Emergency Lighting - Electrician Talk - Professional Electrical Contractors Forum

dawgs · 06-02-2009, 10:54 AM

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.

sparkyboys · 06-02-2009, 02:32 PM

Quote:

Originally Posted by dawgs

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

480sparky · 06-02-2009, 02:34 PM

Quote:

Originally Posted by sparkyboys

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.

lectricboy · 06-02-2009, 03:30 PM

Quote:

Originally Posted by 480sparky

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.

This is what I was always taught.