I just took over an older apartment building and have been going through all the systems and equipment.
When I got to the chiller, I found a 60ton Multistack with a 500gpm evaporator pump at 11ft/hd and a condenser pump at 442gpm at 80ft/hd, this raised a flag so I contacted Multistack. This chiller is designed for 190gpm at 6.5psi on the evaporator and 230gpm at 9psi.
Needless to say I can not get the system to run down to 45 degrees nor get the proper temperature rise on the condenser.
I am curious from those who understand more about fluid and thermo dynamics, what problems/issues are happening due to this lack of engineering. I know that the water is moving to fast to achieve the proper heat transfer, but is there more beyond that?
One other question, when pumps are piped in series, is the GPM added and the head whichever is larger?