An economizer for an air handler, air conditioner or similar unit. The economizer has a first position and a second position. In the first position, the economizer is retracted and presents a relatively flat end surface of the air handler, and in a second position the economizer projects from the air handler and provides for the intake of ambient air into the air handler. The invention provides for the shipment of the economizer intact with the air handler so that installation of the unit is conveniently achieved.