Picking a great air conditioner

My favorite pizza place smells.  They make great pizza, but when I step inside, the restaurant smells slightly damp.  Thankfully, I always get my pizza to go. I remember that same smell when I was a kid, and I smelled it every time I went into the basement.  Mildew was evident down there, so my dad bought an air purifier, and it made a big difference in the basement air quality. He bought another air purifier for our living room, since we all spent a lot of time there, and he wanted the air quality to be fresh in there.  That smell in the pizza restaurant reminds me of that old basement, so I’m wondering if an air purifier can help with this issue. Since I don’t dine in, the bad air quality in the restaurant does not affect me, however, I don’t see a great many cars in the parking lot, so in a way, it does affect me.  I’m afraid that my favorite pizza joint might end up closing, since their customer base does not seem to be growing. Maybe it would, if the air quality was better. Somehow, for my own interests, at least, I must figure out how to speak to him about the bad air quality and possibly adding a purification system into the restaurant so that he can acquire more customers, and stay open.  The restaurant could probably use an updated HVAC system altogether, but if he gets an air purifier, or two, the improved air quality in the restaurant, may just mean more paying customers.