Rating System

LEED BD+C: New Construction

Rating System Version

v2 - LEED 2.2

Inquiry

Clarification is requested for energy modeling protocol on a lab building which is 44,000 sf in area. An energy model was done based on Laboratory Modeling Guidelines using ASHRAE 90.1-2004 Appendix G. (http://www.epa.gov/lab21gov/pdf/ashrae_appg_draft_508.pdf). In previous CIRs (5/11/2005) earlier versions of these guidelines have been accepted in creating Baseline building models, except for calculating fan energies. Also, LEED for Laboratories Application Guide (Draft) states that the guideline may be used for energy modeling purposes. The project team, however, recently came across a CIR ruling dated 3/4/2008 that these guidelines may not be used. We would like to confirm: 1. If the Laboratory Modeling Guidelines using ASHRAE 90.1-2004 Appendix G can be used to create the Baseline building model for our project? If not: 2. Per CIRs dated 11/3/2006 and 2/26/2007, the Baseline system should be representative of a typical system. Since Systems 3 & 4 (ASHRAE90.1 Table G3.1.1A) would not be suitable for a lab with 100% outside air requirements in Houston,TX, can we use System 5? 3. Per CIR dated 8/13/2007, can we use a min. flow ratio of 50% for our baseline-supply and baseline-exhaust, both? 4. Per CIRs dated 12/21/2004,2/4/2004,12/15/03(EAp2) fume hoods should be treated as process loads. In our project, it would be impossible to isolate the energy from these as they are synchronized with the supply VAV boxes, and are occupancy driven. In this context, they aid in modulating outdoor air levels and comfort ranges for occupants and hence cannot be treated as process loads. Can we let the fan energy associated with exhaust be part of overall ventilation energy? 5. Equipment power density for lab areas is taken at 8.0W/sf in both Proposed and Baseline models, referring to the typical value from Laboratories for the 21 Century:Energy Analysis. Is this acceptable?