Refrigeration Efficiency

Refrigeration represents over 60% of the energy usage in grocery and convenience stores. Easy and affordable opportunities exist to reduce commercial refrigeration energy use, operating costs, and greenhouse gas emissions.

A refrigeration system is made up of many different components that work together to remove heat from a confined space.  Improvements can be made to each of the individual components that can help increase the efficiency of the whole system.  Common refrigeration efficiency measures are to:

• Add automatic door closers and replace gaskets.  These measures will ensure that the cold air in the refrigerated space does not escape.  With any refrigeration system, leakage problems are often the easiest and most cost-effective improvements to be made.

• Replacing existing motors with high efficiency motors.  There are several different electric motors used in a refrigeration system.  The evaporator, condenser, and compressor all use motors.  A common energy efficiency retrofit includes replacing the evaporator fan motors with high efficiency (ECM) motors.  Evaporator fan motors are often chosen because of their high run times and relatively small size.

• Install controls to moderate components.  There are a number of different controls that can be installed on a refrigeration system to increase its efficiency.  These controls can range from relatively simple (such as smart defrost, evaporator fan runtime controls) to complex (floating suction and head pressure controls).  A common energy efficiency retrofit involves installing an evaporator fan control that will allow the evaporator fans, which are inside the cold space of the refrigeration unit, to only run when needed.  In an uncontrolled system, the evaporator fans run all of the time, however the runtime can be reduced to only run when needed for heat transfer (blowing new cold air) or air circulation (circulation of existing air in the space).

• Insulate.  Just as with a building, adding insulation to a refrigeration system will reduce the amount of heat that moves through the walls from the outside of the unit to the inside.  However, adding insulation to an existing unit can be difficult because it can involve removal and rebuilding of the existing walls.

The Redwood Coast Energy Watch Small Business Direct Install Program can assist owners of commercial refrigeration units to develop plans for energy efficiency retrofits, and can provide cash incentives and retrofit project management. RCEW can provide direct rebates for certain refrigeration measures and assist in obtaining PG&E rebates for other measures.

Useful links:

• Energy Star commercial refrigerators and freezers: If your are purchasing new refrigeration equipment, an Energy Star qualified unit uses at least 15% less energy than required by current federal standards and 40% less energy than the conventional models sold in 2001.
• Flex Your Power - Commercial Product Guides: Visit this site for information on products such as glass door merchandisers, reach-in refrigerators, and solid door refrigerators and freezers. 
• Food Service Technology Center: Provides a variety of fact sheets and other publications regarding commercial refrigeration.