Rating System

LEED BD+C: New Construction

Rating System Version

v3 - LEED 2009, v2 - LEED 2.2

Inquiry

Our project involves a new 817,000 square feet facility for the production and storage of multiple milk-based products. The project is targeting a LEED Silver certification, which includes earning points under EAc1 for modifying the manufacturing process, improving equipment efficiency and controls. As process loads exceed "regulated" loads, it is anticipated that process energy efficiency improvements will comprise the majority of energy savings for the project. Due to the nature of the project, the following issues must be resolved in order to complete the EAp2 and EAc1 analysis: The identification of the building portions that are regulated under ASHRAE Standard 90.1-2004 The method for demonstrating that the regulated spaces meet EAp2 requirements The method for calculating energy savings under EAc1 for both the regulated and unregulated building portions Through this CIR, the team requests the acceptance of the following methods for addressing the issues outlined above. ASHRAE 90.1 Regulated Spaces The facility can be categorized into four conditioned space types and the utility plant as outlined in Table 1. Space Floor Areas and Indoor Conditions: Spaces are : Office 50,000 s.f. Ref. Warehouse 225,000 s.f. Processing 118,000 s.f. Packaging 331,000 s.f Utility Plant 92,000 s.f. Summer indoor design conditions are: Office (75F-50%), Ref. Warehouse (42F-50%), Processing (68F-50%), Packaging (80F-60%) and Utility Plant (NA) Winter Design Conditions are: Office (72F), Ref. Warehouse (42F), Processing (60F), Packaging (60F) and Utility Plant (NA) Section 2.3 of ASHRAE 90.1-2004 states that the standard does not apply to "equipment and portions of buildings that use energy primarily to provide for industrial, manufacturing or commercial processes." Process energy is further defined as "energy consumed in support of a manufacturing, industrial, or commercial process other than conditioning spaces and maintaining comfort and amenities for the occupants of a building." The team interprets this statement to mean that the standard does not apply to building portions that have indoor conditions dictated by process requirements instead of occupant comfort conditions. E.g, this obviously exempts refrigerated warehouse areas. Based on this interpretation, the team believes that the office and the packaging spaces are regulated by ASHRAE but the other spaces are not (footnote 1). EAp2 Approach To meet EAp2 requirements, the team proposes to demonstrate that the ASHRAE regulated spaces meet the energy performance requirements through a prescriptive or performance-based approach(footnote-2). Since the majority of savings anticipated under EAc1 will come from process loads occurring in the unregulated spaces, the option to show EAp2 compliance by using the results of the Performance Rating Method would not be appropriate. EAc1 Approach The following methodology is proposed for the EAc1 analysis: The EAc1 savings for the regulated building portions will be determined using the PRM without modification. The baseline model for the unregulated building portions will generally be the same as the proposed model and will be based on the schematic design documents. Process energy use in the baseline and proposed models will be calculated as noted below, and added to the respective results. As already alluded to, the process equipment uses most of the energy in this facility (e.g. the new substation service is sized at 30 W/sf). Most savings anticipated for the project will result from reducing process loads and process energy use. Since these components are not regulated under ASHRAE, an exceptional calculation method (ECM) will be followed to quantify savings. As part of this, the EAc1 submittal will include documentation of the assumed baseline system configurations and performance calculations and the same information for the proposed building. Characteristics that change between the baseline and proposed buildings will be clearly outlined as part of each ECM presentation. We anticipate that spreadsheet methods will be used to calculate most of process energy savings. Footnotes: (1) the process space has low humidity requirements that can not easily be met by the 44F chilled water temperature dictated for a baseline CHW system in the Performance Rating Method. (2) If a performance-based approach is used, the unregulated building portions will be considered to be energy neutral