Blue Pearl Supermarket, Dubai
January 9, 2019
Al Marai Saudi Arabia Display Refrigerator
February 11, 2019

Energy Efficiency In Supermarket Refrigeration

From large hypermarket chains to mini-market owners, it is always a priority to reduce energy costs, 50% of which are from display refrigerators and freezers, sometimes even more depending on the type of cabinets selected. Refrigeration component companies are ceaselessly working on developing the next product that will improve energy efficiency and help the supermarket owner reduce his or her energy bill as much as possible. In this article, we will discuss the type of condensing units we provide, and features of our refrigeration systems that improve energy efficiency.

Types of Condensing Units

Semi-Hermetic Reciprocating Compressor Condensing Unit:

Semi-Hermetic Condensing Unit

The reciprocating compressor is arguably one of the oldest compressors ever designed, and to this day it is still the most popular in the refrigeration industry. Benefits of a semi-hermetic compressor:

  • Universal, the compressor is compatible with all gases.
  • High refrigeration capacity to power requirement ratio.
  • Valves made of high quality impact resistant spring steel.
  • Oil lubrication system includes an oil pump to ensure sufficient oil return to the compressor.
  • Replaceable, maintenance can be performed in the field. 
  • With the use of an electronic frequency controls, there is a continuous variable speed control.

Scroll Compressor-Condensing Unit:

Scroll Condensing Unit

Concept: A scroll set uses two scrolls with identical geometry, one is rotated 180 degrees and placed in the gaps of the other. The upper scroll is stationary; the lower scroll is moved by a motor shaft in an orbital pattern. The orbit decreases in size the closer you get to the centre; hence the gas is compressed as it moves along to spiral to the centre. Benefits of using scroll technology in a condensing unit:

  • The number of moving parts in a scroll compressor is low, making it very reliable.
  • Lower noise emissions.
  • Low cost of manufacturing due to the fewer number of parts.
  • More efficient method of compression.

Mitsubishi DC-Inverter Condensing Unit:

    Our newest innovation, the DC Inverter compressor unit, where compressor capacity is modulated by a DC Inverter, and the lubrication system is controlled by electronic expansion valves for optimum performance. For more info please check the following article:

Energy Efficiency Features:

Cabinet Model Shobak

Glass Door Cabinets:

    In the last couple of years, our main focus in design has been on glass door cabinets. This is due to a couple of reasons: The first is that the market has been moving in this direction. Second, the size of the compressor required for a glass doors closed cabinet is much smaller than an open cabinet of the same size, and energy efficiency can increase by 50%, drastically reducing its cost of operation. Third, the temperature of a cabinet is much more stable when it is closed than when it is in an open cabinet.

Variable Frequency Drives (Inverters):

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Variable Frequency Drive

   Variable Frequency Drives are a type of motor controllers that operate by varying the speed of a motor, this is done by adjusting the frequency and voltage of its power supply. They are used to match the output of a motor to the requirement of its application. In Refrigeration, the cooling load in any given cabinet is always changing according to weather conditions, traffic in a supermarket, type of foods being chilled…etc. A frequency drive will constantly monitor the conditions inside the cabinet and adjust the refrigeration capacity according to the refrigeration load required, rather than having the compressor’s output be at 100% regardless of the actual conditions. Benefits of Variable Frequency Drives:

  • 25% or more energy efficiency.
  • Reduced Mechanical Load on the compressor for longer service life.
  • No high energy, high wear start/stop operation.
  • Maintains optimum machine pressures & working conditions.
  • Reduce the noise levels of the condensing unit.

Electronic Expansions Valves (EEV):

Electronic Expansion Valves

    Expansion valves are devices that are used to reduce the pressure of the liquid refrigerant to allow it to change form from liquid to gas at the inlet of the evaporator. Electronic expansion valves are a development of the thermal expansion valves that have traditionally been used, and their benefits are:

  • Adaptive Condensing temperature increases Annual savings up to 30%.

Explanation: When using a thermal expansion valve, there is only an open/close mode for a set period of pre-determined time regardless of the actual refrigeration required, condensing pressure will remain constant regardless of the load. When using the electronic expansion valve, the duration of the opening of the valve is determined according to the refrigeration capacity required, if the capacity required is low, the volume of gas passed through the valve will also be low, the condensing pressure will be adjusted accordingly.

  • Savings from a lower suction pressure and improved compressor efficiency.
  • Efficient utilisation of the evaporator in all conditions.
EC Fan

Electronically Commutated Fans (EC):

EC fans are fans with brushless DC motors, and their speed can be adjusted according to the demand needed. Traditionally, fans are switched on and off, on when cooling is needed, and they are turned off when the cooling is done, the speed will remain always constant regardless of the need. This is very wasteful, the higher the speed, the higher the power input and when it is not needed, the extra power will be converted to heat, which is not used and has to be accounted for in the cooling load of a particular refrigeration system. With EC fans, as the speed is constantly adjusted according to the output needed at any given moment. When that is the case, the heat generated by the fans is minimal.