Thermal building-dynamics

Four methods for industrial air technology design are presented computational fluid dynamics (CFD), thermal building dynamics simulation, multizone... 

Four methods for industrial air technology design are presented in this chapter computational fluid dynamics (CFD), thermal building-dynamics simulation, multizone airflow models, and integrated airflow and thermal modeling. In addition to the basic physics of the problem, the methods, purpose, recommended applications, limitations, cost and effort, and examples are pro vided. 

Data from Thermal Building-Dynamics Programs... 

In many cases, some boundary conditions are not well known or not known at all. Temperature boundary conditions can be obtained from thermal building-dynamics programs that allow the capture of spatial mean temperatures during a time period as long as a whole year. Some of these programs yield surface temperature values (e.g., TRNSYS), which can be used as temperature boundary conditions at the time of CFD study. 

The main purposes of thermal building-dynamics simulation are... 

This section does not contain any fundamentals or mathematics bur tries to describe the basic energy flows and the methods used in thermal building-dynamics simulation codes to model these. Also, the methods are described without stating the underlying algorithms and equations, for which the reader is referred to the literature and references. A short outline of how these models affect the application possibilities and limits is given at the end of this section and also in Section 11.3.7. 

In thermal building-dynamics simulation codes, outdoor conditions are mostly input by the so-called weather data file, containing (usually hourly) data for air temperature, wind speed and direction, air humidity, and global and diffuse solar radiation on horizontal surfaces. 

Moisture-transport simulation includes transport as well as storage phenomena, quite similar to the thermal dynamic analysis, where heat transfer and heat storage in the building elements are modeled. The moisture content in the building construction can influence the thermal behavior, because material properties like conductance or specific heat depend on moisture content. In thermal building-dynamics simulation codes, however, these... 

Thermal building-dynamics simulation can be run basically under two different conditions ... 

The identification of zones can be made in different degrees of detail, depending on the specific purpose of thermal building-dynamics simulation. In most cases a zone can include several rooms having the same thermal conditions. Sometimes it is necessary to split a very large room into two or more thermal zones in order to have more accurate results. 

The results of thermal building-dynamics simulation are generally referred to by zone level. They can be divided into instantaneous results and summary results. 

The primary results of thermal building-dynamics simulations are hourly values of the following quantities ... 

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