# Demo Heat FAQ & More

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## FAQ

- What is the Bowen Ratio?
- The Bowen Ratio is the ratio between sensible and latent heating during heat transfer from a (moist) surface to its environment. This ratio is described by the following equation: Bowen ratio = sensible heat/ latent heat.
- See also: Bowen ratio (Heat Overlay)

- What is the Foliage Crown Factor?
- The Foliage Crown Factor is used for calculating the foliage extent of trees. This is more accurate than only using the extent of tree trunks. By applying the Foliage Crown Factor, these tree trunks are transposed into foliage crown extents, which are then used for Heat Stress calculations.
- See also: Foliage crown factor

- Which data do I need to provide and enter myself?
- Generally speaking, when using the Heat Stress Overlay Wizard, no extra data needs to be provided. The Heat stress Overlay Wizard uses the standard DPRA values and calculations for the Heat Stress model calculations. Some data sets can be improved upon by, for example, adding a more up to date set of trees or by actualizing other elements of the project area (buildings, terrain, etc). Since trees have a big impact on the result, our advice is to consider adding accurate tree data.
- See also: Data preparation

- Why does the Heat Stress calculation begin on a day in 2013, and not today?
- The Heat Stress calculation starts at 2 August 2013, because the DRPA benchmark case is also situated on 2 August 2013, in Wageningen.

- Which data is most important to set up?
- The Heat Stress Overlay Wizard asks for the required data when needed. Most important are the location of the project area and period over which the calculation needs to take place. Also important, for the Foliage crown factor, is the availability of an up to date tree data set, as the Tygron Platform uses public available data, which is not always complete. Besides the trees it is also important to know if the other spatial elements of the project area are up to date, such as terrains and buildings. Please note that for the Heat Stress calculation also the size of the grid cells needs to be taken into consideration, as this impacts the accuracy and length of the calculations.

- Why are the roofs black?
- Buildings and thus their roofs, contrary to their shadows, are not taken into consideration for the heat stress calculations in the DPRA model. This is a decision made in the DPRA Heat stress report due to the potential for inaccuracy and ambiguity for locations in and on construction.
- See also: https://www.rivm.nl/bibliotheek/rapporten/2019-0008.pdf

- Where can I ask questions about this Heat Stress module?
- On our forum you can find information on the latest updates, including this Heat Stress module, and ask questions if you didn't find the answer already as part of our HEAT module documentation.

- Where can I find more FAQ about the Tygron Platform?
- On our website you can find all FAQ's.

## Support

In case you need further assistance or extra information, we have the following support options available for all our users:

## Wiki pages

## Video Tutorials & Webinars

If you would like to learn how to create this demo project youself, please make use of the Heat Stress tutorial.

For more information on how to implement overlays please check this video tutorial.

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