Problem:
A 20 year old 30 floor apartment building was turning condo. The domestic water supply system was beginning to show its age and become unreliable. The original system was a antiquated design with bulky cast iron vertical turbines and a very inefficient recirculation system that wasted a lot of power. The pumps were at the end of their service life and were causing major supply problems. Repair parts were also becoming scarce. Those that were available had extended lead times.
Solution:
We installed a new Mack multistage centrifugal triplex pump system. We engineered and prefabricated our skid to match the existing footprint and pipe connections of the old unreliable skid so installation time and costs are at a minimum. The new skid operates on a VFD. One of the main benefits of a VFD is power consumption. By altering the speed to only run the pumps at the speed required at that instant a substantial power savings can be realized. We estimate the first year’s savings will be 40% in power savings. When the system senses usage in the system the VFD will start up a small jockey pump. It will build speed until the system is brought back up pressure. If this pump cannot maintain the desired line pressure the VFD will start to ramp up one of the main system pumps. It will continue to ramp the speed of the pump up until the pressure in the line raises to the desired point. If the pump reaches full speed before the desired pressure is reached it will switch it over to direct power and the VFD will begin to ramp up the second system pump. We’ve built logic into the system so that it can tell the difference between a catastrophic failure like a line break and normal heavy usage. If is senses anything out of the normal operating parameters the system will send a page to the building operators notifying them of the issue. The system can also be monitored and adjusted off site via the internet. | 
