For problems 1 and 2, six luminaires, similar to Style E used in the Commercial Building, are to be installed in a room that is 12 ft * 18 ft (∼3.7 m * ∼5.5 m) with a 9 ft (2.8 m) floor-to-ceiling height. The spacing ratio for the luminaire is 1:0. The maximum distance that the luminaires can be separated and achieve uniform illuminance is

7ft (2.13 m).

Explanation:

From the question above, the following parameters/data are given; the room dimension = 12 ft * 18 ft (∼3.7 m * ∼5.5 m), the floor-to-ceiling height = 9 ft (2.8 m) and the spacing ratio for the luminaire is 1:0.

Note that, we are not given the value or data for the height of the plane, therefore, we will make an assumption that the height of the plane = 2ft.

Hence, the work plane to luminaire distance = (9 - 2) ft = 7ft (2.13 m).

So, the maximum distance that the luminaires can be separated and achieve uniform illuminance is;

= the work plane to luminaire distance * spacing ratio for the luminaire.

= 7ft (2.13 m) * 1 = 7ft (2.13 m).

Thus, the maximum distance that the luminaires can be separated and achieve uniform illuminance is 7ft (2.13 m).