LPD of Building Area Method

1. I would model 1 W/sf for office and 0.3 W/sf for Parking. Total LPD is for compliance with prescriptive power allowance not for modelling.

2. If you choose Building Area Method, you must use Building area method with the same Building criteria selection for proposed and Baseline and for proposed. So the answer is,Yes, model same LPD all parking, and same LPD in all office zones.

That said, in my experience Space by space always gives greater savings than Building Area Method. If you have the option go for that.

Best.

1. Modeling the two spaces with different LPDs is certainly more accurate. If you use 0.77 in all spaces you are shifting internal loads from conditioned to unconditioned spaces. Technically the reviewer is correct but sometimes the rules make no sense and should be slightly bent. This may or may not be a conservative approach. If it is conservative you could try to make that case.

2. You should use the same methodology in both the baseline and proposed models.

I agree that the savings is often greater using the space-by-space method. It is also the more accurate way to model most buildings.

Good to know the right way aligns with the guidelines!

Dear Marcus,

If we take a building area method, LPD will same value in all area.

However, I'm concered that each rooms internal lighting load.

It doesn't matter. It only matters if you are trying to "design" the baseline system. It is not designed in the same way as the proposed systems, so again it doesn't matter. Engineers seem to often fall into trying to design the baseline system but it doesn't have to actually operate in reality.

That said I think it is far more accurate to use the Space-by-Space Method so if you remain concerned, use that one.

Repeat