All Flare Fireplaces require a heat release
The heat release is an air outlet that helps relieve radiant heat created by the top of the fireplace. The heat collects in the fireplace chase and, through natural convection, rises up and out of the release opening. The heat release outlet for hot airflow from the wall enclosure must remain open. The outlet must be at the top of the enclosure, but not necessarily at the front, and maintain certain minimum measurements relative to the size of the fireplace. The opening can be installed at the sides of the enclosure (to the left and right of the framing) or back or on top of (in case of a drop wall or shadow line design). Depending on the unit size and BTU the heat can be up to 180 degrees fahrenheit.
For fireplaces sized 80”- 100″ / 200 cm – 250 cm – Heat release area must be at least 200 square inches.
For fireplaces sized 60”-70″ / 150 cm – 175 cm – Heat release area must be at least 140 square inches.
For fireplace sized 50” / 125 cm and smaller – Heat release area must be at least 100 square inches.
The heat release(s) must be at least 1” (25mm) from the ceiling and no more than 3” (76mm) down. Install the vent on top of the enclosure with a drop wall or shadow line (a chase that is not built all the way to the ceiling). Preventing you from placing a heat register in the middle of the finishing material.
Install Manual Reference: Page 74