In order to promote energy conservation, the building owner shows the understanding of the energy-saving efforts, the designer is committed to energy-saving design of the building, and government has a role to review the precise energy-saving buildings. BEST is a building energy-saving simulation program that’s been developed since 2005, as a suitable software in order to promote energy conservation. It is a life-cycle design software that can be utilized in the design and operation phase as well as corresponding to the energy conservation law. BEST is used as a simulation software that corresponds to Japan's Energy Conservation Law from 2009.

One of the factors for obsoleting a simulation tool is not updating the Equipment Characteristics after the release of the program. For this reason the BEST (Building Energy Simulation Tool) program committee, the section meetings for Equipment Characteristics are held continuously and the BEST program’ Equipment Characteristics is updated frequently. The section meetings are held among the type of equipment, and there are cooperation agreements of Industry Association at the section meetings. The Equipment Characteristics’ databases are made up of two models (statistical model and physical model), and the databases hold three datasets (rated Characteristics, mid Characteristics, dynamic characteristics).

BEST (i.e. Building Energy Simulation Tool) is a whole building energy simulation software. Its development was started by a Japanese industry-government-academia joint team in 2005. Since then, BEST has continuously been refined. This paper describes the concept and the features of the latest version of BEST relating to simulation methodology, databases and user interfaces and also presents the simulation results that shows the specific capabilities of BEST. BEST enables integrated simulations of building behavior and control operation of HVAC systems as well as electric and plumbing systems.

This paper describes simulation methodologies of HVAC systems using self-adjusting template, which are implemented in the BEST program. To achieve extensibility and ease of maintenance, modular structure is introduced. Any appliance is modeled as a module class that implements formatted common functions. One of the new features of the BEST program is “template” structure by which effort for making input data is considerably reduced. Templates are a partial systems implemented, should be prepared in advance connected parts of more than one module.

While buildings will always have unique characteristics, there are a number of strategies that can help close the gap between the expected and realized energy performance. This paper presents common issues that arise from the design phase to ongoing operation of buildings. The paper focuses on monitoring-based commissioning using real time data and advanced software analytics to uncover and resolve problems. Real world examples are presented to showcase the challenges faced with complex equipment operation. Examples of technical issues uncovered during commissioning will be provided along with solutions to reduce these issues in the future.