Different protractor types are available for different window types. This will be influenced primarily by the areas and geometry of openings together with other factors such as ground reflectance, internal room reflectance, influence of shading devices, etc.
“The daylight factor is the ratio of the internal illuminance to the external illuminance, available simultaneously” (Muneer, 2004). The protractors calculate the sky component of daylight factor. The higher the DF, the more natural light is available in the room. daylight factor. To interactively improve your design at the schematic design stage.

If DF has to be calculated (perhaps for academic reasons), then the graphical method using the BRE Protractor for Uniform Sky (also overcast like CIE sky, but with uniform luminance) is the next best thing and is recommended to avoid oversizing windows as heat gain and glare is an issue here, all year round. The daylight factor (DF) is a very common and easy to use measure for the subjective daylight quality in a room. Competitive edge: high demand for simulationists Opportunity to work on more interesting projects. Faster computers. In conjunction with BRE Digests 309 and 310, they can be used to find the daylight factor at a point indoors.

The calculation of the sky component (daylight factor) is as follows:

It is expressed as such: It describes the ratio of outside illuminance over inside illuminance, expressed in per cent. As already explained the day lighting performance of a building is normally specified by the daylight factor. If you use the popover buttons in the bottom-left of the window, you can overlay the frequency distribution of daylight factors over the whole room or even a visualisation of the daylight factor protractor calculations for the currently selected window. The higher the DF, the more natural light is available in the room. 3. • DF = 100 * Ein / Eext – Ein - inside illuminance at a fixed point Better interfaces. For the full set, see package AP68. Title: Daylight protractor No 2 Subtitle: Ref Code: AP69 Authors: Abstract1: Protractor for an overcast sky and vertical glazing only. The calculation of daylight factor in this studio has been scrutinized by daylight protractors, Ecotect A design studio is selected as the case study for this thesis. To be able to engage in a dialogue with the HVAC engineer.
• It describes the ratio of outside illuminance over inside illuminance, expressed in per cent.

These are used in conjunction with scale drawings of the room being assessed to determine the daylight factor of a room. Architects! BRE Daylight Factor Protractor A daylight protractor contains two semi-circular scales on transparent overlays (see McMullan). Some of the overlays also include dynamic sliders that let you change room properties and see their effects update dynamically. Daylight Factor Calculation Method. • The daylight factor (DF) is a very common and easy to use measure for the subjective daylight quality in a room. Visualization Daylight Factor Distribution Who should ‘do’ daylight simulations? daylight factor prediction.