Hi,
I am trying to model the lighting power for a core and shell office building, the lighting is designed for the core spaces such as main lobby, restrooms and BOH, but the tenant spaces are not. I am thinking of the below approaches to model the lighting power in the energy model:
Building Area Method: in the proposed building calculate the total designed lighting power and use 0.9 W/sf (from Table 9.5.1) for the tenant spaces, then added them together and divided by the total building area which resulted in 0.88 W/sf. For baseline building I used 0.9 W/sf
Space-By-Space method: in the proposed building I used the actual power for designed spaces and 0.9 W/sf for tenant spaces to meet the requirement of Table G3.1.6 (proposed)(c), "where lighting neither exists nor is specified, lighting power shall be determined in accordance with the Building Area Method for the appropriate building type”. For baseline building I used Table 9.6.1 to get the power for designed spaces and 0.9 W/sf for tenant spaces.
Are these approaches seem reasonable for each method?
Thank you,
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5912 thumbs up
April 10, 2019 - 11:35 am
You have to use the building area method and the LPD must be modeled identically in both models. If you want to claim any savings you must include requirements in the tenant lease agreement.
Saif Alsaeed
April 10, 2019 - 11:53 am
Thank you Marcus, for the tenant spaces we are not planning to claim any savings, but the lighting power is designed for the core spaces. Would my approach above for the BAM be appropriate to address these designed lighting power?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5912 thumbs up
April 10, 2019 - 12:36 pm
No. The values you used must be kept separate. The reviewer will not be able to determine that you modeled the tenant spaces identically otherwise.
Saif Alsaeed
April 10, 2019 - 12:54 pm
Understood, What if I calculated a W/sf for the designed spaces and modeled the tenant spaces identically at 0.9 W/sf? will that be a better approach?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5912 thumbs up
April 10, 2019 - 12:59 pm
The designed space in the proposed model must be modeled as designed. This is what needs to be separate. The baseline could all be the BAM value for an office.
Saif Alsaeed
April 10, 2019 - 1:14 pm
Thank you!