# Emergency Lighting



## dawgs (Dec 1, 2007)

Is there a watts per square foot calculation for fiqureing emergency lighting loads? I am trying to size a life safety panel for future EM lighting.


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## sparkyboys (May 3, 2009)

dawgs said:


> Is there a watts per square foot calculation for fiqureing emergency lighting loads? I am trying to size a life safety panel for future EM lighting.


for what kind of building?
hospital- 2 volt-amps psqft
schools- 3
office buildings- 3 1/2


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## 480sparky (Sep 20, 2007)

sparkyboys said:


> for what kind of building?
> hospital- 2 volt-amps psqft
> schools- 3
> office buildings- 3 1/2


Those are general lighting loads used for calculations. They aren't for designing egress lighting.


_Life Safety Code_. Section 7.8.1.3 of NFPA 101 states, “The floors and other walking surfaces within an exit and within portions of the exit access and exit discharge designated in 7.8.1.1 shall be illuminated to values of _at least_ 1 footcandle measured at the floor.”
Section 7.9.2.1, “Performance of Systems,” dictates the following: “Emergency illumination shall be provided for a period of 1½ hours in the event of failure of normal lighting. Emergency lighting facilities shall be arranged to provide initial illumination that is at least an _average_ of 1 footcandle and a _minimum_ at any point of 0.1 footcandle measured along the path of egress at floor level. Illumination levels may decline to 0.6 footcandles average and a minimum at any point of 0.06 footcandles at the end of the emergency illumination lighting time duration. A maximum to minimum illumination uniformity ratio of 40-to-1 shall not be exceeded.”
_Uniform Building Code_. Section 1003.2.9.1 of the UBC states, “Any time a building is occupied, the means of egress shall be illuminated at an intensity of _not less_ than 1 footcandle at floor level.”
_International Building Code_. Section 1006.2, Illumination Level, of the IBC states, “The means of egress illumination level _shall not be less_ than 1 footcandle at the floor level.”
Section 1006.4, Performance of Systems, states: “Emergency lighting facilities shall be arranged to provide initial illumination that is _at least_ an average of 1 footcandle and a _minimum_ of any point of 0.1 footcandles measured along the path of egress at floor level.”

Source.


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## lectricboy (Mar 11, 2009)

480sparky said:


> Those are general lighting loads used for calculations. They aren't for designing egress lighting.
> 
> 
> _Life Safety Code_. Section 7.8.1.3 of NFPA 101 states, “The floors and other walking surfaces within an exit and within portions of the exit access and exit discharge designated in 7.8.1.1 shall be illuminated to values of _at least_ 1 footcandle measured at the floor.”
> ...


 This is what I was always taught.


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