English

According to the Czech legislative act the operative temperature is the evaluation criterion for thermal comfort in air-conditioned or heated spaces. The operative temperature respects the air temperature; mean radiant temperature and air velocity. For mean radiant temperature calculation the surface temperature of the surrounding walls must be known. Manual calculation of the mean radiant temperature is very complicated and not suitable for practical usage since the surface temperatures are difficult to determine.

District energy systems provide commercial and residential space heating, air conditioning, domestic hot water, steam, and industrial process energy, as well as sometimes co-generating electricity in systems. Though the district energy system is usually more economical and energy-efficient than individual heating and cooling systems, it is also much more complicated system.

The directionality of light is defined as the balance between the diffuse and directional components of light within an environment. It is an indicator about the spatial distribution of light flow onto an element or into a space. This paper presents a new luminance based metric that quantifies the directionality of light. The diffuse and directional components of the luminous environment are isolated as a unique feature of simulation-based approach. The rationale and methodology of the directional-to-diffuse ratio is discussed through visual demonstrations and quantified metrics.

The airflow network model in EnergyPlus provides the ability to simulate multizone wind-driven airflows. The model is also able to simulate the impacts of forced air distribution systems, including supply and return air leaks. The air distribution system portion of the model is currently applicable for constant-air-volume systems.

In the design of indoor winter sports facilities Computational Fluid Dynamics (CFD) simulations are used to calculate the velocity and temperature distribution throughout the space, in order to complement traditional mechanical design and increase confidence into the proposed design. This process is described here using the example of a competitive curling rink. In the introduction the capabilities and limitations of CFD simulations are briefly lined out. The physics of the model of the curling venue are described.

We outline the current state of the development of a computational steering environment (CSE) for the interactive simulation and local assessment of indoor thermal comfort. The system consists of a parallel CFD kernel, a fast 3D mesh generator and a virtual reality-based visualization component. The numerical method is based on a lattice Boltzmann algorithm with extensions for simulations of turbulent convective flows.

The presented study describes a method for evaluating control strategies for shading devices.

Variable Refrigerant Volume(VRV) air-conditioning system is more liable to meet thermal environment problem than other systems such as split-type air-or window-type air-conditioner because its capacity of outdoor unit is much higher. When used in high-rise building, hot air dissipated by the outdoor units will induce buoyant airflow and increase the working temperature of units at high floor when these heat can not be dispersed in time. High working temperature could not only degrade the total efficiency, but also cause stoppage of the system.

Pressure coefficients (CP) are fundamental to calculate ventilation rates in buildings by the airflow network models (AFN). This paper deals with the use of CFD simulation to calculate Cp, and the use of those Cp values as input in building energy simulations (BES). The commercial package CFX was used to calculate CP for a 5-stories isolated building, typically found in social housing complexes in Brazil, The standard k-ε turbulence model was adopted.

In this study, the characteristics of the movement of chemical compounds in the concealed spaces and indoor spaces in houses were investigated using building cut models and a simulation program Fresh2006. The equivalent leakage areas in the concealed spaces were measured using cut models of wooden structures: a common wooden structure, an improved wooden structure and a wooden (2 inch x 4 inch) stud structure.