Engineers Overcome Installation Challenges for Hospital's New Cooling Tower
NYC Health + Hospitals, The LiRo Group, and the New York Power Authority (NYPA) have completed the installation of an antimicrobial cooling tower in New York City. The specially designed cooling tower was installed on the roof of NYC Health + Hospitals/Lincoln in the South Bronx. As owner’s representative for NYPA, The LiRo Group managed the entire design and construction process for the system.
NYC Health + Hospitals/Lincoln is a full-service acute care hospital. The hospital’s Level 1 Trauma Center is the busiest in the northeast with 144,000 emergency department visits and 550,000 clinic visits each year.
The new tower not only supports the air conditioning system but offers antimicrobial features that significantly reduce the risk of harmful bacteria that sometimes grow in less advanced cooling towers. The new cooling towers replace ones that had reached their expected end of life. While the old system never contributed to any health concerns, leaders at the hospital nevertheless saw an opportunity to increase protections.
“The $11.5 million project incorporated installation of both the new cooling tower and a new energy-efficient roof,” said Luis M. Tormenta, P.E., LiRo’s CEO and vice chairman. “The old cooling tower and roof were original to the building, which was built in 1972. The new equipment and roofing materials provide NYC Health + Hospitals, NYPA, and the Lincoln facility itself with an incredibly efficient, cost-saving, and ultra-reliable infrastructure. The new cooling system is expected to lower the energy cost by 40 percent in comparison to the operational costs of the retired system.”
“Our old towers used large 48-hp fans on each unit, which required the use of a lot of electric power,” said Louis Iglhaut, associate executive director at NYC Health + Hospitals. “The new modular units are equipped with smaller 5-hp, 18-inch fans, so the energy consumption is far less. We also installed VFDs, which increase energy savings.”
The model selected prevents or impedes the growth of bacteria, including Legionella, which can cause a type of pneumonia commonly known as Legionnaires’ disease. The shells within the towers that hold the water are infused with an antimicrobial resin — wide-spectrum additives that operate on a cellular level to continuously disrupt and prevent uncontrolled growth of microorganisms and biofilm.
Another major appeal of the model was the promise of energy savings. To meet the city’s mandate to save on energy, the hospital teamed up with the NYPA, a state power organization dedicated to energy-efficient infrastructure. NYPA retained The LiRo Group, a U.S. engineering, technology, and construction management firm based in Manhattan and Syosset, New York, to oversee the project as owner’s representative.
The new cooling tower is composed of 24 model TM-605412 units by Delta Cooling Towers, organized in three sections with a cooling capacity of 1,692 tons per section. The tower provides a cooling capacity of approximately 5,076 tons total. Before this project started, the hospital had five units with a total capacity of 5,000 tons. Due to its efficiency, the new system will provide an annual energy use saving of approximately 239,376 kW, which represents savings of $26,332 per year.
At almost no time could Lincoln be without operating air conditioning. In fact, the hospital uses air conditioning a full 10 months out of the year. The first part of the construction process was to take down the old cooling tower. This had to be done in sections due to the size of the old units. As they were made of metal, the team disassembled the units using saw blades and torches. LiRo phased the project in such a way that there were only a couple of selected and predetermined hours when there was no air conditioning. This was pre-planned so that the days without air conditioning occurred in January.
Once the old tower had been fully taken down, the new cooling tower — with units made of Polyethylene (HDPE) — could be completed and activated. All sections of the new tower had to be brought up using an extremely large crane.
“The new tower had to be rigged in place 50 feet in the air with the crane. We had to do this over a period of several days,” said Marco Barbosa, LiRo project executive. “We had the tower delivered in three modules, each module with six units. We lifted one unit at a time for a total of 18 picks.”
The LiRo team put various measures in place to ensure patient safety. For example, each unit weighed 4,000 pounds and had to be lifted 50 feet up in the air and onto the roof with numerous people and emergency vehicles typically coming and going below and around the crane operation. Therefore, LiRo orchestrated a series of street closures to ensure the safety of those going into and coming out of the hospital.
According to Christopher Lynch, LiRo’s project manager, “Several nearby structures added to the logistical challenges. For example, the hospital’s heating and cooling plant is a five-story structure located next to the emergency department. Rigging the pipes and other equipment into place five stories up when you have a very busy ED was challenging, so we had to carefully plan all operations in minute detail and well in advance.”
The construction team also had to be exceedingly careful when scheduling the deliveries of equipment and materials onto the site, as Lincoln’s emergency department could at times have up to 20 ambulances coming in each hour. At no time could construction vehicles block access to the ED. LiRo had six flagmen on duty to help direct human and vehicular traffic. Due to LiRo’s planning and safety precautions, the project was completed on time and without any safety incidents.