Internal Source

Internal Source tab on Constructions Dialog.


The internal source tab is visible only when the model is set to use Detailed HVAC. It allows data on the position and nature of any heating or cooling pipes included within the construction. The internal source is associated with either Heated floors or Chilled ceiling components by virtue of the construction being selected as the floor/ceiling in a zone with heated floor or chilled ceiling defined. For example in the case of a heated floor the heated floor component must be added to the appropriate HVAC zones, but also a floor construction with an internal source must be associated with the floor surfaces in that building zone. If you set up a model with a heated floor added to an HVAC zone whose equivalent building zone has any floor surfaces with a floor construction selected not having an internal source then an error will be generated.

Internal source

Check this option if the construction includes a heating or cooling source.

Layer after which the internal source is positioned

Enter a number between 1 and 1-the number of layers. Entering 1 means that the source is positioned between the outermost layer and the next layer. If you are defining a heated floor construction then you will normally enter 1-the number of layers. The easiest way to do this is to use the Set source position below innermost layer tool described below. When defining a chilled ceiling as a floor construction you should enter a value of 1 here.


This field refers to the detail level of the calculation. Select from the 2 options below for a 1-D or 2-D solution:


Tube spacing

This field defines how far apart (in m or in) the hydronic tubing are spaced in the direction perpendicular to the main direction of heat transfer. This parameter is only used when the 2-D solution is selected (above).

Set source position below innermost layer

A tool is provided in the info panel when using learning mode which calculates which is the innermost layer and adds the source between this and the next layer. For example in a chilled ceiling construction you might have 0.5 mm steel ceiling panel as the innermost layer with 3 other layers. In this case when clicking on the Set source position below innermost layer link, the innermost layer value would be set to 3.