Don't really notice any difference, but would rather have them than not. Any setting above low very noisy.

I have three sets of Hunter air purifers and they are great and I have allergies and asthma. Once I arrange and plae them properly in my home having relief for allergies and dust pollen set asthma attacks. I had Hunter air purifers for years and I gave to my son and family and they are still operating. I would recommend these sets, I also like it when they had large size for larger room that what I had B/4. Thank you, Memaw9

These purifiers worked very well however the cost of the replacement filters far exceeded the benefit of keeping the product, especially when there are other products on the market that have zero cost for upkeep!

Only had this for a week and it works great. My house mate smokes so I have it in my room to filter the air on Medium and it works thanks Hunter. form a none smoker.

I was looking for product with ionizer. I have clean air. I leave in apartment. No more cooking smell. Thanks HSN great product . Kill all bad odors. I recomend Hepa Air Purifiers.