Dear srs, I'm doing a convention center in Arabia Saudi and we justify the LPD of the baseline model as this way:
1) We have chosen the Basic Power Allow ASHRAE (Table G3.7)
2) We have included the same power additional (9.6.2) and control factor (9.6.3) and RCR Factor in the rooms as the proposed model have.
For example
For the additional power (convention spaces and auditorium) the design team use a additional power 9.6.2. They increase the LPD in 7W/m2 for a design or esthetic purpose then I have increased the same 7W/m2 at the baseline model (adding to G3.7 LPD value)
If we do not increase in the baseline we have a lower LPD in the baseline than the proposed.
I had read some old post in this forum, that we can use the additional power ( 9.6.2, 9.6.3 and 9.6.4) in the two models without winning any energy saving, like it will be a process load.
The LEED reviewer say to us that it is not possible to use anyone of them, and we must use the Table G3.7. alone.
There is any "official" interpretation or clarification that we can justify to use this additional power in baseline?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5900 thumbs up
June 19, 2023 - 12:43 pm
The additional power allowances are only available in very limited and narrow situations. You will need to justify to the reviewer that one of those situations apply to your project in order to use the additional allowance. Sounds like they don't think so. You might want to look to the User's Manual. Even if you do apply the additional allowance it must be identical to the proposed in the baseline so as to not generate any savings. Not sure how this solves your fundamental problem if the baseline LPD is lower than the proposed?
Marc Maso
1 thumbs up
June 22, 2023 - 9:00 am
Dear Marcus, thank you very much for the reply. We had read some post in this forum where the additional power has been defined as process load. For example:
https://leeduser.buildinggreen.com/forum/additional-interior-lighting-power-1
We use this assumption in our project. Is the conception have been changed in v4.1?
I explain one room to clarify something... An exhibit space in the convention center
The for the energy model we use:
If the use of the additional power will be accepted, the way to justify the LPD are correct? Is better to introduce in the LPD 10,8 & 13,99 W/m2 and the 4,4W/m2 in both Miscellaneous box?
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5900 thumbs up
June 22, 2023 - 10:56 am
Yes it is essentially treated as a process load. But it can only be used if it meets the criteria associated with the additional allowance so make sure you provide justification for the reviewer. It appears as if you are applying the correct process in the model. I would provide the additional lighting energy use as a separate line item in the modeling results so that you can demonstrate that there is no energy savings associated with this additional power allowance.