Comparison Between Low Ironed & Tempered and Normal Ironed & Tempered Glass Efficiency Curves in Different Wavelengths

The efficiency difference between the two materials is not neglectable in the first column in which the sun is directly visible. However the main difference occurs in the third coulmn in which direct sunlight disappeared due to clouds and only infrared light can be absorbed. This significant difference can not be ignored and it is one of the most important reasons for choosing selective coated collectors.