Clear Sky Solar Exposure is a metric that quantifies the amount of direct sunlight an area receives as a percentage over a specified time period, assuming ideal, cloudless sky conditions. Like other thermal comfort metrics, solar exposure is defined over a season and time of day such as morning, afternoon, or evening. The percentage is calculated by assessing the proportion of time during the given period that the area receives unobstructed sunlight. A 100% value means the area is exposed to direct sunlight for the entire time period, while a lower percentage reflects periods of shade from the built environment.
In addition to being a useful guide to understanding solar availability during different seasons in different spaces of a project, this metric is also used to understand the solar influence on thermal comfort analysis. Solar exposure would typically be run with the same season and time window slices as those used for thermal comfort. By comparing thermal comfort results in a period to the solar exposure and wind cooling potential for the same period, it is possible to gain insight into which factors are important and how best to up or down regulate those factors to improve comfort.
What is it measuring?
The color scale indicates the percentage of solar exposure an area experiences over the given season and time of day. 0% means a location does not see direct sun at any time during the specified period. 100% means the area is never shaded.
What options can I specify?
The Season and Time of Day.