HAM: GLASTA

http://www.physibel.be/V0N2GL.HTM

Description of the program GLASTA allows to calculate heat and vapour transfer through a plane multi-layered construction.

The program checks if condensation occurs for a series of steady state boundary conditions at both sides of the wall. Not only the method of Glaser is used, but also the capillary water distribution in the layers is simulated. In this way GLASTA is appropriate not only to check condensation but also to simulate drying.

Input data

wall description: surface heat transfer coefficients, surface thermal resistances, surface equivalent diffusion thicknesses; for each wall layer: material name, thickness, thermal conductivity, thermal resistance, vapour resistance factor, equivalent diffusion thickness, and for the extended Glaser method: possibility for humidification by interstitial condensation, critical, maximal and initial water contents,

climate description: number of cycles (typically a year) and for each period (typically a month, max. 48 periods): name, duration, environmental temperatures, relative humidities, vapour pressures,

a database of monthly average climates for more than 100 European locations is available,

Calculation

Three different calculation methods may be used:

In the normal Glaser method, the temperature, the saturation vapour pressure, the vapour pressure and the vapour fluxes in interfaces and layers are calculated for each period. Condensation or drying occurs when a discontinuity occurs in these fluxes. The interface water contents changes by the amount of condensation or drying. The method is in accordance to the prEN ISO 13788,

DIN Glaser method: a small constant quantity of water is assumed in the interface in which the most important condensation occurs; the resulting ratio drying/condensation corresponds to the DIN 4108-standard,

extended Glaser method: not only the material interfaces but also the layers themselves can contain water; the critical water contents and the initial water contents play an essential role in the calculation.

Alphanumeric Output

tables of the construction and climate data,

Glaser tables for the periods considered,

tables with condensation and drying amounts during successive periods,

summary of results.

Graphic Output

Wall section,

Climate graphs,

Glaser diagram per period,

Animation file (avi) of Glaser diagrams for the whole period,

Moisture distribution diagram,

Water contents evolution.

Glasta version 5.0w new program performances

Developed for Windows 95/98, Windows NT,

Wall section preview during data selection,

Climate graph preview during data selection,

Built-in file converter for data of previous GLASTA versions,

Preview material properties during selection,

Built-in report generator in Word format,

Create animations of successive Glaser diagrams,

Switch easily between the languages available (English, Dutch, French, German),

Create bitmaps in high resolution,

Real time calculation provides immediate results,

Extensive wall editor functions,

Extensive climate editor functions,

Project files collect all input data,

Improved and extensive material patterns.


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