by Joseph Sanchez
The Encarta Dictionary of North America defines the word “feat” as a remarkable act or achievement involving skill and determination. When describing the plumbing renovations conducted in the east and west towers of Hyatt Regency Chicago, a feat is the only word that best describes this project.
Hyatt Regency Chicago is the largest hotel in Chicago and the largest Hyatt in the world. It is situated just off the world famous Magnificent Mile and within walking distance of the city’s most exciting shopping, dining and nightlife. Amenities include 228,000 square feet of flexible functional meeting space that includes four ballrooms, 63 meeting rooms and a 70,000 square foot exhibit floor.
The hotel recently underwent a massive $90 million renovation that focused on both the west and east towers. Renovations included redesigning the water supply system, re-piping 40 levels of each building and modernizing 2,019 rooms, while reducing consumption demands on water and electricity. The significance of the work lies with the speed in which it was accomplished. Both tower renovations began in a fourth quarter and were completed by the end of the following first quarter. Again, feats only accomplished by skill and determination.
The east tower of Hyatt Regency Chicago sits across the street from the west tower and was the second phase of a two-phase project. The west tower completed during the first phase in 2010.
The 36-year-old existing water system in the east tower never worked efficiently according to Dennis Sartain, project executive and vice president of Abbott Industries, headquartered in Bensenville, IL. Sartain oversaw the project from design throughout construction and was a main factor in its 12-week completion.
“There were many deficiencies in the existing system that reduced the efficiency of the building,” said Sartain.
Those deficiencies included unequal hot and cold water to room fixtures and waiting for hot water to arrive to a fixture, which was related to the original zone design that had three zones spread over 40 floors, requiring a reconfiguration of three zones.
According to Sartain, the problem was the mid-zone because its water supply pressures (Hot and Cold) could not stay balanced. The hot and cold water pressure reducing valves were located at opposite ends of the supply risers and had a significant pressure differential between the hot and cold supply pressure to that zone.
To understand the magnitude of the situation one needs to look at the numbers. There are over 1,053 rooms spread over 31 floors in the east tower. Assuming that each room has three fixtures, that would be a minimum of 3,159 fixtures not including the ballrooms, kitchens, service areas, etc. Water consumption is an enormous budget line item for a hotel this large and prestigious. When each hotel guest lets the tap run for only a few minutes waiting for hot water to arrive, the hotel will spend substantial dollars on wasted water and energy.
This was a total renovation of en existing building’s domestic water pump system, PRV stations and express risers, local risers and branch piping, without the guests ever knowing. Typically this is a task that teeters on the impossible, but with an intricate plan the impossible was realized.
So how does one re-pipe 40 levels of building, replace a domestic water pump system and PRV stations without ever terminating existing water service and without inconveniencing hotel guests?
Sartain had a plan that was clever and unique. While looking at the original drawings for the Hyatt’s east tower he noticed an existing garbage chute that was not being utilized. After further investigation he realized that he could use the abandoned chute to run his express risers, eliminating the need to tear the hotel apart. Once the plan was formed, officials at Hyatt Regency Chicago agreed to move forward on the total renovation, knowing the inconvenience would be minimal.
“This was a once in a generation opportunity to fix a problem once and for all that plagued the property for 36 years,” said Sartain.
So while work was being done on the west tower the plan for the east tower was formulated. The day the west tower was completed, work seamlessly began on the east tower. Working together with Metropolitan Industries of Romeoville who served as the equipment supplier; Tom Feilen, senior director of engineering for Hyatt Regency Chicago; Electrical Contractor Steve Wierema of Continental Electric; and Scott Stalcup of Babco Construction, Sartain and his team, which included Eric Evans, project manager, Terry Davis, project superintendent, implemented the plan.
Domestic Water Pump System
While the express risers were being installed through access hatches located on various floors of the building, the domestic water pump system was addressed. The new triplex booster system, variable speed control system and the pressure reducing zone valves were all supplied by Metropolitan Industries and replaced the 36-year-old original constant speed system that had been field modified with Variable frequency drives but used out-dated technology.
The new variable-speed, triplex domestic water booster system consisted of three 50-HP vertical multi-staged pumps, each rated 300 gallons a minute (GPM) at 428’ of total dynamic head and a system pressure of 200 PSI with a total system capacity of 900 GPM. The new booster system uses 1/3 less power than the constant speed system saving the building owners money on energy costs while reducing maintenance costs. Two 119-gallon bladder tanks were installed as well in the top floor mechanical room for low flow shut-down and stabilization of building pressure.
The new booster system is controlled with Metropolitan’s patented variable speed controller known as the Metro-Tech II. The Metro-Tech II integrates all pump operation and displays information on its color user interface. Operators can change set points, view real-time operating conditions, view integrated help screens and view alarms using its color touch screen interface.
The building is divided into three zones to stabilize pressure. There is a commercial level zone, a mid level zone and high level zone. At each zone, pressure reducing valve stations maintain each of the zone’s pressure requirements and the two 119-gallon bladder tanks installed in the top floor mechanical room help to sustain constant pressure to all zone’s regardless of building flow demands.
Using bladder tanks at the top of the express riser stores pressure so the system can shut off during low flow periods. As flow is consumed the pump system will activate and supply water to the building at the desired pressure. Once the demand for water is reduced to a low flow period, the system will shut off once again. Significant energy savings is realized during low flow periods when using variable speed drives and bladder tanks in combination.
Water Savings Astounding
With the installation of new plumbing risers, properly designed PRV stations, the new variable speed domestic booster system and water efficient fixtures, Hyatt Regency Chicago has seen a reduction in 2010’s water consumption of 16.5 %, a savings of 17 million gallons of water when compared to 2009. Once the east tower comes fully online with the already renovated west tower in first quarter 2011, the water savings should double.