Dear LEED APs,

I have a LEED CI v4 project in Taipei, Taiwan, which require whole building energy modelling. Couple of questions I hope to seek clarity:

Question 1:

The project has peak cooling load larger than 2110 kW, and noted that water-cooled centrifugal chillers, no greater than 2813 kW, are all required to be sized equally. However, do we need to use COP 6.1 for the baseline chillers (at AHRI conditions)? Or can the COP be adjusted to project's outdoor conditions? For example, under AHRI rating conditions, COP 6.1 is derived with condenser water temperature leaving cooling tower at 30 degC. But in the case of Taipei's outdoor condition, the designed condenser water temperature leaving cooling tower is 31.35 degC based on methodology detailed under G3.1.3.11. Surely, with a higher condenser water temperature leaving cooling tower, this will have a detrimental effect on the chiller's performance and corresponding COP. Will USGBCI allow project to adjust the chiller's COP in the baseline model such that both baseline model and proposed model will be simulated under project's outdoor conditions?

Question 2:

Under what circumstances can the project pursue Minimum Equipment efficiencies (listed equipment) - nonstandard conditions?

Thank you!


Andrew Xiao