Daylight Zones (IECC 2009)
- Thread starter mvsawyer
- Start date
- Status
- Location
- Logan, Utah
Welcome to the forum.
The controls for the "Daylight zones" are not required to be automatic and can be nothing more than an additional switch that controls the lights with the daylight zone. There are lighting control systems that incorporate a daylight sensor and that will automatically shut off the lighting in the daylight zones as the sun moves.
Chris
The controls for the "Daylight zones" are not required to be automatic and can be nothing more than an additional switch that controls the lights with the daylight zone. There are lighting control systems that incorporate a daylight sensor and that will automatically shut off the lighting in the daylight zones as the sun moves.
Chris
Thanks for the reply and the welcome. Let's say I have an office that is 15'X15'X10' with an exterior window along one side. There are (3) 2x4 fluorescent lights in there. How would you handle daylight zone controls in this office? How do you set apart general lighting from daylight zone lighting?
Michael
Michael
I think daylight zone boundary is certain distance from window, check the code, couldn't remember.
Any lights in that zone need to be controlled independent from general lighting in room. This sounds ridiculous
but you may want to control the light in daylight zone by ceiling mounted occupancy sensor and room lighting
by another wall mounted occupancy sensor. Make sense?
maghazadeh
Senior Member
- Location
- Campbell CA
If you are in Califonia, you can find all informations in the Title-24.
Any area within 15 ft of natural lighting (windows, sky lights) consider to be day light zone and requirement is to reduce 50% of lighting in such area and as posted earlier with a wall switch or ceiling mounted photo cells. In your example 15' x 15' x 10', I assume 10' is your ceiling height then 15 x 15 = 225 sq. ft.
Another T-24 requirement is that if you have a office / room equal or larger than 100 sq. ft. then you shall have bi-level switching ( 2 sws & 2 sw leg) in order to reduce lighting level uniformely by 50% so this authomaicly comply with the first requirement since the room is only 15 ft wide.
There are some exception there that I can not recall.
Hope this helps.
Any area within 15 ft of natural lighting (windows, sky lights) consider to be day light zone and requirement is to reduce 50% of lighting in such area and as posted earlier with a wall switch or ceiling mounted photo cells. In your example 15' x 15' x 10', I assume 10' is your ceiling height then 15 x 15 = 225 sq. ft.
Another T-24 requirement is that if you have a office / room equal or larger than 100 sq. ft. then you shall have bi-level switching ( 2 sws & 2 sw leg) in order to reduce lighting level uniformely by 50% so this authomaicly comply with the first requirement since the room is only 15 ft wide.
There are some exception there that I can not recall.
Hope this helps.
maghazadeh
Senior Member
- Location
- Campbell CA
Your (3) 2x4 fixtures are either 2, 3, or 4 lamp fixtures, in any case, you need to have step dimming ballast or 2- ballats per fixture. (Step dimming ballast is a ballast with 2 input hot wires) then by using 2 wall switches or any combinations that will give you 2 seperate controls will satisfy day lighting requirement.
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