In many commercial buildings it has become common to have a dedicated 100% outside air system to supplement the primary systems across zones. Modelling this in EnergyGauge Summit however is not always perfectly clear or easy to do because of the one system per zone limitation. There are one of two suggested methods for showing compliance on this additional system. 

1. The first method for modeling the system and showing compliance accurately is to combine the system with a system of the same type. When doing this it is important to note that they must be the same type and near enough the same capacities that they both fall under the same minimum efficiency requirements. For example an air cooled split system of 60,000 Btu/h and a same type system of 50,000 Btu/h both have a SEER min of 13 but a system of 60,000 Btu/h and a system of 70,000 Btu/h have two different SEER requirements and will not work here. (As of 2010 Florida Code) If both systems do have the same requirements however than you can combine the total capacities and perform a weighted average of the efficiency to show compliance accurately. You will have to justify these numbers when submitting forms. 

2. The second method for modeling the system and showing compliance accurately is to split the zone in two, and assign the two systems serving the space each one half of the zone. This method requires no explanation to building officials, and thus reduces your need to further elaborate on these numbers when submitting forms.