Table-top Heliodon

The Table-top heliodon can be used outdoors on a sunny day by using a sundial for adjusting the tilt and rotation of the model.

For use indoors, the table-top heliodon uses a clip-on lamp attached to the edge of a door with its position determined by the marked ribbon.

The table top heliodon consists of a model support device that can rotate and tilt a model, a clip-on lamp, and a ribbon mounted on a door.  The model support device is about 12 in. square (30 cm square) and rests on a conventional table or desk.

Table-top Heliodon

The greatest advantage of table-top heliodons is their very low cost and small size. They are accurate and valuable tools for solar-responsive design when used by people familiar with solar geometry and the basic principles of solar-responsive design. They can be used both indoors with electric lamps and outdoors with sunshine for even greater accuracy.

Table-top heliodons are not good for learning solar geometry or the basic principles of solar responsive design, because they are not intuitive or conceptually clear. They do not simulate our everyday experience of the sun moving across the sky dome.  Furthermore, the model of a building is never horizontal and is usually held at a very steep angle making viewing difficult, and the model must be well fastened to prevent it or its parts from sliding out of position.

Ribbon and clip-on lamp on door and model stand on a table

To simulate the time of year, the table-top heliodon uses a ribbon marked with the months of the year, which was designed to attach to the edge of a door. A clip-on light is then fastened to the door at a height corresponding to the month to be simulated. The model stand placed on a table, is tilted for latitude and rotated for time-of-day. When used outdoors with sunshine, or with a fixed light source indoors, a sundial for the appropriate latitude governs the tilt and rotation of the model stand.


Available at Cost

Because I want to encourage faculty, students, architects, and others to use a heliodon on their design projects, I had a local cabinet maker construct 10 heliodons for me with the intention of selling them at cost.  A table-top heliodon, a reflector lamp, a clip-on lamp holder, a ribbon marked with the months of the year, instructions, and sun dial charts are available at cost for $138.  The average postage for the continental US is $22.  Thus, the complete package costs $160 anywhere in the 48 contiguous states.  Elsewhere, it is $138 plus actual postage.


The table-top heliodon is of very high quality.  Its dimensions are 12” x 12” x 9” high when stored.  All the time that I am spending in assembling and shipping the heliodon packages is my contribution to a more sustainable planet.  If you would like a heliodon, send me a check for $160 and your address printed on a separate sheet of paper.  If you have any questions, don’t hesitate to contact me at:

Norbert Lechner

719 Mercer Circle

Auburn, AL 36830


The instructions for constructing the Table-top heliodon can be found in Appendix I of the book,  Heating Cooling Lighting: Sustainable Design Methods for Architects by Norbert M. Lechner, 4th edition ©2014, John Wiley & Sons.

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