FEDS was originally designed to model buildings with single, homogeneous heating and cooling technologies within each individual building. The portion of building set served inputs are available to specify whole buildings within a building set that are served by a given technology. If your building has more than one type of heating or cooling technology, there are a couple of options. If the majority of service is provided by one system, users might simply model that one as if it were the only system serving the building. If the occupants use portable space heaters, users could account for the energy consumed and heating service provided by representing them as a miscellaneous equipment record. If, on the other hand, one system does not dominate, it would be best to model the building as a pair of linked buildings, with one technology serving each portion. Or, if a major renovation is being contemplated, users might wish to model the building once as if it were served by one technology, and once by the other. Optimizing each case separately, the results will provide insights into which system type would be best for the building.

An option is also available that makes it possible to model multiple heating or cooling technologies serving the same building(s). To enable this feature, select the percentage of each building served option from the heating or cooling end use inputs. When this option is specified, FEDS will model the defined HVAC technologies as serving the specified portion served of each building in the building set.