I have a simulation problem i want to model. Imagine I have a thick tree canopy for say 50 m X 50 m patch of land. The trees cover and block direct light to ground. Neighbouring trees almost intersect each other. This can be casted into an approximate geometry in rhino.
I would like to know - the effect of tree cover on the region below the tree, in terms of the following params which can be called as the “micro-climate” below the tree cover –
a) Reduced air temperature due to shading of tree cover.
b) Reduced Soil Temperature as compared to areas that are outside the tree cover.
c) Effect of wind - as if wind comes in, the air temperature will be equalized as air that is outside the tree cover would mix with air that is inside.
An approximate conceptual study is also OK - to compare relative effects of different tree systems. Is there any way the “building” model of honeybee can be used for modelling this situation?
This sample file shows the “state of the art” for modeling the effect of trees on outdoor thermal comfort with honeybee:
It doesn’t do anything sophisticated with wind beyond using a standard profile curve and it doesn’t account for tree evapotranspiration (you should adjust the input EPW to account for these things). However, it accounts for all shading and radiant effects well, including the temperature of the ground surfaces. Note you can also use the E+ green roof vegetation material to account for vegetated surfaces beneath the trees:
Thanks for the reply. Will go through the same.
Just a followup question.
Since I am new to this tech - What is the boundary condition here, in an outdoor simulation?
In a building sim - i can understand we modelling all that is inside the bldg.
That hydra example there is admittedly using EnergyPlus in an unorthodox (albeit valid) way. Essentially, EnergyPlus is just being used to compute the outdoor surface temperature of the ground and that “Ground Zone” component that you see in the file makes all of the surfaces of a zone have a Ground boundary condition except the roof, which gets an outdoor boundary condition and a material construction that corresponds to the conductivity and heat capacity of soil or pavement. This way, the EnergyPlus solar distribution calculation computes the solar radiation falling on the “ground surface” (aka. the roof of the zone) and the E+ energy balance calculation is then run to give a time series surface temperature for that ground surface.