Refrigerators and freezers are the most commonly regulated products in terms of programmes to improve energy efficiency (EE). According to a 2016 review by the International Energy Agency (IEA) they were covered by programmes that include 185 separate measures, in some 75 countries.
As a result, according to this review, the average total efficiency improvement over the last ten years of the specific products to which standards and labels have been applied in IEA member countries and key emerging economies was 16% for refrigerator-freezers.
IEC Subcommittee (SC) 59M: Performance of electrical household and similar cooling and freezing appliances, develops Standards “in the field of performance of electrical household and similar cooling and freezing appliances such as refrigerators, frozen-food storage cabinets and food freezers.” This work includes “laying down the methods of test for the” essential characteristics of such factory-assembled “appliances cooled by internal natural convection or forced air circulation.”
IEC SC 59M has published three Standards in the IEC 62552 series that deal with characteristics and test methods for household refrigerating appliances. One Standard in this series, IEC 62552-3:2015, covers “energy consumption and volume”.
It provides a method to quantify each of the relevant energy components and approaches on how these can be combined to estimate energy under different conditions.
This standard includes an annex that defines a clear and accurate method for the measurement and determination of compartment volume of household refrigerators and freezers. However, “it is not intended to provide a means of measuring the food-storage capacity, the usable volume or the usability of the volume.”
IEC SC 59M has just published IEC TR 63061:2017, Adjusted volume calculation for refrigerating appliances. This Technical Requirement (TR) aims to help define the energy efficiency of refrigerators and freezers by taking into account the concept of adjusted volume.
This approach “essentially weighs the volume of each compartment in proportion to the temperature difference between the compartment temperature and the ambient temperature outside of the appliance.”
The concept of adjusted volume is widely used and well accepted. Since there are some variations and differences in how this parameter is calculated and applied in different countries, there are anomalies in how energy efficiency parameters are calculated between countries.
The purpose of this document is therefore to encourage the use of more uniform approaches to the calculation and application of adjusted volume, where this is used in energy efficiency policies and programs.
The TR defines various terms and definitions, such as compartment, sub-compartment, compartment type, or target temperature and more. It gives details of the adjusted volume factor for various target temperatures for the different compartment types, i.e.: pantry, wine storage, chill, fresh food, zero-, one-, two-, three- and four-star.
This TR will prove a useful addition to Standards published by IEC SC 59M that aim to improve constantly the efficiency of refrigerators and freezers worldwide.