A heating, ventilation, and air cooling (HVAC) assembly including a blower, an air inlet, and a movable airflow obstruction member. The air inlet is defined by a housing. The blower receives airflow passing through the air inlet. The movable airflow obstruction member is movable to: a deployed position in which the airflow obstruction member is arranged to reduce airflow volume through the air inlet a first degree; a non-deployed position in which the airflow obstruction member is arranged to not reduce airflow volume through the air inlet; and an intermediate position in which the airflow obstruction member is arranged to reduce airflow volume through the air inlet a second degree that is less than the first degree.