Never run out of filters during the season with the Aprilaire 45 replacement cool mist humidifier water panel that comes in a convenient 2-pack.
This Aprilaire humidifier pad is the key component for generating humidity in your Aprilaire 400 humidifier system. The paper filter media absorbs water from the tray while a fan pushes air across the material. This causes air to pick up moisture where it then moves around the room.
For best performance replace your filters at least 2 times a season.
Recommended Replacement: At least twice during the heating season.
Other Stock Numbers: UAPRILAIRE45O