TheFaz wrote:The height of most home ceilings is pretty standard.
I agree. And even with vaulted ceilings, I'm sure square footage is a more accurate metric anyway. Dust tends to collect on the floor, and is generated mostly by human/pet activity. Humans live within the bottom 8' of any given floor, give or take. Standard ceiling height is typically 9' or 10'. If you have higher ceilings, great, but the rest is just air up there. I doubt the top half of a tall room generates much dust. I have one room (living room) with a vaulted ceiling, and I'm not concerned at all that this unit would fail to operate just because it has more "cubic footage" in that room. I'm not a dust scientist, but I've never had to get out a ladder to dust my ceiling. :-)
Furthermore, people are familiar with square footage calculations. I know the square footage of my house, but I don't know the cubic footage. So that number would require a meaningless translation on my part. One can safely assume that the appliance manufacturer assumes you have a ceiling height within a normal range. If you happen to live in a mage tower, your mileage may vary.
I'm in for two on this deal. I've never used an air purifier before, but I'll give it a shot. I have pollen allergies in the spring, and if this helps at all I'll be happy. I also have two small kids, but I'm skeptical about the "germ killing" component of this. Even so, at $100 each these seem like a great deal for the HEPA filter component alone, and Amazon reviews tend to be reliable in my experience.