Calibrating the sky illuminance

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Permalink Reply by Chris Mackey on November 20, 2015 at 10:17am

Masoumehta,

If you have both "Direct Normal Illuminance" and "Diffuse Horizontal Illuminance" measurements, you can create a high-accuracy calibrated sky by using the "Honeybee_Generate Custom Sky" component.

If you only have a Global Horizontal Illuminance value, you can create a uniform sky by using the "Honeybee_Generate Sky With Certain Illuminance level" component.  However, this is going to be very inaccurate unless the values that you have recorded are for an overcast cloudy day.

-Chris

Permalink Reply by masoumehta on November 20, 2015 at 1:26pm

thank you very much chris, I'll try this.

-masoumeh

Permalink Reply by Mostapha Sadeghipour Roudsari on November 20, 2015 at 5:02pm

Chris said it all. Just a warning that if you're creating the sky for a non-cloudy day then using the second method is not recommended. You can use watch the sky component to check the illuminance value under the generated sky. A good place to start is probably the weather data around the time that you have done the measurement:

If you have an HDR image of the sky there are more advanced solutions that you can find on the web.

Attachments:

• customWeatherFile.gh, 433 KB

Permalink Reply by masoumehta on November 21, 2015 at 2:09pm

thanks alot mostafa!