The Reznor® model RBL is a packaged air handling unit, consisting of a blower/filter cabinet and twin centrifugal blowers. This unit has been engineered for use with Reznor® duct furnaces when design considerations do not permit the use of a Reznor® packaged system. The cabinet is weatherized with an integral curb cap base for outdoor installation, but may also be installed indoors. The blower cabinet has a standard horizontal discharge air opening. A bottom discharge air opening is available with the addition of an optional downturn plenum. The blower cabinet has a standard horizontal inlet but is engineered to allow for the standard horizontal and/or an optional bottom air inlet with various optional damper control systems. To obtain the desired CFM, a selection of motor and drive combinations are available.