Freezers

Product Definition/Scope of Product Category - A freezer is a mechanically cooled device used for storing frozen food. We included only units with internal storage volumes of 7.75 cubic feet and larger, or full size units as determined by the Department of Energy.  We included both automatic and manual defrost units.

Market Segmentation - All freezers were considered as one class.

Performance Criteria - In developing the list of products that are eligible for TopTen USA we evaluated products based on the following criteria:

  • Annual energy use (kWh/yr) - This is based on average usage in typical room conditions of 70º F with door openings.

Test Methods - We used manufacturer reported test data using the following test method for measuring the performance criteria listed above:American National Standards Institute/Association of Home Appliance Manufacturers Standard HRF-1-1979, Household Refrigerators, Combination Refrigerator-Freezers and Household Freezers

Data Sources and Quality Assurance - We used manufacturer reported data from the EPA ENERGY STAR website.

Market Availability - In order to be qualified the model must be currently available to consumers through retail outlets such as department stores, big box stores, independent appliance retailers and/or on-line retailers.

Families of Similar Products - For instances in which multiple models produced by the same manufacturer (under one or more brand names) were substantially the same, we listed these products as a “tie” for one place on the list.  These instances could include models with different features or amenities (e.g., shelf configuration, color) that do not impact energy consumption or models produced by one manufacturer for sale under multiple brand names through distinct divisions of a parent company or under contract to other firms.

Product Ranking - We list products on the basis of a progressive efficiency curve, with the following equation:

Freezers: Maximum qualifying energy consumption = 25.794*Volume+23

This method helps balance the need for a range of sizes of freezers with the desire to find the lowest energy consumption. If we had simply chosen the ten lowest-energy-consuming products, they would all be the smallest size available. The coefficients in the equation were based on trial-and-error to find a regression that would include a range of product capacities. No other linear equation exists that would fulfill this criteria and also result in only 10 products.

Glossary

  • Average annual energy use - The average amount of energy (expressed in kWh) that a typical American household uses for a freezer is based on the adjusted volume of the freezer (cu. ft.)
  • Adjusted volume (AV) - A calculation of a freezer’s volume used to take into account the increased energy use of a freezer compartment relative to a fresh food compartment.  This measurement is used to calculate a freezer’s average annual energy use.

 Freezer AV = (1.73 x Total Volume)
 

  • Volume - The size of a freezer is expressed in cubic feet. 
  • Automatic defrost - An electronic control system that runs an intermittent heating cycle to prevent frost build up on the unit’s evaporator. 
  • Manual defrost - Freezers with manual defrost must be turned off intermittently in order to allow frost buildup on the evaporator to melt.
  • Progressive efficiency curve - Instead of a static efficiency threshold, the progressive efficiency curve is an equation that relates efficiency (or energy consumption) to size or volume.

Further Information -