This product works efficiently . I cannot say it improves asthma as about a week after using the product our family had a asthma “flare up” I call it . Just continuous asthma issues which is typical for us this time of year so on that aspect I wouldn’t say it improves it . However the air smells cleaner and it has a small reduction in dust accumulation . Anytime our pets walk past it shows red for poor air quality and kicks in and cleans the air quickly .