BIM & building simulation

Over the last three years the understanding, adoption and use of BIM has gained international momentum.

Retro-commissioning of a heat source system in a district heating and cooling system

To improve the energy performance of a district heating and cooling (DHC) plant, the expected performance of the plant was studied using simulations based on mathematical models. A model of the entire heat source system with an embedded module that automatically determines the on/off status of heat source equipment using cooling/heating loads was developed and validated using measured actual performance data. The mean error between the simulated and measured total energy consumption was 4.2%.

Modeling and experiment analysis of variable refrigerant flow air-conditioning systems

This study developed a component-based gray-box model for variable refrigerant flow (VRF) airconditioning systems to simulate and predict the performance and energy consumption of VRF system in cooling condition. Results from the testing of Daikin’s 10HP VRV system with six indoor units, as well as the manufacturer’s data, were used to fit the key parameters of each component in this VRF model. This model was integrated in the building energy simulation software DeST and was validated by using data both from Daikin’s product handbook and from tested results.

Impact of window design variants on lighting and cooling loads: clues for revisiting local building regulations

The study is placed within the context of local building regulations in India. Building regulations, for fenestration in general and window openings in particular, are, to a large extent, ambiguous in nature. In the context of India, observations show that the regulations specify window size for the sole purpose of ventilation whereas windows are major roleplayers in the thermal and daylighting performance of buildings.

Faces (forecasts of air-conditioning system’s energy, environmental, and economical performance by simulation)

FACES is a simulation tool for selecting an appropriate heat source system in the early building design stage. Heat source systems have to be studied at an early design stage, because they are closely related to the floor plan. However, in an early design stage, most  of the problems are unsolved, so that there is insufficient data for system simulations. In order to enable detailed and accurate studies for various kinds of buildings and heat source systems,  FACES utilizes full-scale programs for heat load calculation and system simulations.

Development of HVAC system simulation tool for cycle energy management- Part 3:case studies using developed tool on each phase of life cycle

The HVAC system in a real building was simulated by the energy simulation tool being developed (Ito et al. 2007, Sugihara et al. 2007). In order to confirm the practical utility of the tool, the studies are conducted on each phase: Program/Planning/ Design  phase, Construction phase, Pilot-Operation phase and Operation phase.

Development of HVAC system simulation tool for life cycle energy management- Part 2: development of component models for HVAC equipment

This paper describes the conversion of equipment characteristics into mathematical formulae, verification of the precision of said mathematical formula, and a concrete simulation tool. The main feature of this simulator is that operation of equipment is solved using temperature and flow, not calories. However, the characteristics of equipment are described using as simple a formula as possible. These formula are verified with actual values, and the simulator was confirmed to provide sufficient accuracy for energy management.

Development of HVAC system simulation tool for life cycle energy management- Part 1: outline of the developed simulation tool for life cycle energy management

The importance of LCEM (Life Cycle Energy Management) has been recognized from the view of life cycle energy saving of sustainable buildings. The purposes of this research are proposal of an LCEM framework and development of prototype HVAC system simulation tools for LCEM. In this paper, necessity of energy simulation tools for LCEM is discussed, and the outline and solution method of the simulation tool are shown.

The energy consumption of the public buildings in Osaka, Japan

The aim of this research work is to investigate the actual energy consumption in existing public buildings and to obtain the basic data for energy conservation of these buildings. Various monthly energy consumption data of public buildings in Osaka for the period from April 2000 to March 2002 was gathered and analyzed to determine the nature of the energy consumption of buildings. One of the investigated buildings is selected as the typical building and the heat load is calculated. The calculated values of the energy consumption are compared with the investigation values.

Application of modeling and simulation in fault detection and diagnosis of HVAC systems

Failures can lead to a series of problems in the complex heating, ventilation and air-conditioning (HVAC) systems in buildings. Fault detection and diagnosis (FDD) is an important technology to solve these problems. Models can represent the behaviors of the HVAC systems, and FDD can be realized with models. Using the model as intermediary, a link between system simulation and FDD can be built. Simulation has provided a convenient platform of operation for FDD, the overall simulation methodology in FDD of HVAC systems is briefly introduced.