ASHRAE Interpretations are considered applicable for all LEED projects using the referenced ASHRAE Standard, regardless of LEED registrations date, since ASHRAE Interpretations are considered to be clarifications of the ASHRAE standards only. However, in consideration of the long-standing GBCI review approach that allowed 22 W/gpm for each Baseline chilled water pump, this ASHRAE Interpretation which states that “the baseline pump power in Section G3.1.3.10 was developed as 22 W/gpm, and is the total wattage allowed for all cooling system pumps,” shall be mandatory only for projects registered after the publication date of this LEED Interpretation.
For projects registered after the date of this LEED Interpretation, the total Baseline chilled water system pump power shall be 22 W/gpm per ASHRAE 90.1-2007 Section G3.1.3.10; and the Baseline pump power shall be evenly distributed between the Baseline primary and secondary chilled water pumps. Alternatively, if the proposed case has primary/secondary chilled water pumps, the Baseline pump power may be distributed between the Baseline primary and secondary pumps consistent with the proposed design.