We are pursueing OPTION 1 (Whole Building Simulation). Thus we also have to comply to the mandatory provisions, e.g. section 9.4 for lighting.
Section 9.4 does not mention the interior lighting power density and the calculation according the building-area-method or space-by-space (from section 9.5 or 9.6). These are part of the prescriptive requirements under 9.2.2.
However, the interactional compliance form linked in the LEED-Online template includes a table which comprises the interior lighting power density...
Hence my question is wether we have to meet the interior lighting power density according building-area-method (or space-by-space) if we are pursuing OPTION 1?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
May 15, 2012 - 8:58 am
You have the option of using either method in your models, however, you must use the same method in both.
Marco Abdallah
32 thumbs up
May 15, 2012 - 9:59 am
Thank you for you fast response, the question was if we generally have to consider the lighting power density in EAp2. According to the RG p237 we just have to consider the mandatory provisions (sec. 9.4) which do not mention the lighting power density.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
May 15, 2012 - 1:30 pm
Lighting power density is not a mandatory provision so it is tradeable and does not have to be addressed for the prerequisite.
Marco Abdallah
32 thumbs up
May 16, 2012 - 4:46 am
So I understand you that we don't have to consider the interior lighting allowance from ASHRAE 9.5 or 9.6 because the interior lighting density is already included in the simulation.
On the other hand the RefGuide on p245, 'Section 9. Lighting Requirements' below 'Implementation' says: "These requirements apply to all lighting installed on the building site, including interior and exterior lighting. ... Interior lighting comliance must be documeted using eiter the building area method (9.5) or the space-by-space method (9.6)"
This seems to be contradicting, is there any explanation?
Thanks in advance!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
May 16, 2012 - 9:14 am
This portion of the Reference Guide is just a summary of 90.1. The lighting power density for interior lighting can be greater than the allowances from 9.5 or 9.6, as long as you make up the negative savings elsewhere and make it to the minimum. Exterior lighting must comply since it is in section 9.4 and is therefore a mandatory provision.