Is solar control PVB film really effective in laminated glass?
Solar control PVB film is used to reduce the solar energy that transmitted the laminated glass.Same as normal PVB film ,solar control PVB film specifications, laminating workmanship is exactly same as normal PVB film.
Solutia SG41/SH41 are solar control film produced by Eastman,L-SEC SCF301 and SCF 307 are products of Sekisui. Here we study the film and see if these solar control film is really effective when been applied in laminated glass.
Firstly let’s see why Solutia develop solar control PVB film-SG41:
Energy awareness driving market
High demand for solar control laminated glass
Complex laminating technics for coated glass
Saflex ® SG solar interlayer is a high visible light, solar absorbing technology designed to enhance solar heat gain performance as compared to monolithic clear glass and laminates made with standard clear polyvinyl butyral (PVB) interlayer.
I believe that many architects and designers are easily been persuaded by their sales to change to using solar control film instead of normal PVB film in laminated glass,but how much solar energy can be blocked or absorbed ?How energy efficient is the solar control film? Below chart may help you understand.
The chart contain 6 different glass combinations including 2 S-LEC solar control film, 2 Solutia solar control film,clear laminated glass with normal PVB ,and laminated glass with hard coated low-E.
1.Light transmittance:As we can see compared with normal clear laminated glass,all other 5 options LT is lower but keep over 70% which offers good visible light transmittance.
Compared with normal lami glass, solar control film have relatively lower solar energy direct transmittance,and Solutia ones is much better.The best one SG41 reduce 32% solar energy transmittance.
3.U value: As we know U value means the glass heat conduction,the lower U value,the lower heat conduction through glass.All solar control film keeps same value as normal clear,it won’t reduce the energy through the glass.
4.SC value:SC value means the enegy pass the glass,the lower,the better.S-LEC SCF301,SCF307,Solutia SG41,SH41 decreased 9%,21%,31%,20% solar energy.
With above info,we can see solar control film does decrease certain solar energy,from 10% to 30%,but compared with hard coated low-E glass,they have similar LT,SC value,while hard coated low-E product has 50% lower U value.
Then now the cost:S-LEC SCF301-USD20/SQM, SCF307-USD35/SQM, Solutia SG41 USD30/SQM.
Hard coated low-E price is only USD2/SQM higher than normal clear glass.Hard coated low-E has the best costs performance.
Solar control film can reduce solar energy ,but overall performance is worse than hard coated low-E whose costs is only 10% of solar control film.
It’s unwise and not recommended to use solar control film in your laminated glass,if you really want to make your laminated glass energy efficient,please consider cheaper and better performance hard coated low-E products.
Morn is your turnkey China laminated glass supplier,welcome contact us and let’s work on your next great project.