With more than 33,000 square feet of meeting space, the 231-room Marriott Northwest Hotel and Conference Center is one of the top conference hotels in the Twin Cities area in Minnesota. In 2011, the previously independent hotel underwent an extensive US$24 million renovation to its interior and exterior before becoming part of the Marriott brand and in order to reclaim the 21-year hotel’s prominence in the marketplace.
One of the most significant aspects of the project was the modernization of the building’s four hydraulic elevators, which were replaced with the newest energy-efficient and oil-free technology and produced dramatic improvements to hotel guests’ experiences.
Aging elevators
Originally built and designed in 1989 by John Q. Hammons, one of the nation’s premier developers, the hotel features his signature style with an open atrium and glass-backed elevators. The four hydraulic elevators (“hydros”) installed during construction were wrong from the start, given the building’s height and the frequent use of the elevators, and placed immense demands on the cooling of the system. In fact, the building contained the tallest hydraulic elevators west of the Mississippi river.
Years later, Brian Madison, Facility Manager for Marriott Northwest said, “I was very surprised to see hydraulic elevators in a building of this size. I had seen them in three to four-story buildings, but never in an eight-story one.”
As the elevators aged, their deficiencies became more apparent, causing inconveniences for hotel guests. For one, the elevators were slower than those of other hotels. A non-stop trip from the lobby to the eighth floor took two minutes and thirty seconds, a painfully long travel time for guests. Furthermore, the elevators were loud due to the leakage of air into the hydraulic pump. While not a safety issue, the noise did cause unease for riders and guests. However, more noticeable was the elevators’ smell. On high-traffic days, the elevators’ oil would heat up, emitting an odor noticeable from the machine room to the inside of the cab and other nearby public spaces.
The hotel owners were also concerned about the environmental issues posed by the hydraulic elevators. Due to the use of hydraulic fluid, aging hydros are commonly at risk of hazardous materials that can be leaked and spilled, contaminating the surrounding area with dangerous, toxic chemicals. Additionally, as hydraulic elevator systems age, oil leaks cause them to be increasingly inefficient. The pump also works against gravity to push the car and its passengers upward making it less energy efficient than other models, particularly in low-rise buildings. Not only were these inefficiencies environmentally troublesome, they often also resulted in high energy costs for the hotel caused by older, inefficient motors.
In addition, elevator control technology has dramatically improved since 1989, following the rise of computers throughout all industries. The hotel’s original elevators featured PM logic, with electrical relays and yes/no binary inputs. By modernizing its elevators, the hotel could take advantage of modern controllers using computer logic.
Modernization solution
As a result of these issues, the hotel began talks for a solution that would replace the building’s outdated technology with the latest, most efficient and sustainable elevators, while meeting some of the challenges the building presented. First, the modernization project had to keep the glass-back elevators that the original design demanded. Not only were the glass-back elevators integral to the aesthetic of the atrium, but they were popular with hotel guests. The building would also need to stay open during construction. A final challenge was that the building’s height exceeded the travel limitations of the new, proposed elevators.
In the end, the hotel owners were able to overcome these challenges with a custom solution that allowed the hotel to replace its four hydraulic units—two eight landing and two nine landing—for energy-efficient machine room-less elevators. The elevators would provide energy savings, due in part to the transition from old 50 HP motors running continuously to 8.8 HP motors with regenerative drives; features which capture energy created by downward operation and feed it back into the building’s energy supply. Use of a regenerative drive alone can recover up to 25 percent of the total energy used by an elevator.
The solution also included new permanent-magnet, gearless motors, which weigh less than half of those of conventional-geared traction machines and have only one moving part. These factors supported a system that was three times more efficient and used 70 percent less energy than hydraulic elevators—a savings which could come to represent half or more of the annual cost of the elevator operation.
The construction schedule enabled the building to remain open and guests to continue moving smoothly and safely throughout the building during construction. Work was done to two elevators at a time, leaving two functioning elevators to serve guests and staff during each phase of the project.
Finally, the look and feel of the previous cabs were able to be replicated with a customized solution that preserved the hotel’s unique personality while assuring efficiency, convenience and energy savings for years to come.
Exceeding expectations
The elevator modernization produced significant improvements to the flow of people throughout the building, reducing the total travel time from lobby to the top floor to 30 seconds, an 80 percent decrease. The difference is especially noticeable to people flow when the hotel is fully booked. Before the modernization, the slow elevators would cause long lines in the lobby and on each floor, as guests waited for an elevator. “With traction elevators, there is better flow during the check-in/check-out process. It’s easier for people to get to their destination within the hotel,” Madison said.
Madison has also seen a steep decrease in customer complaints due to the new elevators. Before the reduced ride times, the elevators were the source of 25-30 percent of the hotel’s complaints. Since renovation, elevator-related complaints have been reduced to almost zero.
The increased speed from the elevators has also produced savings in labor. Prior to the renovations, housekeeping and the hotel’s engineering staff avoided the elevators. With the new elevators, staff members are able to do their jobs quicker and more efficiently, because it is easier to get to their destination. Madison adds, “The modernization not only was an improvement to customer service, but it has produced labor savings as well.”
In addition to the long-term energy savings the building would now enjoy, the new elevators met a more immediate need for the hotel. Before the Northland Inn could join the Marriott brand, it needed to reduce its carbon footprint by 60 percent. The new elevators, combined with changes such as more efficient lighting, heating and cooling, allowed the hotel to exceed this target. By the end of the renovation, the hotel had reduced its carbon footprint by 70 percent.
By choosing machine room-less elevators, the Marriott Northwest was able to eliminate the environmental risks of hydraulic elevators, keep the aesthetic features integral to the hotel’s design, satisfy environmental goals and dramatically improve customer experience and staff efficiency. With sales of MRL elevators exceeding those of hydraulic elevators for the first time in history, the renovation of the Marriott Northwest serves as a great example of the growing trend toward the replacement of aging hydros and the adoption of energy-efficient technology. FMJ
