With the relationship of thermal comfort index and properties of glass windows and glass windows with films as shown in Figs. 20 and 21, one can find the total thermal comfort index (state of discomfort) for any types of glass windows and glass windows with films under Thailand design weather condition for the purpose of the performance rating to choose the proper glass windows and glass windows with films in aspect of thermal comfort.
For the heat transmission study, the relationship between the heat transmission index (relative heat gain) and the properties of the glass windows and glass windows with films can be obtained and displayed in Figs. 22 and 23. Fig. 22 shows the relationship between the relative heat gain values and the total transmittance of the glass windows and glass windows with films. Fig. 23 shows the relationship between the relative heat gain and the total absorptance of the glass windows and glass windows with films. One can conclude that the heat transmission through the glass windows and glass windows with films is primarily dependent on the total transmittance of the windows. The glass windows and glass windows with films with larger values of the total transmittance shall have the larger values of heat transmission. And in Fig. 23, one can see that for most of the single and double glasses with and without films which do not have special characteristics in high reflectances shall have the relationship of heat transmission index values and the total absorptance in a linear fashion with negative slope. That means glass windows with high transmittance and low absorptance values shall have heat transmission more than glass windows with low transmittance and high absorptance values. While the relationship of the heat transmission index of the reflective glass windows with the total transmittance and absorptance values are not quite unique. Since the properties that have the major effect on thermal performance of the reflective glass windows is the reflectance.