The conflict between high bay lights and ESFR sprinkler system

[dahualin]

High bay fluorescent lights are getting popular in big box building such as warehouses and big retail buildings. Most of big box buildings have ESFR sprinkler system. High bay lights have to be installed as high as possible to avoid blocking water spray from sprinkler heads because of its bigger size than HID fixture. Normally the bottom of light fixture is higher than the bottom of joists. I have received a lot of lighting fixture catalogs with pictures showing the high bay lights installed much lower than structural joist. Do they block the sprinkler water spray? Is that a code (sprinkler code) violation?

Anybody has this kind of experience or conflict? Thanks.

 

[cleveland]

NFPA 13, Standard for the Installation of Sprinkler Systems has several requirements for dealing with "position of sprinklers to avoid obstructions to
discharge." I recommend getting this code. You are very correct in there being concerns. The Standard has required distances that must be kept in order to not conflict with the proper operation of the sprinkler head. My personal experience involved putting in new lights on a wood ceiling that had heads. These lights were very shallow but still ended up as a conflict. We solved the matter by getting a very short extension put on the head to lower it a bit. Then when we did more of the same we added a nice big note telling the electricans to maintain a minmimum horizontal distance of 18" from any sprinkler head which met our particular condition.