Good afternoon all,

We are in the process of modeling an hotel type building, and we are reviewing if we can claim savings due to reductions in lighting power in the guest rooms or if we need to treat these spaces as neutral for lighting power purposes (as in a dwelling unit).

As we understand it, the spaces that are out of the scope of section 9, are dwelling units, which a hotel guestroom should not fall into since it is not a permanent residence, and therefore all section 9.4 mandatories regarding lighting apply; however when reviewing how to model the proposed and baseline LPDs for these spaces, there is table G3.1.6.d which basically says that all lighting needs to be counted, but it has an exception:

         Exception: For multifamily dwelling units, hotel/motel guest rooms, and other

         spaces in which lighting systems are connected via receptacles and are not
         shown or provided for on building plans, assume identical lighting power for
         the proposed and baseline building designs in the simulations

And that land us in a situation where we can have a few different scenarios:

  1. If we have a guest room with both lighting fixtures and lamps, with known power, should we use the total lighting power for the proposed LPD (adding hardwire and receptacle lighting) and the baseline would be 1.11 W/SF per table 9.6.1? This means the baseline model would include the receptacle lighting in the 1.1 W/SF.
  2. If we have the guestroom with only the lighting fixture known (the hardwired lighting), but the lamp's power is unknown. Should we assume a lighting power for the lamps, consider this lamp power a process load, and therefore model the same in proposed and baseline, but for the LPD of the room use only the proposed lighting fixture power and compared that to the 1.11 W/SF? Or should we model both baseline and proposed in a neutral way with the same LPD, and model (or not) the lighting via receptacle as a process load in both models?

Thank you,