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

Examples of applications

· 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).
  • Post-processor with extensive graphical capabilities in 2D and 3D 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). The Movie Maker captures graphical output data, such as temperatures, isotherms, and heat flows to an AVI-file.
  • Any structure consisting of adjacent or overlapping rectangles with any combination of materials may be simulated. Up to 50 million nodes may be used (requires a PC with 3 GB RAM).
  • Boundary conditions may be a given heat flow, or a temperature with a surface resistance. Temperatures 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.
  • 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 coefficients(L3D) 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 listDefault.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.


Graphical examples

A few examples of applications

Surface temperatures for a corner with wall/floor connection.

HEAT3: Integrated circuit with solder balls, 30 million nodes.

Steel beam through corner: materials (top left), boundary conditions (top right), temperatures in steel partly exposed (bottom left),  heat flows in steel partly exposed (bottom right).

Temperaturefield along a steel bean inside a wall/roof-connection (all other wall materials are made invisable here)

HEAT3 user interface.

HEAT3 on the cover of issue 6, 2001, of Bauphysik.

HEAT3 on the cover of issue 6, 2001, of Bauphysik.

Version update info

Version update info for HEAT3

Current version of HEAT3 is 8.02

Use the update function (menu item Info/Check for updates) to see if there are any updates. This will show the download link to the setup program. Note that you can also use the (same) download link you got in the order email since it always will contain the most recent version.

Version 8.02
May 9, 2017

  • Clicking on object-inspector for a heat source showed a too small window that needed to be resized in order to show data.

Version 8.01b
April 27, 2017

Version 8.01
March 23, 2017

  • The complete geometry can now efficiently be described by text. It is also possible to vice versa convert already drawn geometry in the pre-processor to a script.

Old versions:

Version 7.11 update
August 30, 2016

  • Compatibility with Windows 10 Anniversary added.

Version 7.1 update
March 9, 2016

  • Bug fix for material editor that “froze” on certain systems.
  • Some minor fine tuning.

Version 7.0
June 15, 2015:

  • Parallel computation.HEAT3 now solves larger problems much faster using multiple cores (CPU:s) for both steady-state and transient cases. For large problems there may be up to 4-5 times of speed increase. E.g. a problem that took 1h to solve with version 6 (single core) may take about 15 min to be solved using version 7 (multi core) on a PC with 4 cores.

Version 6.1 update
April 8, 2015:

  • Better adaption to Windows Vista, Windows 7 and Windows 8
  • Several instances of HEAT3 can now be started and active at the same time. This will allow you to work (input and solve) multiple cases at the same time. Solving e.g. 3-4 cases parallel on a CPU with four cores, or 5-6 cases on a CPU with 6 cores should be very efficient.
  • The number of colors (materials) and legends shown in the post-processor was limited to 15 in old versions. This is now increased to 30.
  • New improved license management system.Your “old” license key for HEAT3 v6.0-v6.03 needs to be converted to a new product key for v6.1.    This can be made here: Generate new product key.

To upgrade your old license of HEAT3 v6.0-v6.03 to v6.1 please use the update function in HEAT3 (menu item ”Info/Check for updates”).

Version 6.03 update
March 22, 2012:

  • Save path for input files (*.h3p), temperature files (*.ijk), and recorder files (*.rec) was not saved to the recent folder. This is now fixed.
  • The heat transfer resistance for a boundary condition with a temperature function was not saved in the h3p-file. This is now fixed.

Version 6.02 update
Aug 1, 2011:

  • Improved input on the length panel at the bottom of the pre-processor.

Version 6.01 update
June 28, 2011:

  • Datafiles (*.h3p) where always saved to location “…DocumentsBloconHEAT3 6”, even
    though another folder (e.g. the Projects folder) where chosen. This is now fixed.

Old versions:

Update for version 5.0 to version 5.1

Note: This update will only work if you already have a working license of HEAT3 5.0.

If you have a school license or company site license and have not received this update please contact us. The version below will not work for school and site licenses.

  1. Download this zip file:HEAT3_51.zip.
    2. Extract ”HEAT3_51.exe” and place it in the same folder as ”HEAT3_Full.exe” .Version 5.1 update

  • Fixed error message ”HEAT3 is registered but ActiveX does not exists”. This alert came in some cases for a user without admin rights running HEAT3 under Vista and XP.
  • Max number of BC boxes increased from 12 to 30
  • Recorder: fixed label “Q, point (x,Y) [W/m?]” => “Q, point (x,Y) [W/m2]”.
  • System info: “Available virtual memory” was negative if RAM size was above 2 GB.
  • Options for steady-state: option for optimization of over-relaxation is now saved to file.
  • Function steps editor: “Paste from clipboard” added to menu.

List of 100+ universities and research institutes in 25 countries that uses HEAT2/HEAT3

Ciudad Universitaria, Buenos Aires


Dept. Building Physics, Univ. of  Technology Vienna, Vienna Technische Universität Graz, Inst. für Hoch- und Industriebau, Graz Spektrum – Zentrum für Umwelttechnik und Management, Goetzis Energie Tirol, Lienz Bautechnisches Institut GmbH, Linz ETH Zürich, Building Tech., Building Physics, Zürich


SCK-CEN, Waste and Disposal, Mol

University of Waterloo, Waterloo National Research Council, Ottawa

Department of Civil Engineering (BYG.DTU), Technical University of Denmark
Statens Byggeforskningsinstitut, SBI DTI Byggeri/Komponentcentret, Århus DTI Byggeri, Taastrup Teknologisk Institut, Taastrup

National Physical Laboratory (NPL), Middlesex
Staffordshire University, School of Computing, Staffordshire
Oxford Brookes University, School of Architecture, Headington

Oulu Polytechnic/Technical Institute
VTT Building Technology, Oulo Helsinki University of Technology (HUT), Helsinki
VTT Building and Transport, Espoo
University of Applied Sciences of Vaasa

Centre Scientifique et Technique du Bâtiment (CSTB), Grenoble
Centre Scientifique et Technique du Bâtiment, Saint-Martin-d’Hères
Institut National des Sciences Appliquées de Lyon (INSA), Villeurbanne
Universite de Savoie, ESIGEC, Le Bourget du Lac

Fraunhofer Institut Bauphysik, Stuttgart
Institut für Solarenergieforschung (ISFH), Emmerthal
Technische Universität Darmstadt, Inst. für MassivBau
Bayerisches Zentrum für Angewandte Energieforschung (ZAE) Bayern, Division Thermal Insulation and Heat Transfer, Würzburg
Passivhaus Institut, Darmstadt
Richard Grün Institut, Ratingen
Bauhaus-Universität Weimar, Weimar
Zentrum für Sonnenenergie- und Wasserstoff-Forschung (ZSW), Stuttgart
Institut für Gebäudeanalyse und Sanierungsplanung, Schliersee
Bauernhausmuseum, Amerang
Fachbereich Physik, Siegen
IZF, Essen
Universität Hannover, Institut für Bautechnik und Entwerfen, Hannover
ZAE-Bayern, München
Fachhochschule Stuttgart, Hochschule für Technik, Stuttgart
Institute for X-Ray Physics (IRP), University Georgia Augusta, Goettingen
Universität Kaiserslautern, Fachgebiet Bauphysik
Universität Leipzig, Institut für Massivbau
Bavarian Centre of Applied Energy Research, Würzburg
Forschungsinst. für Wärmeschutz, Gräfelfin
Hochschule für Bauwesen und Wirtschaft, FH Biberach
Baukonstruktionen und Bauphysik, Universität Rostock, Wismar
Institut für Trocken- und Leichtbau (ITL), TU Darmstadt
University of Applied Sciences, Darmstadt
Institut für Straßenwesen und Eisenbahn, Ruhr-Universität Bochum
Baugrundinstitut, Leutkirch-Herbrazhof
Landeshauptstadt Stuttgart, Stuttgart
Hochschule für Technik, Wirtschaft und Kultur, Leipzig
SLG Prüf- und Zertifizierungs GmbH, Hartmannsdorf
Institut für Bauphysik, Baustoffe und Konstruktion, Bochum
Fachhochschule Bochum, Angewandte Umwelttechnik, Bochum


Budapest Univ. Faculty of Arch. Eng., Budapest


University of Rome, Faculty of Architecture, Rome
Istituto di Edilizia, Ancona
Istituto di Fisica Technica, Padova,
University of Venice, Faculty of Architecture, Venice


University of Tokyo, Faculty of Engineering, Tokyo
Morioka Junior College, Iwate Prefectural Univ, Takizawa
TongMyong University of Information Technology, Busan

Construction Materials Research Team (RIST), Hwasung, Kyungkido
Dept. of Architecture SungKyunKwan University, Suwon-city
Architectural Engineering, Daejeon University, Youngun-dong, Dong-gu

Kuwait Institute for Scientific Research, Safat

Norges Byggforskningsinstitutt, Oslo
Norges Byggforskningsinstitutt, Trondheim
The Foundation of Scientific and Industrial Research at the Norwegian Institute of Technology, NTH, (SINTEF), Trondheim
Agder University College, Grimstad
Dept. of Building and Construction Eng., Norwegian University of Science and Tech, Trondheim

New Zealand
Building Research Association (BRANZ), Porirua

Building Research Institute, Warsaw

Universidade Nova de Lisboa, Quinta da Torre
Laboratório Nacional de Engenharia Civil, (LNEC), Lisboa

Instituto de Ingeniería Energética, Universidad Politécnica de Valencia
Universitat Politècnica de Catalunya, Sant Cugat del Valle


Institut für Hochbautechnik, Zürich
Ecole d’ingénieurs de Genève, EIG, Geneve
C.U.E.P.E, Université de Geneve
Laboratory of Energy, Ecology and Economy of the Scuola Universitaria, Professionale della Svizzera (LEEE-SUPSI)
Estia SA, PSE-EPFL, Lausanne

Uppsala Universitet, Ingenjörsutbildningen, Uppsala
Tillämpad fysik och elektronik, Umeå Universitet
Lund University (LTH), Lund
Chalmers University of Technology, Göteborg
Malmö Högskola
Royal Institute of Technology (KTH), Haninge
Swedish National Testing and Research Institute (SP), Borås
Building Technology, University College of Borås

Tübitak, ITU, Mimarlik Fakultesi, Ankara

Building Technology Program, M.I.T., Cambridge
Department of Chemistry, Drexel University, Philadelphia
Fraunhofer Resource Center, Michigan
Lawrence Berkeley National Laboratory, Building Tech. Dept., Berkeley
National Water Quality Assessment, U.S. Geological Survey, Urbana
Oak Ridge National Laboratory, ORNL, Oak Ridge
Dept. of Civil and Architectural Engineering, Illinois Institute of Technology

Download free demo version

Download light version of HEAT3 8

Please fill in the following form. A password is required to install the program. The download link and password will be sent immediately to your email

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