How to calculate the daylight factor

Written by bill brown
  • Share
  • Tweet
  • Share
  • Pin
  • Email
How to calculate the daylight factor
The daylight factor applies to interior light. (window image by aldaer from Fotolia.com)

The daylight factor is used to measure interior light. Specifically, it is a ratio of how much light strikes a given spot in an interior, as compared to how much light would strike an exterior spot at the same moment under identical conditions. The daylight factor is useful in figuring lighting requirements for interior use, especially if you seek to maximise natural light for economical or environmental reasons. There is a basic formula for calculating the daylight factor of a room without a light meter.

Skill level:
Moderate

Other People Are Reading

Things you need

  • Measuring tape
  • Calculator

Show MoreHide

Instructions

  1. 1

    Measure the length and width of your chosen room.

  2. 2

    Multiply the dimensions together. This yields the area of the room. For instance, if the room is 17 feet by 19 feet, the area is 323 square feet.

  3. 3

    Measure the area of the windows. For example if you have three windows in the room that each are 3 feet by 5 feet, the total is 45 square feet.

  4. 4

    Divide the window area by the room area. Here, 45 divided by 323 is 0.139.

  5. 5

    Express your result in Step 4 as a percentage. In this calculation, 0.139 expressed as a percentage is 13.9 per cent.

  6. 6

    Multiply the percentage figure by 0.1 to get the daylight factor. Here, 13.9 times 0.1 is 1.39.

Don't Miss

Filter:
  • All types
  • Articles
  • Slideshows
  • Videos
Sort:
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the eHow.co.uk site, you consent to the use of cookies. For more information, please see our Cookie policy.