The emissivity rate is the key index to tell the advantages of off line low-E from on line low-E ref

The emissivity rate is the key index to tell the advantages of off line low-E from on line low-E reflective glass. The lower the E rate is, the more excellent the efficiency of preventing heating is. According to the national standard, the E rate of on line is below 0.25, off line is below 0.15. It is the main reason that off line low-E reflective glass is more popular in the developed countries..

Low-E Reflective Glass