E38: Higher Efficiency Refrigerated Cases

Requirement Summary

This measure can be claimed if the refrigerated cases, and any other fridge or refrigerator installed are energy efficient. This can be demonstrated by purchasing refrigerated cases, fridges and refrigerators that achieve recognized appliance ratings as described in the Approach/Methodologies section (below).

Intention

Minimize the energy consumed by refrigeration equipment installed in the buildings, such as supermarkets and small food retail, to reduce the operational costs and increase the reputation of the retailer.

Approach/Methodologies

EDGE uses the following recognized appliance rating systems, but is not limited to:

• Energy Star rated - Commercial Food Service (CFS) equipment, which are up to 40% more efficient than standard ones; or
• Minimum ‘A’ rating under the EU Energy Efficiency Labelling Scheme; which will be mandatory in 2016 for commercial refrigeration cabinets (draft versions are currently available); or 
• Listed in the Energy Technology Product List (ETL); or
• Equivalent level in a comparable rating scheme to the ones above.

The energy chart shows reduction in ‘Refrigeration'.

Potential Technologies/Strategies

Refrigerated cases are mostly used in supermarkets and small food retail, where up to half of the energy consumption is dedicated to the refrigeration systems (display cases and storage coolers). Four main categories of refrigerated cases are shown in the table below:

Table 50: Types of refrigerated cases

The energy use of the cases described above is related to the refrigeration load, the sources of which are: 

• Infiltration: Moist and warm air from the ambient pass through the open front of the cases. Energy efficiency measures (EEMs) include air curtains or glass doors, which are detailed in Table 51;
• Conduction: Case panels and walls allow heat to be conducted to the interior of the case; 
• Thermal radiation from the ambient surfaces to the product and display case interior; and 
• Internal heat gains: generated by the lights, evaporator fans, periodic defrosts, and anti-sweat heaters.

To reduce this load various energy efficiency measures (EEMs) could be applied to the refrigerated cases, which result in the reduction of the refrigeration load and therefore energy savings of the retail units. These EEMs are explained in the table below:

Table 51: Efficiency measures for Refrigerated cases

Technologies/Controls	Potential Saving (Refrigeration) Energy	Application	Benefits/Key Features for Efficiency
Glass doors	Up to 50%	Chilled and frozen multi-decks	Better performance to medium temperature cases. Special Polymer doors reduce the need for thermal glass.
Strip Curtains & Air Curtains	30%	Chilled multidecks Well freezers	Reduced infiltration of ambient air and humidity into the display case.
Night blinds or Night covers	20%	Chilled multidecks Well freezers	Out-of-hours usage to reduce heat gain from ambient temperature
Multideck Air Curtain Optimization Technology	17%	Chilled multidecks	Cost savings from reduced energy consumption  Low cost and fast payback within two years  Easy to install and minimal maintenance  Warmer shopping aisles for improved consumer experience
Defrost Optimization	20%	Freezers	Need of defrost controls that triggers defrost only when needed
Interior Lighting	5-12%	All types	Energy-efficient lights: LED lighting or T8 lamps  Electronic Ballasts
Efficient Modular/Multi Evaporator Coil	10%	All cabinets Mainly freezers	Defrost system to be installed with multi-evaporator  Enhance heat transfer  Evaporator coil to operate at a close temperature difference (TD).  Efficient coil: evaporation occurs over the greatest length of coil tubing, which maintains a reasonable evaporator size.  Use of electronic expansion valves.
High Efficiency Compressors and Fans (Evaporator or Motors)	9%	All cabinets with forced air convection	Reduce both refrigeration load and direct energy consumption, as coil defrost is less needed.  Use of electronically commutated motor (ECM)  Use of variable-speed drive (VSD), which enables the coil to be held constant throughout the time between defrosts, and to reduce defrost time/cycle.
Electronic Commutated Motors (ECM)	2-8%	Evaporator: All cabinets with forced air convection Condenser: All integrals and remote system	2% for reach-in freezers  7% for reach-in refrigerators  8% for (grocery) display cases
Thicker Insulation	4-6%	All - primarily frozen	Insulation such as Vacuum Insulated Panels (VIPs) helps cut conduction heating of the cases.
Non-Electric Anti-sweat Heater Controls	3-6%	Freezers cabinets	Reduce energy consumption as load is decreased.
High efficiency Liquid Suction Heat Exchanger (LSHX)	3%	All Cabinets	Provides sub-cooling of liquid refrigerant through useful superheat.  Allows the evaporator coil to operate with low superheat at the evaporator outlet.
Tangential fan	2%	All cabinets with fans	Improve the coil airflow distribution. For increased savings to be used ECM motor and VSD controller
Low-E / reflective glazing (K glass)	1%	Glazed and delicatessen cabinets	Reduction on radiant heat

The way the occupants / building manager use the appliances also influences energy performance. It is important to provide users with guidelines outlining the benefits of these appliances, and the best way to achieve maximum efficiency.

Relationship to Other Measures

Claiming this measure reduces energy use for refrigeration only.

Assumptions

The base case assumes standard refrigerated cases. The improved case is 10% more efficient. The reduction varies depending on the type of building.

Compliance Guidance

Design Stage

Post-Construction Stage

At the design stage one of the following must be used to demonstrate compliance:  Summary list of the refrigerated cases to be installed in the building, including quantity, energy use, and proof of certification by Energy Star, EU Energy Efficiency Labeling Scheme, Energy Technology Product List (ETL), or equivalent; and Specifications from the manufactured detailing energy use.

At the post-construction stage one of the following must be used to demonstrate compliance:  Updated summary list of the refrigerated cases installed in the building, including quantity, manufacturer, and model; and  Proof of certification by Energy Star, EU Energy Efficiency Labeling Scheme, Energy Technology Product List (ETL), or equivalent; and  Specifications from the manufactured detailing energy use.

© Copyright 2020 GBCI. All Rights Reserved.