Anyone have recommendations for designs for homemade units to filter dust from the air in a room? - an ordinary room in a house, not a shop.

I've used the cannister type units with HEPA filters and a fan that sit on the floor. The do remove the visible particles of dust from the air, but I find they make the air quality worse in my less than spic-and-span home. I think this is because the normal circulation of air lets dust to settle out on the floor. The canister units suck air from the floor and shoot it upward. Many canister units develop vibration noises and I don't need the unit to serve as a fan. Perhaps the modest circulation provided by a small fan, like an AC version of the fans on computers, would be enough to gradually filter air.