Lumen definition professional#

Other parasitic power losses (such as inefficiencies of the control gear/ballast) of the light fixtureĪ light engineering term exists for the measurement of the rate at which a lamp is able to convert electrical power (Watts) to Light (Lumens) – this is referred to as luminous efficacy (or just efficacy) – and is expressed in Lumens per watt (LPW) or Lumens per circuit Watt.Heat output generated (including the infra-red part of the lighting spectrum).Energy required in creating 'visible' light emitted from the lamp.The rated wattage of a light source refers to the entire power consumed in creating the light Lumens and includes the: The power required to operate an installed light fitting (or luminaire) is measured as a rated Wattage (Watts being Joules of energy per second). Bigger commercial & industrial buildings (such as factories and warehouses) have large open spaces so a large number of high power light fittings ('high bay' and 'low bay' types)are generally required.Įfficacy: the relationship between Lumens & Watts Lighting larger areas to the same necessary lux levels will requires a larger measured level of lumens – this is usually achieved by increasing the number of light fixtures (and hence the power consumed). The same 1,000 Lumens, spread out over ten square metres, produces an illuminance level of only 100 Lux. So 1,000 lumens, concentrated into an area of one square metre, lights up that square metre with an illuminance level of 1000 lux. To put it another way:Ī specification in lux tells you how many Lumens (total light output) you need given the measured area you are trying to illuminate. One lux (1 lux) is defined as being equivalent to one lumen spread over an area of one square metre. * Please note that these are sample figures for example purposes only & the actual output can vary. Office ceiling lighting panel installations

General domestic & task lighting applications High bay factory lighting or warehouse lighting lighting installationsĮnergy efficient replacement for 400W metal halide and sodium high bays Some examples of total lumens output (as measured in lumens) from common commercial & industrial light sources are given below: This total measured light may also be referred to by commercial or industrial lighting engineers as 'luminous flux'. The lumen is a standardised unit of measurement of the total 'amount' of light packets (or quanta if you want to get technical!) that is produced by the light source - such as a lamp, tube or LED chip. its lumens output) and the desired surface area to be lit. The lighting output of a light fitting is typically reported as a lumens output - the intensity of light on a surface (the lux) is dependent on the intensity of the light source (i.e.

Lumen definition professional#

professional indoor sport, detailed drawing or mechanical work, prolonged small size & low contrast visual work etc., this can require illumination levels from 1,500 all the way up to 20,000 lux in extreme cases. School Classroom, University Lecture Hallįor commercial & industrial environments where specialised tasks are performed e.g. Office, Show Rooms, Laboratories, Kitchens