Use of air conditioners inside the home or in a car can be quite helpful in reducing pollen levels. Also effective are various types of air-filtering devices made with fiberglass or electrically charged plates. These can be added to the heating and cooling systems in the home. In addition, there are portable devices that can be used in individual rooms.

Before buying a filtering device, it is wise to rent one and use it in a closed room (the bedroom, for instance) for a month or two to see whether allergy symptoms diminish. The air flow should be sufficient to exchange the air in the room five or six times per hour; therefore, the size and efficiency of the filtering device should be determined in part by the size of the room.