Solar reflective coating on position 2 & 3.

 As we know,soft coated low-E coatings must be made into insulated glass,on glass surface #2 ,or surface #,for laminated insulated glass,the coating will be on surface #4,or #5.The main affected glass performance is the solar coefficient,and U value.Compared with low-E coating on exterior glass, coating on interior surface will have higher solar coefficient,suitable for high altitude areas that require more solar energy.

But for solar reflective glass,as there’s no silver layers in the coating,it can be used in both interior and exterior glass,so will this affect the glass performance?

Firstly,customers should be aware that ,the solar reflective glass will have some reflective color,usually blue,blue grey,silver grey color,when placed on the insulated glass interior panels,the reflected color is different from the color on exterior panels.This problem also happened to low-E coatings,especially for double silver low-E,the front side of double silver low-E coating are usually blue,while the back side are sometimes purple,red,green colors,this will affect the overall building appearance,please double confirm before confirming the coating position.

Glass spandrel glass,solar reflective glass

Secondly,how the coating position affect the glass performance?

Here is an example based on Saint Gobain Solar reflective coatings:

Glass Combination	LT %	LR%	Tsol %	U -Summer	U-Winter	SC
6 ST120 #1+12A+6C	19	32	29	2.69	2.69	0.28
6 ST120 #2+12A+6C	19	26	14	2.82	2.7	0.28
6C+12A+6 ST120 #3	19	33	26	2.68	2.57	0.50
6C+12A+6 ST120 #4	19	28	32	2.69	2.55	0.49

 

Glass Combination	LT %	LR%	Tsol %	U -Summer	U-Winter	SC
6 ST150 #1+12A+6C	46	19	37	2.84	2.70	0.54
6 ST150 #2+12A+6C	46	20	37	2.84	2.71	0.54
6C+12A+6 ST150 #3	46	21	37	2.84	2.70	0.66
6C+12A+6 ST150 #4	46	22	36	2.84	2.71	0.68

Based on above glass performance data,light transmittance,light reflectance,solar transmittance,U value are not affected by the coating position,the only difference is the Solar coefficient,lower transmittance solar reflective coatings will have much higher SC value when placed on interior glass,whether it’s on surface 3  or surface 4.

Conslusion: Same as low-E coatings,when placing the solar reflective coating on surface #3,the SC value will be much higher than on position 2.Even if placed on surface #4, the SC will be same as surface 3,also very high.

Now solar reflective coated glass is rarely used ,many glass contractors and designers is using same IGU with ceramic frit on the spandrel areas,solar reflective glass is almost been forgot because its solar and thermal insulation performance is not as good as insulated glass.But in some areas,solar reflective glass,especially hard coated solar reflective glass with low light transmittance and low SC value.

Morn is your turnkey architectural glass manufacturer and supplier in China,welcome contact us if any solar reflective glass is required in your esteemed projects.

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