In recent years, a number of developments have evolved which require improved methods for accurately predicting load profiles and energy requirements for the heating and cooling of buildings: Among these developments are modern architectural and construction practices, the increased number of energy sources used for controlling building environments, use of total energy systems, and use of computers for system control.

ASHRAE is sponsoring a two-phase program. In Phase I, four buildings were chosen for extensive study. One of these buildings is located on The Ohio State University campus and is the building which was used in this effort. Under Phase I, the environmental control system was to be simulated in order that the heat load on the building could be traced through the system and through specific pieces of equipment such as the boiler and the evaporator coils. By using the proposed load calculation technique in conjunction with the system simulation and measured weather data, the instantaneous heating or cooling loads to all zones of the building could be calculated every 15 min and the response of the system could be determined. The system should respond to the load so that there is always an energy balance between the load and the system. This in turn would allow the system energy requirements to be determined. The purpose of this effort is to develop the algorithms and computer programs for system simulation.