operate refrigeration units. They reduce the humidity
of the air inside the building, thereby reducing icing on refrigeration
display cases. This can save 12 - 15% of total refrigeration costs.
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