Transmittance schedule for trees

asked 2017-04-18 12:33:00 -0500

updated 2017-04-26 14:04:02 -0500

Has anyone got some references on transmittance schedules that could be used to model deciduous trees?

In E+ I mean to use Shading:Site:Detailed, in particular the field Transmittance Schedule Name, but this question is software-agnostic.

(Bonus point if you can find one in Europe)

edit retag flag offensive close merge delete


I found this study which is based on McPherson et al 1985 apparently. It assumes 75% Apr-Oct and 25% Jan-Mar / Nov-Dec.

Julien Marrec gravatar imageJulien Marrec ( 2017-04-18 12:41:02 -0500 )edit

That seems like reasonable starting point, there will always be uncertainty related to the type of tree, how it is maintained, and how old it is for the simulation year. Also the size one chooses to model it, it isn't always clear what the shading surface should look like, in some cases I modeled three intersecting octagons on x,y, and z. They were large trees close to the building so horizontal or vertical surface by itself didn't seem right.

David Goldwasser gravatar imageDavid Goldwasser ( 2017-04-18 13:14:01 -0500 )edit

There's an updated version in 1995 (published 1997) from McPherson, they use 0.7 summer and 0.175 winter.

Julien Marrec gravatar imageJulien Marrec ( 2017-04-19 08:59:38 -0500 )edit