ASHRAE 90.1-2004

Section: 9.6.2/9.6.3 - Additional Interior Lighting Power

Toolbox

9.6.2

When using the space-by-space method, an increase in the interior lighting power allowance is allowed for specific lighting functions. Additional power shall be allowed only if the specified lighting is installed, shall be used only for the specified luminaires, and shall not be used for any other purpose or in any other space.

9.6.3

An increase in the interior lighting power allowance is permitted in the following cases:

1. For spaces in which lighting is specified to be installed in addition to the general lighting for the purpose of decorative appearance, such as chandelier-type luminaries or sconces or for highlighting art or exhibits, provided that the additional lighting power shall not exceed 1.0 W/ft² of such spaces.
2. For spaces in which lighting is specified to be installed to meet the requirements of visual display terminals as the primary viewing task, provided that the additional lighting power shall not exceed 0.35 W/ft² of such spaces and that the specified luminaire meets requirements for use in such spaces. Maximum average luminance measured from the vertical in candelas per square foot of not more than

   80 cd/ft² at 65 degrees,

   33 cd/ft² at 75 degrees, and

   17 cd/ft2 at 85 to 90 degrees.

3. For lighting equipment installed in retail spaces that is specifically designed and directed to highlight merchandise, provided that the additional lighting power shall not exceed

   (1) 1.6 W/ft² times the area of specific display or

   (2) 3.9 W/ft² times the area of specific display for valuable merchandise, such as jewelry, fine apparel and accessories, china and silver, art, and similar items, where detailed display and examination of merchandise are important.
    

Exceptions:

None.