They work!

Several family members have allergy/asthma probs and after our experience with Oreck purifiers (which didn't seem to help alleviate at all), wondered if we really would notice a difference. We ordered two, and noticed a change right away! As earlier reviewer stated, I also have to dust far less frequently than I used to before receiving this product. We don't have to take allergy-symptom meds as often either. Even overnight guests have commented on lack of normal, seasonal nasal/sinus congestion experienced while visiting.