June 16, 2010
New Labeling System of Grading for Windows to be Noticed

METI announced the amendment of “the Labeling System of Grading on Thermal Insulation Performance for Windows” on May 24, 2010. Under the current business practices, the openings are divided into 3 types; windows, glass and sashes. However, in the Amendment, they will be indicated just as “windows,” and below is a new labeling.
The System is going to become effect on April 1, 2011.

Coefficient of Overall Heat TransmissioniW/m2₯Kj Indication of Grading
2.33 or lower šššš
2.33 ` 3.49 ššš
3.49 ` 4.65 šš
4.65 or higher š

Coefficient of Overall Heat Transmission:
In case of that the indoor-outdoor temperature differential is 1℃, it is the value of the heat quantity of convection per 1m2, indicated in Watt. A smaller value means a better thermal insulation performance.