Installing a Complete Variable Speed Drive System Proves Cost Effective for NYNEX

With 11,000 employees and very sensitive telecommunications equipment at its Buffalo, New York, facility, NYNEX needed a cost-effective heating, ventilating and air conditioning (HVAC) system to maintain a comfortable air environment and good indoor air quality. Installing variable speed drives to communicate with its central building automation control system helped NYNEX improve system performance and reduce maintenance time and energy consumption.

A global communications and media company, NYNEX provides wireless communications, directory publishing, video entertainment and information services across the northeastern United States and select markets around the world. In August 1997, NYNEX merged with Bell Atlantic to become North America's second-largest telephone company, controlling 40 million phone lines from Maine to Virginia.

At 350,000 square feet and 16 stories high, the Buffalo office is the largest NYNEX facility in western New York. The complexity of the NYNEX facility made maintaining temperature, humidity and air quality difficult and time-consuming.

"Our primary concern," said Dennis Bienias, a watch engineer at NYNEX, "was to keep the sensitive electronic and switching equipment fully operational while providing a cost-effective and comfortable working environment for our employees. NYNEX has a unique situation because we need to keep the air especially clean to support the telecommunications equipment. Dirt and dust are a real hindrance to the performance of a telephone switch."

Recognizing the need for proper environmental support to avoid system problems, NYNEX employed the services of Robson & Woese, Inc., a consulting engineering firm to upgrade to the HVAC system through a three-step process.

Step One: Choosing Variable Speed Control

The HVAC system at the Buffalo facility consists of a ventilating system on each floor of the building that provides both comfort for the employees and the proper environment for the telecommunications equipment. Comfort is provided by a central chilled water system with chillers, air handling units and centrifugal pumps, all prime movers for the HVAC system.

NYNEX chose to add variable speed drives to its centrifugal pumps and fans to help reduce operating and maintenance costs while enhancing the desired comfort level for employees. Variable speed drives adjust the fan and pump speeds to maintain the desired comfort level. As the comfort level in a room approaches its set point, the drives on the fans reduce the airflow to the conditioned areas, reducing drafts and sound while using less energy. Variable speed drives allow NYNEX improved control over the system while reducing operator involvement.

Step Two: Installing a Central Control System

While the addition of variable speed drives helped reduce HVAC costs for NYNEX, the issues involved in maintaining a HVAC system at a large facility continued to challenge the maintenance staff. NYNEX watch engineers needed to walk to each individual area of the building to monitor HVAC functions and applications. Doing so resulted in a significant amount of time spent traveling to each area to view applications and determine system problems.

To help with this concern, NYNEX installed a Johnson Controls Metasys® system as its facility management system to control the HVAC applications throughout the building. Metasys allows NYNEX watch engineers to monitor, measure and manage all HVAC applications from one centralized location. Ultimately, the new building automation control system allows NYNEX to pinpoint problems quickly and reduce overall maintenance response time.

The new Metasys system was easily integrated with existing HVAC equipment made by other manufacturers, such as air handlers, chillers, pumps, fans and drives. Because Metasys could integrate with existing equipment, the overall cost for the new system upgrade was greatly reduced.

Step Three: Integrating a Complete Variable Speed Drive System

Although the new building automation control system provided NYNEX maintenance staff with greater control of the entire HVAC system, it alone did not allow them to view and store data for each application. NYNEX was faced with the problem of finding Metasys-compatible products that would allow it to utilize full capabilities of the system.

Shortly after installing the Metasys system in the early 1990s, NYNEX began adding new air handlers to its HVAC system as old fans needed to be replaced and as needs changed. With the need to upgrade to new air handlers came the need for state-of-the-art variable speed drives.

NYNEX had been using Reliance® variable speed drives throughout the facility for almost five years. With the introduction of the Reliance VTAC 7#174 Metasys-compatible variable speed drive, NYNEX decided to continue to use Reliance drives for the newer applications.

The VTAC 7 provides interface capabilities that allow NYNEX to integrate a user-friendly and comprehensive variable speed drive interface. Now, with only a small communications card, the VTAC 7 is compatible with the Metasys system and can be connected to the system network via a communications cable.

Accomplishing Key Objectives

"Providing comfort for our employees, maintaining clean air for staff and critical equipment, and lowering operating costs were our main objectives when we started," said Bienias. "With our building automation control system, we needed to have connectivity to the drives as well. Interoperability was very important to us; no matter how it was done or who did it, that was the key for NYNEX."

The VTAC 7's compatibility to the Metasys system gives NYNEX watch engineers the ability to communicate directly with the drive, view information, monitor and assess more than 100 drive parameters from one central location without leaving the operator's work station.

The drive works with the central control system to provide trend analysis of fan motor speed, current, voltage and kilowatt consumption of each drive. Together, this information can be used for data logging information and trending calculations to inform watch engineers of impending system problems before aberrations occur. This information also can be stored in the system to be analyzed or referred to at a later time.

In addition, this system allows service technicians to connect directly to the VTAC 7's RS-232 port while running on the Metasys Control System. This is very helpful for more comprehensive drive diagnostics, which also can be directly accessed and transmitted over the Metasys system. By using Reliance communications software, variables can be charted in real time and analyzed without altering the control system.

With the advanced communication capabilities of the new building automation control system, NYNEX has safeguarded against system delays and downtime, improving the system's value and reducing life-cycle costs. By foreseeing system problems, the new variable speed drive system reduces maintenance time and saves NYNEX money.

The addition of variable speed drives also has helped reduce the number of complaints received from employees regarding drafts and air comfort issues in the offices. "We have found that we can maintain a more comfortable environment for the people we are concerned about here. The VTAC 7 drives do a very nice job for us and they work very, very well for our application," said Bienias.

As the Buffalo facility continues to expand, NYNEX will continue to evaluate equipment on a case-by-case basis. While the current system has provided the facility with the features it requires, that criteria will be regularly re-evaluated. By doing so, NYNEX can be assured that it is receiving the most cost-effective solution for all applications.

Integration of the new systems has helped NYNEX reduce costs and time spent on system upkeep and maintenance. Integrating equipment to work as one system was necessary to improve the overall performance of both the HVAC system and maintenance staff in the most efficient manner.

Editor's Note: T.P. Woodside, Inc. worked with Robson & Woese, Inc. and NYNEX personnel on this installation project.

Metasys is a registered trademark of Johnson Controls. Reliance is a registered trademark of Baldor. VTAC 7 is a registered trademark of Baldor.

Reprinted with permission from Heating/Piping/Air Conditioning, January 1998.