AnTherm Documentation Update

The software AnTherm is equipped with extensive Help and Documentation. AnTherm-Blog offers supplemental information. Picture gallery (Picasa) and Video gallery (YouTube) provide visual impression.
This documentation is not only included with the program's installation but it can be also viewed on internet.

We've made efforts to provide documentation suitable for every user - an engineer, architect or student - making the starting the use of an application as easy as possible. Theoretical background of building physics and engineering calculations, used algorithms and procedures but also normative information have found their way into the documentation.

Extensive tutorials enable an easy start for new user leading him through a calculation of a two dimensional and then three dimensional thermal bridge component. The study of examples provides a quick overview of major application's functions. We've selected few common construction components for chosen  simulations and thermal heat/cold bridge analyses. Evaluations of heat stream (heat flux) lines, temperature on component's surfaces or throughout an interior of construction or even evaluations of condensing humidity (dew point) to answer the question about the risk of mould growth have been considered in examples chosen.

• Complete application's documentation (HTML, requires HTML-Help navigation component and JavaScript within your browser)
• Complete application's documentation (HTML, without navigational elements)
• The Handbook as PDF-File (9,78 MBytes) Note: Version 6.114 to 8.131 - current version available as HTML above
• Demonstrational videos and examples of results
• Further pictures and examples
   
• Tutorials / Cook-Books
• FAQ (Frequently Asked Questions)

What is the "HARMONIC" Option of AnTherm

The HARMONIC option of AnTherm calculates “harmonic thermal conductivities” of component or building as indicators required for transient building energy simulations based on periodic (harmonic) approach. This also includes PHPP calculations.
Thermal Harmonic Conductivities and further dynamic indicators facilitating heat transport with heat capacity capabilities follow the ISO and EN standard EN ISO 13786.

The harmonic thermal conductivity is given by the amplitude and phase lag of the heat flow which follows periodically changing boundary conditions (either temperatures or heat sources or sinks). Lagging in time with damping of amplitude (attenuation) results from heat storage capability of materials.
Heat losses might lag many months, intermittent heat gains might result also. Cooling infrastructure might become obsolete or overheating can be practically resolved with the building own (heat) capacity.
Transient heat flows are heavily dependent on heat capacity of building components, especially massive, solid or brick walls, slab or ground structures.

The Harmonic option of AnTherm can be seen as a small brother of the much more extensive TRANSIENT-Option of AnTherm.
The purpose of the Harmonic option is to solve transient, periodic heat transmission equation for the 0-th and 1-st harmonic. The 0-th harmonic is the steady state solution of the equation corresponding to mean heat flows under periodic boundary conditions. The 1-st harmonic provides solutions of amplitude and phase lag for the main period, such as day or year.
When power sources are involved AnTherm’s Harmonic option reports Harmonic Heat Distribution Factors (additionally to Harmonic Thermal Conductivities reported for spaces) and are also given by their amplitude and phase lag of the heat flow following the oscillation of respective heat source or sink.

By using the harmonic indicators much better approximation of dynamic thermal behavior of the building can be obtained when compared to simplified steady state approach – even with only one first harmonic of the oscillation.

Exact indicators calculated with AnTherm for any 3 dimensional geometry and arbitrary combination of materials are indispensible replacement for approximations restricted to few simplified geometries only as those provided in ISO 13370.

The strength of the HARMONIC tool relies on the fact, that harmonic thermal conductances (complex number, amplitude and the phase lag) can be calculated without the need to enter nor to know any boundary conditions – harmonic thermal conductances are output just following the steady state thermal conductances L2D, L3D in the respective report. There is also no need to specify or assume any starting boundary conditions as compared to time step based methods.

It is very important to emphasize, that harmonic thermal conductance are characteristic for the object concerned and by that are independent of any boundary conditions. The proper calculation of these harmonic periodic indicators does not need to know nor to apply any boundary conditions. Further evaluation of the behavior of a building component under certain and periodically changing boundary conditions is subject to the “TRANSIENT” Option of AnTherm (higher harmonics, periodic boundary conditions, animation in time and timeline outputs).

The concept of harmonic thermal conductances

The concept of harmonic thermal conductances is very well suited for modelling dynamic thermal behaviour under periodic boundary conditions. A method for implementing such a model in simulation software is proposed and compared to simplified methods currently employed in international norms and standards. The practicality and efficiency of the harmonic approach is demonstrated using an appropriate simulation software package (“AnTherm”), which allows the three-dimensional, time-dependant visualisation of simulation results. In conclusion, arguments for specific future developments are presented, including the potential for model translation into 4D-enabled virtual environments.

The paper "Practical implementation of a harmonic conductance model
in thermal simulation software" has been presented lately during the 9^th Nordic Symposium on Building Physics held in Tampere (Finland) from 29^th May till 2^nd June 2011.
Read more at the AnTherm's website...

Transient thermal bridge calculation in AnTherm

As of today AnTherm will be available with transient (periodic, harmonic) calculation of thermal bridge indicators soon. The new release, calculating dynamic harmonic thermal conductance and phase shift will be released soon. These characteristic harmonic indicators are calculated without any need of boundary conditions thus simplifying the process of thermal bridge analysis significantly.


GA availability of HARMONIC option is expected by February 2010.

This new release will shift AnTherm to the next level and make it the only tool available for direct stationary and transient state 3D calculations to civil engineering and building experts on supported platform.