Baseline HVAC, Non-regulated loads and Exceptional Calculation Method for V4.1

LEEDuser Premium Member

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Project location :

United States

December 7, 2023

A 156,000 SF pharmaceutical production facility wants to pursue LEED v4.1. Building breakdown as follows:

75,000sf of pharmaceutical manufacturing space with 30-40 ACH and 24/7 operation
35,000sf of office space on two floors
6,000sf of laboratory at 12 ACH w/ over 15,000cfm exhaust
3,000sf of hazardous storage (1 cfm/sf)
2,000sf of hazardous chemical space (1 cfm/sf)
35,000sf of utility plant, and miscellaneous mechanical, electrical, and support spaces

We have a central chilled water plant, central hot water plant along with a central heat recovery chillers serving all spaces. Dedicated AHU’s serve respective spaces

Questions regarding the above

Is LEED coordination/pre-approval required prior to utilizing an “Exceptional Calculation Method” if the method was approved for similar past projects?
Can the 6,000sf Laboratory Baseline HVAC system be System 5 or 7 according to 90.1 App G3.1.1.d or should it be consolidated with the manufacturing space “Exceptional Calculation Method”?
1. Same question for Hazardous Storage and Chemical Space.
Should the 75,000 sf pharmaceutical manufacturing space pursue the Exceptional Calculation method to show energy savings if we can establish a standard base line system?
Depending on question 2, what is the building type with the largest conditioned floor area as to determine the HVAC system base line (predominanat condition)
Project is ASHRAE zone 3A. Per Table G3.1.1-3, the Baseline HVAC Systems for Climate Zone 3a are predominantly DX cooling and heat pump heating, except for the Laboratory System 5 (DX + HW) and the “non-regulated” Manufacturing Space (DX + HW)?
Should the regulated and non-regulated HVAC systems with CHW and/or HW coils be served by separate heat recovery plants in the Proposed Case?
How should the central heat recovery plants be sized in the Proposed Case given that the plant sizing is no longer consistent with the 100% CDs and separating the regulated and non-regulated loads may not accurately reflect heat recovery plant operation?
Depending on answer to question 2, if the SF of non-regulated loads is more than 50% of the total SF, does Credit IR # 10493 from v 4 apply to 4.1?
1. If so, can the Exceptional Calculation method still be applied to non-regulated loads?

Post a reply

Tyler Thumma

7Group

LEEDuser Expert

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Fri, 04/05/2024 - 14:12

1. No, pre-approval is not required for an Exceptional Calculation Method. It can be submitted in the Preliminary Review phase. However, note that past reviews do not set a precedent for future projects; each project receives a thorough technical review based upon information contained within the documentation submitted for review. 2. The lab spaces should be modeled with a separate System 5 or 7 according to G3.1.1 exception d. It seems like the hazardous spaces should be modeled with a separate system type from the manufacturing based on the different airflow requirements. 3. Yes 4. You would take the remaining total building area after subtracting areas where exceptions to G3.1.1 are applied, and use that area to determine the primary Baseline system type. 5. Correct 6. No, if the same plant serves both systems then it should be modeled that way. 7. N/A because the plant should not be separated. 8. The 50% process in LI 10493 is based on energy cost, not area. However, this LI is only applicable to v4.