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It's been a few years since I last worked on an Appendix G calculation for LEED, but I don't recall any sort of credit. After skimming through the latest edition of 90.1, it still doesn't appear that there is one. I've got a few other thoughts, forgive me if you're familiar with the concepts already or if I'm talking too simply.

• Make sure that you're using what you think your system's actual maximum operating condition will be, which may differ from what's scheduled. That is, the older PMs where I worked would throw a lot of slop (a technical term, obviously) on pump head sizing calculations to keep from getting burned down the road. However, in my model's design head I'd consider the pump head calculations without the liability-insurance-safety-factor on it. So, think about what you think the head will be operationally. (Analogous to the difference between load and energy calculations, I'd say)
• I'd take full credit for what I knew about "my" system versus the App G system to squeeze what I could out of it...
• The situations where the App G pump would ride the pump curve rather than have variable speed
• The VFD curve packaged in the energy simulation software versus the actual curves from the specified manufacturer
• Make sure the pump minimum turndown on your system isn't too high, check your chiller/tower GPMs vs time to see if they make sense, etc.

I'll admit that a good portion of the work I did was big ground-coupled heat pump systems, so the pumping energy tended to kill us regardless.

Not sure if any of this helps, but good luck!

It's been a few years since I last worked on an Appendix G calculation for LEED, but I don't recall any sort of credit. After skimming through the latest edition of 90.1, it still doesn't appear that there is one. I've got a few other thoughts, forgive me if you're familiar with the concepts already or if I'm talking too simply.

• Make sure that you're using what you think your system's actual maximum operating condition will be, which may differ from what's scheduled. That is, the older PMs where I worked would throw a lot of slop (a technical term, obviously) on pump head sizing calculations to keep from getting burned down the road. However, in my model's design head I'd consider the pump head calculations without the liability-insurance-safety-factor on it. So, think about what you think the head will be operationally. (Analogous to the difference between load and energy calculations, I'd say)say) edit: to clarify, talking about a variable speed pump in this situation
• I'd take full credit for what I knew about "my" system versus the App G system to squeeze what I could out of it...
• The situations where the App G pump would ride the pump curve rather than have variable speed
• The VFD curve packaged in the energy simulation software versus the actual curves from the specified manufacturer
• Make sure the pump minimum turndown on your system isn't too high, check your chiller/tower GPMs vs time to see if they make sense, etc.

I'll admit that a good portion of the work I did was big ground-coupled heat pump systems, so the pumping energy tended to kill us regardless.

Not sure if any of this helps, but good luck!