Local time or GMT in uccupancy.

aleix · Posts: 1

In site/location you set dayligtht saving and local time(ie GMT+1) and in Activity you edit the occupancy time (ie 8:00 to 17:00) at local time. But when visualizing, generating shadows, cooling design and simulating, the solar altitude and azimut does not correspond to local time. Should we introduce GMT time in occupancy? If yes how will calculations take in account daylight savings?.

Andy Tindale · Posts: 1205 Location: Stroud

Aleix,

DesignBuilder allows you to model the effect of daylight saving time where the clocks are moved forward one hour in the summer months in non-equatorial countries. This is handled automatically when you load data from one of the location templates supplied with the program, but there are nevertheless some factors you should be aware of:

1. Simulation results are displayed in 'local mean time'. This means that during the summer, occupancy will be recorded as starting one hour earlier than local time. To help you pinpoint this, DesignBuilder prints the times when daylight saving starts and ends. This does not affect the accuracy of your output but you need to be aware of it so that you can add one hour if you want to report data in local time.

2. Visualisations use local mean time when setting the position of the sun for site shading analysis. Again you should add one hour to supply time in local summertime format.

Regards

Andy

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