# Calculating percentage of mesh area in LB Direct sun hours

Hi all and @chris

Is there any way to calculate the individual surface area of a grid in LB direct sun hours?
For example, the surface area which receives 2 hours of sun is 5 m2. Or the surface area which receives zero direct sun hour is 2 m2.

Thank you

Hi @ricardo,

You should be able to use the results and mesh outputs to get this. If you do == on the results and then the output of that to a cull mesh faces you should get the area of the mesh that gets exactly your target hours (that you input into ==).

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Hi @charlie.brooker
Thank you for the hint!
I have managed to produce that percentage using your method

However, I am trying to compare the result I get from LB Direct Sun Hours with HB Direct Sun Hours

Interestingly the result is different although I am using the same grid size, same EPW, and same analysis period. For example, the shaded part with no sun hours is 65% in LB Direct Sun Hours, while in HB Direct Sun Hours, only 47% is shaded. Still working to find out what happenedâ€¦

Hey @ricardo . I am pretty sure that I know the reason for this:

All â€śannualâ€ť radiance recipes in LBT Honeybee evaluate conditions on the half-hour mark (eg. 10:30). NOT the hour mark (eg. 10:00). The reason for this is probably more complex than this post merits but it results from the fact that the radiation values in the EPW file are essentially for the half-hour. Long story short, just make sure you are running your LB direct sun hours study using sun positions on the half-hour instead of the hour (eg. 10.5 instead of 10) and the direct results should match exactly between your Ladybug and Honeybee direct sun studies.

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