Because of the weather fastness, the low e film couldn’t be located at the external surface on the insulated glass. Normally the low e glass film is located on the inner surface of the air space, that is the #2 surface or #3 surface, #4 surface or #5 surface. But for the off-line low e glass without silver coating, or the on-line low e glass, the low e film could be located on the inner side of the room. For every air space in the insulated glass, only one low e film on the glass surface is enough. If two low e glass films are in the same air space, the energy-saving effect couldn’t be improved much. For the insulated glass with single air space, the low e film could be located on the #2 surface or on the #3 surface, but there is huge difference on the parameters of the energy saving.
When the low e film on the #2 surface or on the #3 surface, the K value or the U value is same, that means the thermal insulating property in Winter is same, no big difference. But when the low e film on the #3 surface, the shading coefficient is around 15% higher than the low e film on the #2 surface, the performance of thermal radiation resistance is worse. The followed chart can clearly show the difference of parameters for the low e glass film on different location.
For the buildings which need the good shaded effects, the low e glass film located on the #2 surface will be better, such buildings included different public buildings, the residential buildings except the severe cold regions. For the residential buildings in the severe cold regions, the requirements of getting solar energy in Winter is much higher than to have shaded effect in Summer, then the low e glass film located on the #3 surface will be suitable.
Post time: Aug-30-2022