Software for heat transfer and ground heat

HEAT2 - Heat transfer in two dimensions

Now supporting over 40 languages!


HEAT2 is a PC-program for two-dimensional transient and steady-state heat transfer. The program is along with the three-dimensional version HEAT3 used by more than 1000 consultants and 100 universities and research institutes worldwide. The program is validated against the standard EN ISO 10211 and  EN ISO 10077-2. [click here for ISO 10211 & 10077-2 validation test cases]

Examples of applications [
click here for graphical examples]

· General heat conduction problems

· Thermal bridges

· Calculation of U-values for building construction parts

· Estimation of surface temperatures (condensation risks)

· Calculation of heat losses to the ground from a house

· Optimization of insulation fitting

· Analysis of floor heating systems

· Analysis of window frames


· Well tested and robust pc-program. Well documented with a succinct theory. Easy to learn to use. Handy and rapid input due to an integrated pre-processor.  Automatic mesh generation. Quick numerical method with optimization. Both steady-state and dynamic analysis. Multiple consecutive simulations may be started externally (batch mode).  

· HEAT2 handles calculations for temperature dependent material properties (thermal conductivity and heat capacity) and phase change (e.g. applications within fire safety design and soil freezing, etc.). It also handles a variable snow layer and cold spells more convenient.

· HEAT2 can import DWG, DXF, SVG, PLT, CGM, WMF, JPG, BMP, PNG, and some other formats. Note that Google Sketchup Pro can export dxf-files.

· PC-program now available in more than 40 languages: English, Arabic, Basque, Bosnian, Bulgarian, Catalan, Chinese Simple, Croatian, Czech, Danish, Dutch, Estonian, Farsi (Persian), Finnish, French, German, Greek, Hebrew, Hindi, Hungarian, Irish, Italian, Japanese, Korean, Latin, Latvian, Lithuanian, Norwegian, Polish, Portuguese, Romanian, Russian, Serbian Latin, Serbian Cyrillic, Slovene, Slovak, Spanish, Swedish, Turkish, Ukrainian, Vietnamese. New languages can be added.

· Post-processor with extensive graphical capabilities of geometry, materials, numerical mesh, boundary conditions, temperature field, heat flow arrays and isotherms. Features: zooming, panning, rotation, color/gray-scale, high resolution printing. Arbitrary heat flows and temperatures can be recorded (transient calculations).  Charts can be printed and exported in different formats (text, Excel, HTML, XML, Metafile, bitmap).

· Any structure consisting of adjacent or overlapping rectangles with any combination of materials may be simulated. Up to 6,250,000 (2,500·2,500) nodes may be used.

· Boundary conditions may be a given heat flow, or a temperature with a surface resistance. Temperatures and heat flows may vary in time (sinusoidal, stepwise constant, stepwise linear). Several formats with climatic data such as TRNSYS, DOE, METEONORM, HELIOS, TMY2, SUNCODE, MATCH, and EXCEL can be imported for dynamic calculations

· Available modifications: heat sources/sinks, internal boundaries of prescribed temperature, internal regions containing air or fluid of a single temperature, internal resistances, radiation inside cavities.

· The Report Generator produces on-the-fly a printable document with optional text and figures with project info, and input/output data.

· Automatic calculation of thermal coupling coefficient (L2D) and thermal transmittance (ψ) according to EN ISO 10211 for a wide variety of problems involving thermal bridges.

· Material properties may easily be edited and added. Several material list are available. The default list Default.mtl contains about 200 common building materials. The list General.mtl has over 1200 defined materials. Another file with over 200 materials (in German) from the German standard DIN (Deutsches Institut für Normung, DIN V 4108-4) is also available.

· Extensive window frame analysis has been implemented according to ISO 10077.



Click here for current version update info

Free light version: Click here to download a free light version  

 YouTube clips:

· Input example using rectangles, polygons, and bitmaps

· Input example using bitmaps. Also shows a bitmap of a window frame that is imported and filled with different materials.


Tips for reading for beginners: For a quick start read Chapter 4 (pages 23-27) in Manual HEAT2 5.0. The example in chapter 8 (pages 117-121) would also give a short introduction. After this, look at the update manuals for HEAT2 6.0, HEAT2 7.0, etc. Also see the EN ISO test cases: [ISO 10211 & 10077-2 validation test cases].


· Update manual HEAT2 10 (PDF) 


· Update manual HEAT2 9 (PDF) 


· What's new in version 8


· Update manual HEAT2 8 (PDF), 2011 


· Update manual HEAT2 7.0 (PDF), 2006 

Updatehandbuch HEAT2 7.0 (PDF), 2006

· Update manual HEAT2 6.0 (PDF), 2003


· Manual HEAT2 5.0 (PDF), 2000

· Frequently asked questions


· List of universities using HEAT2/HEAT3

· Theory of HEAT2/HEAT3, (Doctorate thesis, Blomberg), (PDF), 2.5 MB, 202 pages, 1996

A separate program that reads HEAT2 6+7 reports is available for free here: (600 kB)   (also contains an example of a generated report)






· United Kingdom: Training/certification is offered in English by Stroma.




· France: Training in French. Formation en français par

Psi Thermique 


· North America: Training is offered by




· CIS-countries, Latvia, Lithuania, and Estonia: see

· Denmark: See



Older versions
These versions were written for Windows 98/XP and we do not support them anymore.

Old version 7

· What's new in version 7


A separate program that reads HEAT2 6+7 reports is available for free here: (600 kB)   (also contains an example of a generated report)

Old version 6.0

· What's new in version 6 

Was ist neu in Version 6 (PDF, deutsch), 80 kB, 3 Seiten

· Update manual for HEAT2 6.0 (PDF), 600 kB, 25 pages, revised Sept 6, 2003

Updatehandbuch HEAT2 6.0 (PDF, deutsch), 600 kB, 25 Seiten, Stand 09.2003

Old version 5.0

· Info sheet (PDF), 120 kB  


· Manual for HEAT2 5.0 (PDF), 3.3 MB, 186 pages, revised Aug 1, 2000

Programmbeschreibung HEAT2 5.0 (PDF), deutsch, 3,8 MB, 179 Seiten

· Screen video of input for example 1 (see manual), 1.6 MB

· Bug report

Old version 4.0

· Manual (PDF), 2.6 MB, 149 pages, revised Nov 16, 1999

Version 3.0

· Manual (PDF), 1.8 MB, 125 pages, revised Oct 26, 1998