# 3.3.2 Interior Lighting

Inputs for interior lighting are specified at the space level (see specification below). In those instances when thermal blocks contain just one space, the inputs here will be identical to the inputs for the single space that is contained within the thermal block.

For those instances when a thermal block contains more than one space, the software shall either model the lighting separate for each space and sum energy consumption and heat gain for each time step of the analysis or it must incorporate some procedure to sum inputs or calculate weighted averages such that the lighting data used at the thermal block level is equal to the combination of lighting data for each of the spaces contained in the thermal block.

In some cases, combining lighting data at the space level into lighting data for the thermal block may be challenging and would have to be done at the level of each time step in the simulation. These cases include:

• A thermal block that contains some spaces that have daylighting and others that do not.
• A thermal block that contains spaces with different schedules of operation.
• A thermal block that contains some spaces that have a schedule adjusted in some way for lighting controls and other spaces that do not.
• Combinations of the above.