Friends,
???????? We are simulating a 63 floor (900 ft tall) building with campus chilled water using the performance rating method for?LEED. We are following the directions of "Required treatment of district thermal energy" guidelines.

One of the requirements of Appendix G is to limit the pumping power to 22 W/GPM. This gives us a head of about 85 ft based on a 72% combined motor-mechanical efficiency.

If the building used onsite chillers, the W/GPM limitation is probably justified considering we could locate chillers on mechanical floors at different levels and limit the pump head. However I am not sure if this limit is justified?for campus chilled water where the water needs to be pumped from bottom up.

I found this post in the archive which seems to address this issue
http://lists.onebuilding.org/htdig.cgi/bldg-sim-onebuilding.org/2003-December/001349.html

Can anyone please comment on their experience of this situation.
?
thanks,
raj