Defrost airflow assembly for a heating, ventilation, and air-conditioning (hvac) case

A heating, ventilation, and air-conditioning (HVAC) case, comprising

• a housing and
• a defrost airflow assembly including:
• a first defrost channel starting in a mixing chamber and terminating in a first defrost outlet with a first defrost door movable between an open position and a closed position so as to sealingly divide the defrost channel into a pre-door first defrost channel and a post-door first defrost channel;
• a first demist channel starting in the mixing chamber and terminating in a first demist outlet with a first demist door movable between an open position to a closed position so as to sealingly divide the first demist channel into a pre-door first demist channel and a post-door first demist channel;
• a first bypass channel connected directly with the pre-door first defrost channel, the post-door first defrost channel, the pre-door first demist channel and post-door first demist channel;
• wherein the first bypass channel is configured to allow airflow from the mixing chamber to the first defrost outlet when the first defrost door is in the closed position and the first demist door is in the open position.