Dedicated outdoor air systems (DOASs) use separate equipment to condition all of the outdoor air brought into a building for ventilation, and deliver it to each occupied space, either directly or in conjunction with local or central HVAC units serving those same spaces. The local or central HVAC units are used to maintain space temperature. A DOAS unit can be simple, with just a few components (e.g., a fan and a cooling coil), or more complex, with several energy recovery devices, cooling coils, heating coils and one or more fans. Generally, the objective of a DOAS is to condition incoming outdoor air before it mixes (and is diluted) with the remainder of the building air so that it is easier to dehumidify and clean, and so that energy in outgoing air can be recovered to precondition incoming outdoor air. Applications Air Distribution Equipment Configurations Control