Definitions by Fire Safety

Universal hallway constant 

Generally denoted by K, the universal constant is used in calculating the proper density and distribution of smoke detectors in a house hallway. While the constant can not be mathematically derived, it's value has been estimated at 150, and has units of square feet/kitchen*staircase.

Dude, to be able to tell you how many smoke detectors you'll need, I need to know the proper universal hallway constant.

Universal hallway constant by Fire Safety October 21, 2010