Room air conditioners were part of the 9 products category in the initial top runner program.
Since the most energy efficient product on the market during the standard-setting process set the Top Runner Standards, the standards are based on market data. But, the Program also takes into consideration technological analysis, i.e. Top Runner considers technological potential for efficiency improvements in the future. For example, the Top Runner Standards for room air
conditioners smaller than 4 kW for 2010 were defined as a 3 to 4% improvement over the Top Runner products in 2005 as such technological improvement was assessed to be feasible by stakeholders’ discussions in the Air Conditioner Evaluation Standard Subcommittee.
Another important feature of Top Runner is that standards are differentiated based on various parameters. While it seems quite reasonable to differentiate the standards based on size and weight, technology type is also considered in the categorization.
In order to comply with the standards, producers must make sure that the weighted average efficiency of the products they sell in a target year achieves the standards. Therefore not all of a manufacturer’s products have to meet the target, but the average of all products has to. This flexibility enables producers to provide a wide range of models to meet the market demand while guiding the overall market to higher energy efficiency.
In sum, the major characteristics of the Top Runner approach can be described as:
- the Top Runners set the standard, with consideration of future potential improvements;
- differentiated standards are set based on a range of parameters;
- compliance with the standard is evaluated by corporate average product sales
source: Kimura Osamu, The role of standards: the Japanese top runner program for end-use efficiency