You can add fresh air to your Breckenridge Deluxe or Premium Vent-Free Firebox. It is designed to introduce outside air to the firebox as desired. It must be installed prior to, or at the time of the firebox installation to framing. The fresh air kit must be installed prior to the installation of wallboard or other finishing materials around the unit. By adding the optional Fresh Air System, warm air blends incoming outside air to continuously freshen your indoor air. (See page 10 of the Installation Guide)