As part of the Pure Maintenance system, an antimicrobial treatment we call EverPure is applied to every square inch of your home. One of the most important places the EverPure System treats is your air handling unit and furnace filter. As air continues to circulate through your HVAC unit, the EverPure treatment continues to make your home an increasingly healthy environment. Keep that process working by replacing your furnace filter with one that has been treated with the EverPure system.