We understand that accurate infiltration estimation for commercial buildings is hard. The reason we have it here is that some customers focus on relatively small commercial buildings and are experienced in blower door testing and envelope measures. Those users would like to perform blower door tests on every one of their projects and they found this infiltration calc module to be very useful.
This is because when they replace each envelope component, the area is the key parameter. They know the baseline infiltration rate associated with that component from the blower door test, estimate the infiltration reduction from retrofitting that component, calculate a proposed infil rate (CFM/surface area retrofitted) and plug those numbers in OptiMiser and it calculates the savings. The CFM/surface area concept and relevant calculation fit the actual envelope retrofit process very well.
With these being said, if you don’t want to propose any infiltration reduction measure, you don’t have to input any value for base and proposed. OptiMiser can estimate energy savings based on default assumptions without any infiltration related inputs.