Hi all,
I'm currently working in a project of shopping mall (common areas + tenant areas) pursuing LEED certification (Core&Shell). In tenant areas, a relevant part of the total installed lighting power is dedicated to highlight merchandise. Due to this, and according to ASHRAE 90.1-2010 section 9.6.2b), there is an additional power allowance that can be considered, depending on which type of merchandise is sold in each area. Thus, I have two questions:
1) for simulation purposes, the baseline building shall consider this additional lighting power in tenant areas, correct?
2) due to the type of project (shopping mall), at this phase it is not possible to predict accurately the type of merchandise that will be sold in each tenant area. Thus, can we consider an typical mix of tenant areas (based on simillar projects of the same company) in order to calculate the additional lighting power (e.g.: 40% of tenant areas refer to clothing, 20% refers to jewelry, 20% refers to sporting goods and small electronics and the remaing area refers to restaurants).
Thanks in advance,
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
November 22, 2016 - 12:19 pm
1. The additional allowance gets modeled in the baseline identical to the proposed. You cannot claim any savings associated with this extra allowance.
2. The approach seems reasonable. As long as you present a reasonable methodology it should be accepted.
Ricardo Sá
Director of SustainabilityEdifícios Saudáveis Consultores (503 910 767)
85 thumbs up
November 23, 2016 - 6:31 am
Regarding the additional interior lighting power calculation for a tenant space in a shopping mall, is it possible to consider the following allowances?
1) 10,8 W/m2 since the general lighting is installed not only for lighting purposes but also for decorative appearance (please see ASHRAE 90.1-2010 section 9.6.2 a);
2) the additional lighting power associated with the type of merchandise (e.g. clothing, cosmetics, jewelry, etc - please see ASHRAE 90.1-2010 section 9.6.2b).
Additionally, can you you confirm that the reference area to be used for additional lighting power calculation (please see ASHRAE 90.1-2010 section 9.6.2b) is the total tenant area? Or there are some areas such as the circulations between the shelves that are not included?
Regards,
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
November 23, 2016 - 9:29 am
1, You can only claim an additional allowance if the lighting in question is installed and controlled separate from the general lighting. If the general lighting also provides the decorative function you cannot claim an additional allowance.
2. You can claim the additional allowance for separate lighting systems that highlight merchandise.
No it is not the total tenant area. It is only the area of the merchandise on display.
Ricardo Sá
Director of SustainabilityEdifícios Saudáveis Consultores (503 910 767)
85 thumbs up
November 23, 2016 - 10:22 am
Regarding your answer can you please confirm:
1) In the tenant areas is it possible to consider allowance 1 (10,8 W/m2, applied to all tenant area) + allowance 2 (XX W/m2, depending on the type of shop, applied to merchandise area only);
2) If the tenant layout is not yet defined, is there any default ratio (area of merchandise / total area) that can be considered to determine the additional lighting allowance?
Many thanks!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
November 23, 2016 - 10:45 am
1. Yes you add the general lighting allowance and the additional allowance. However you can only claim the additional allowance up the to amount in the proposed lighting design. If there is no lighting design I suppose you could just make an estimate but it must be identical in the Baseline model as well.
2. There is no default I know of. What you appear to be trying to do in a CS project is going to be difficult to determine with any degree of accuracy. I think it is OK to try but there is no advantage to doing so since you cannot claim any savings.
Martina Dell'antonio
Distretto Tecnologico Trentino scarlJanuary 19, 2024 - 10:50 am
Hi Marcus, I have a similar question concerning the modelling of lighting and process loads for a LEED v4 ID+C: Retail.
The main activity of the building is retail, only one room is used for this purpose, while the other rooms are used for auxiliary functions (storage, restrooms etc..).
In the shop area the design lighting power is higher than the baseline, at first sight I understand that it is possible to increase the baseline lighting power up to the design lighting power, within the limits of the Additional Lighting Power according to to section 9.6.2 of ASHRAE 90.1 2010, in order to level the baseline lighting power to the design one.
However, it is also said that "The additional allowance gets modeled in the baseline identical to the proposed", which is also what happens in the Minimum Performance Energy Calculator: as the Additional Lighting Power is declared, it is added to both the baseline and the design. Therefore the gap between the design and baseline lighting power is not mitigated...so, what is the rationale behind the Additional Lighting Power, if not levelling the baseline to the design?
Furthermore, being the Additional Lighting Power in my case 1000 W + 15 W/m2 * shop window area, in the Minimum Performance Energy Calculator, only the 15 W/m2 are actually added to the maximum allowance at the end of the sheet, why not the 1000 W?
Best regards, thanks in advance
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
January 23, 2024 - 6:02 pm
The reason that the additional allowance is modeled identically is that display lighting is considered a process load, not a regulated lighting load. If the proposed general lighting design is higher than the baseline then you should be paying a penalty for that. So the purpose of the additonal allowance is not to increase the baseline up to the proposed. Not sure about what is happening in the MEPC. All of the addtional allowance should be process and modeled identically.