This project involves the construction of a new refrigerated freezer warehouse. The overall facility is 140,000 sf. 105,000 sf is a -10 degree F freezer space, and the remaining area a +45 degree F freezer truck dock. There is a small office area, as well as support and maintenance areas. The facility operates as a distribution warehouse. Shipping and receiving logistical staff occupy the building. An automated material handling system means no people are in the freezer portion of the building. The facility is staffed 10 hours per day, 5 days per week; the refrigeration systems run continuously. A CIR was submitted on January 4, 2008, and responded to on February 4, 2008 for an earlier project being planned by the same building owner. This CIR builds on the previous response, and also raises some new questions. In the previous CIR, we defined a set of baseline parameters for areas not covered by 90.1 and indicated sources that support these assumptions. The reviewer requested specific documentation regarding baseline parameters and “industry standard practice”. Baseline Design In the previous CIR, the choice of refrigerant, compressor type, and capacity control method were based on “Customer’s Standard Practice”. The reviewer asked for more justification. Please confirm that the following will be acceptable. Refrigerant The baseline refrigerant in the previous CIR was R-22, although ammonia may be more widespread in facilities this size. However, the densely populated location and the local codes at the new site would require 24/7 certified ammonia operators. As the building will be staffed 10 hours, M-F, a 24/7 operator is not viable. The proposed building will use R-22 for these reasons. Can an R-22 system be the baseline? We will provide copies of the appropriate local regulations or other documentation to support this baseline assumption. Compressor Type and Capacity Control We are requesting confirmation that a letter from the refrigeration contractor stating that the customer’s choice of single stage rotary screw compressors with slide valve control to be industry standard practice is acceptable documentation. Automation within the Warehouse One of the most innovative aspects of the facility’s proposed design is fully automated material handling in the freezer. All the customer’s other facilities use regular forklifts. The automated material handling system provides energy benefits including reduced plug and infiltration loads. The greatest impact, though, is that the warehouse will be dark unless maintenance or repairs are required. We are requesting confirmation that it is acceptable to use a baseline that assumes human-driven forklifts, and that the warehouse would be equipped with fixtures that have a lighting power density according to AHSRAE 90.1 and operate on a schedule that is defined by usage of the warehouse. The proposed case energy model would be based on “lights out” operation. This saves refrigeration energy as well as lighting energy. In the office space, we will model occupancy sensors based on the 10% reduction in Appendix G Table 3.2. In the freezer truck dock, we will model the lighting as being controlled by an identical schedule in both the baseline and proposed designs. However, we are contending that a completely automated warehouse goes beyond occupancy sensor control, and are requesting confirmation that we are not limited to the 10% lighting reduction described in Table 3.2. Documentation will support the baseline assumption of an occupied, lighted freezer, and also show that the equipment in the proposed design will operate without the regular use of lighting fixtures.
The applicant is requesting the following as it relates to the certification for their refrigerated warehouse: 1 - Can an R-22 system be used as a baseline? 2 - Confirmation that a letter from the refrigeration contractor stating that the customer\'s choice of single stage rotary screw compressors with slide valve control to be industry standard practice is acceptable documentation. 3 - Would it be fair to state that a completely automated warehouse goes beyond occupancy sensor control, and are requesting confirmation that they are not limited to the 10% lighting reduction, and whether the proposed case may be modeled with the "lights out" operation. On #1, using an R-22 system as a baseline: You may not use refrigerant type as an efficiency measure. On #2, confirmation that a letter from the refrigeration contractor stating that the customer\'s choice of single stage rotary screw compressors with slide valve control to be industry standard practice is acceptable documentation: A letter from a refrigeration contractor who will be providing the equipment/services for this project does not comprise sufficient documentation of industry standard practice. Documentation should be based on a study or survey or publication from an industry association. On #3, whether a completely automated warehouse goes beyond occupancy sensor control, and not being limited to the 10% lighting reduction, and whether the proposed case may be modeled with the "lights out" operation: Yes, the proposed case can be modeled with the "lights out" operation provided sufficient supporting documentation is submitted, to the satisfaction of the project certification review team. It is recommended that any savings associated with the automated operation in the proposed design are documented through the use of an exceptional calculation method (since schedules must be identical for both the baseline and proposed design, unless otherwise stated). If credit is taken for measures including but not limited to lighting power density, occupant density, or equipment power density, please provide sufficient justification in the submittal. Finally, the process loads should be modeled based on the proposed design\'s actual power requirements as stated in the LEED NC Reference Guide, page 181, under the Process Energy section. The baseline process loads should be identical to those in the proposed design. Applicable Internationally.