A conditioned air blower system for ventilating a trailer interior includes a centrifugal blower and a heat exchange unit. The centrifugal blower includes a blower housing, an inlet portion configured to direct air into the blower housing, and a discharge portion configured to direct air from the blower housing into the trailer interior. The heat exchange unit includes an air inlet portion, heat exchange elements, and a conditioned air exit portion coupled to the inlet portion of the centrifugal blower. The heat exchange unit conditions ambient air introduced at the air inlet portion from a first temperature to a second temperature by heat exchange relationship with the heat exchange elements. The conditioned air blower system may include a controller operatively associated with the centrifugal blower. The controller monitors a condition related to the centrifugal blower, and regulates the supply of temperature-conditioned air in response to the condition.