APSH

The Annual Probable Sunlight Hours (APSH) is an indicator of the quantity of sun that a window will receive in a given environment. It is intended to be a simple measurement for the early stages of design. It is often used in conjunction with VSC indicator for skylight.

It compares the number of hours of sun that a window will receive to the number of hours of sunny sky. That indicator gives a quick idea of how the project handles sunny times.

This indicator depends on geometry, the environment, the climatic data. Therefore, as soon as the geometry is defined it can be calculated.

In the UK, the BRE gives recommendations will values of this indicator.

In DL-Light, APSH (or Wpsh for winter period) can be easily calculated and images and reports are produced for quick understanding.