I have asthma also. I purchased a Hepa Air Purifier several years ago, the big one capable of cleaning out 1000 or 1500 square feet. I leave it run 24/7 on low and have found that it helps IMMENSELY. I am particularly sensitive to perfume and if someone walks in the house wearing it, I turn my purifier on high. Within a few minutes the scent is gone and my asthma is back under control. It's worth every penny I spent!