We rent a small office in Sacramento and the afternoon sun through the glass makes the front room hard to work in. Thinking about commercial window film for the whole floor. Has anyone done this for a workspace and what should I check first?

I am in a similar situation with a storefront and I have never ordered commercial tinting before, so I am trying to understand what actually matters before paying anything. Most of our glass faces west and by midday the space heats up badly, so heat reduction and UV blocking are the main reasons, with a bit of privacy as a bonus. While comparing local options I saved a page about sacramento commercial window film mostly to see how coverage and warranty terms are usually described, but I would still rather hear from people who already went through it. How do you verify that an installer is a real authorized dealer for brands like LLumar or STEK? Does a starting point around 10 per square foot look normal for this area, and how many days does a full storefront usually take?