Terminology
What is SHGC?
SHGC — solar heat gain coefficient — is the fraction of incident solar radiation admitted through the glazing assembly, expressed between 0 and 1. Lower means less solar heat gain. It is the value used in energy modelling and frequently the one a specification calls out.
SHGC and TSER describe the same physics from opposite directions: SHGC is what gets in, TSER is what is kept out. A specification written in one should not be answered in the other without converting the comparison properly.
Applied film lowers SHGC for the assembly. How far depends on the film and the base glazing, and the resulting figure has to come from manufacturer data for that combination.
U-value is a different property entirely — it describes non-solar heat flow, and applied film has limited effect on it. That is why film is a solar instrument rather than a winter heat-loss fix.
Technical performance, service life and warranty terms come from current 3M documentation for the specific product and application. We attach those documents to proposals rather than paraphrase them.