I have an 1100 sq ft mobile home insurance office in Houston. We are located at the intersection of two busy highways, and are in a strip center, between a beauty salon and a high volume barber shop. The air quality is not that great so I run air cleaners 24/7.
We needed to replace one air cleaner and selected the Multi-Tech Intell-Pro XJ 3800 after reading some reviews and comparing prices. The XJ 3800 has a list price of $ 299 but I found one online for $ 213 delivered, including a spare HEPA filter and UV bulb.
The unit is rated for 600 sq ft but we have another brand unit running. The two units together do a very good job. The Intelli-Pro cleaner is very hi-tech and features 7 stages of air cleaning. These include a washable pre filter, washable electrostatic dust collector, activated carbon filter, HEPA filter, TiO2 filter, germicidal UV lamp, and an ionizer. This is state of the art and quite effective. The fan has 4 levels and is only slightly noisy at the highest speed. There is also an auto feature where the unit speeds up when the air is dirty and then slows when the air is cleaner. The filters have a good lifespan and the replacement cost is about $ 44 to change the HEPA filter and UV bulb. The XJ 3800 also has indicators that tell how dirty the air is, and when the individual filters need cleaning or replacement.
I think this air cleaner is a great value for a small office or for home use. The only thing I do not like about it is that cleaning and maintenance is somewhat complicated (do not discard the manual because you will need to study to maintain the unit!).