The Neutral Model Format for building simulation was proposed in 1989 as a means for documentation and exchange of models. It has attracted much interest and an acceptance as a potential standard, maintained by ASHRAE's TC 4.7 technical committee. So far, the format has only been directed towards component (leaf) models, but many suggestions have been made to extend it to also cater for systems; of component models. A brief review of NMF is given. This paper makes detailed proposals for NMF extensions covering hierarchical.
The main purpose of this paper is to develop fault detection modules for BEMS (Building Energy Management Systems), a software to aid building operators in detecting and diagnosing faults in HVAC systems. The fault detection modules proposed are based on two fundamentally different approaches based on component models: physical models and neural net-works. These modules using these mo approaches are illustrated for a cooling coil of an Air Handling Unit.
The potential of the different passive cooling strategies for popular residential buildings in Israel is evaluated using a simplified simulation program. The program, which can be run on a regular PC computer, is based on a similar one developed by the European community, but takes into account the internal mass of the building more explicitly. The passive cooling strategies considered are: natural ventilation, night cooling, ground cooling using underground pipes and combinations thereof Both air conditioned buildings and free-floating temperature buildings are considered.
There is a continuing need to validate detailed thermal simulation programs of buildings. One way of doing this is to compare program predictions with measured building performance data. This is known as empirical validation. Data from the US National Institute of Standards and Technology passive solar test facility in Gaithersburg, MD, were used to assess predictions of ESP, HTB2 and SERI-RES. The results are tested for significance by means of Monte Carlo sensitivity analysis.
The U.S. Department of Energy (DOE), through the Building Energy Tools program, sponsors development of a variety of building energy design tools from tools that analyze the properties and performance of major building components (e.g.,lighting) to tools that evaluate the energy and economic performance of whole buildings. DOE also sponsors development of new simulation approaches, validation of algorithms, and evaluation of tool performance. DOE disseminates and supports its; tools through partnerships with the private sector.
As part of a new Federal program to promote energy efficient retrofit of commercial buildings, voluntary private-sector partners evaluate potential envelope retrofits for their buildings. To support this program, we performed a series of simulations of building envelope insulation and fenestration throughout the U.S. The DOE-2.1E simulation program was used in parametric modeling of three building sizes in eight U.S. locations for thousands of combinations of loads, construction, HVAC system, insulation, and fenestration alternatives-in total, more than 20,000 envelope options.
The paper describes a component-based dynamic simulation of a variable air volume (VAV) air conditioning system. The model is based closely on the design of one floor of a real commercial office building in London. The model includes an air handling unit and a duct system incorporating pressure independent VAV boxes. The paper describes the simulation, environment used to test control systems and to develop fault; detection and diagnosis procedures and presents results of simulations that illustrate how the simulation can be used to study the interactions between control loops.
PowerDOE a new, PC-based building energy performance simulation tool, combines the full capabilities of DOE-2.IE with an easy-to-use, flexible WindowSTMgraphical user interface (GUI). PowerDOE is a collaborative effort between the U.S. Department of Energy's Lawrence Berkeley Laboratory (LBL) and the Electric Power Research Institute (EM). This paper describes the PowerDOE user interface and the methods used to unify the building description and building analysis process.
Two main modelisation techniques are the analytic and systemic methods. After a presentation of each method applied to building simulation, this paper emphases the benefit of systemic modelisation for multizone cases. Using a conceptual description of a building issued of previous method, one particular sub-system appears naturally, i.e. the thermal zone. Then, the physical coupling of thermal zones can simply be solved. Building description through data structures, required for thermal simulation, is easily reached.
TRNSYS is a modular transient system simulation program that has been commercially available since 1975. The primary use of TRNSYS is to model thermal energy systems. Although TRNSYS was originally developed for use with solar thermal applications, an effort has been made to broaden the scope of TRNSYS by increasing the number of general HVAC components and improving the usability of the building model. Some of the more recently available HVAC models include the ASHRAE Primary and Secondary Toolkits and FIVACSIM+ components.