A modular: loop-based approach to HVAC energy simulation and its implementation in EnergyPlus

This paper presents the new EnergyPlus HVAC simulation environment, which differs from existing energy analysis programs in three key respects. First, the EnergyPlus HVAC simulation is based on a "manager-interface" protocol that supports multiple solution techniques within the overall context of the simulation. Second, the EnergyPlus HVAC simulation is based on high level component connectivity. Third, the EnergyPlus simulation and component modules enforce a high degree of data encapsulation. These three features together with input and output processing services provided by the environment result in a simulation tool that is ideally suited for collaborative development of component models, evaluation of solution techniques and design of HVAC sub-systems. The paper describes the features of the simulation environment, discusses currently implemented algorithms and includes an example of the type of results that can be expected.