Air Purifiers

http://www.sharperimage.com/us/en/catalog/product/product__SI995YYY/sku__SI995YYY

that is what I’m about to purchase - any recommendations?
I have severe dust allergies (sorry that got cut off). I have SEVERE dust and asthma - I need clean air. I clean like a nut but nothing really helps.

My brother has severe dust allergies. I am wondering if this product might be a good one to talk to him about.

I have tried everything, encassings, keeping area clean….nothing works. Whats the best air purifier for these terrible dust allergies?

I try vaccuming too but it seems to kick up the dust and make it worse.