The IESNA Lighting Handbook provides illuminance design values for each occupancy classification. The difference is that the larger office needs more fixtures to reach 50 fc. Since illuminance is specified per unit of area, room size does not matter - an illuminance of 50 fc has the same meaning for 500 sq. Footcandle (fc) - lumens per square foot.There are two common measurement units for illuminance: The lighting needs a given occupancy are described with an illuminance value, which is unaffected by size. The concept of illuminance is used to describe the required lighting in built environments. For example, 10,000 lumens are more than enough light for a small office, but their effect is barely noticeable in a large warehouse. However, a different measurement unit is used to describe the lighting needed by a specific area. Lumens are useful when describing the output of lamps. From a financial standpoint, LED upgrades are among the best energy efficiency measures for buildings. Just like a car with a high MPG has a lower fuel cost per mile, a light source that produces many lumens per watt has a lower energy cost. ![]() If the three light bulbs described above produce 900 lumens each, their luminous efficacy values are the following: The concept of luminous efficacy describes how well a lamp converts watts into lumens, similar to the gas mileage (MPG) of a car. ![]() However, this comes from the old practice of describing brightness with watts, when the correct unit is the lumen.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |