Global Telecommunications Provider, SHERMAN OAKS, CA
Greater energy efficiency; low-cost operation; simplified turnkey project delivery; single point of accountability; improved facility airflow and air quality; extensive system failure notification; complete integration of equipment, building control system, and application software; projected 3-year payback; non-disruptive project delivery.
To improve energy efficiency without disrupting mission-critical services; to satisfy the corporation’s 3-year payback financial criteria.
SCOPE OF SERVICES
To meet this client’s energy and financial objectives, EMCOR Services Mesa Energy Systems began by performing an energy audit and identifying ways to reduce energy consumption and costs. The result was recommendations that achieved the client’s energy and financial goals by taking a “big picture” approach that only a single-source provider, such as Mesa, can deliver in a timely and cost-effective way.
Mesa’s primary recommendation was to replace two chillers that were due for an overhaul with new, more energy-efficient units that use frictionless central processor-controlled compressors. These were the first chillers of this type to be installed in southern California. After these and other recommendations had been accepted, Mesa disconnected, removed, and disposed of the two former chillers with their refrigerants. The company also removed existing chiller water piping, and installed and insulated new piping to accommodate the new chillers’ two-pass configuration. On the electrical side, the company demolished the old conduits and wiring, and installed new components. In addition, Mesa installed seismic anchoring plates, and oversaw all crane lifting, rigging, and permitting activities.
Mesa then put in the new chillers. The installation included a new Andover Control System for the central plant. This part of the installation required extending conduits from the control panel to various temperature sensors installed on the chilled water and condenser water piping, and connecting them via BACnet to all the pump VFD’s and to the new chillers. For optimum energy efficiency, the chiller control includes lead/lag staging capability that improves performance by continuously adjusting the respective compressors to various environmental and operating conditions as well as the flow through the condenser and chilled water pump VFD’s.
The facility’s economizer system was another target for improvement. To help it regulate both room air pressure and outside air intake more efficiently, Mesa performed several key services. In addition to putting in new pre-filters and installing new racks with 100 percent more surface area, the company attached variable frequency drives with bypasses to floor exhaust fans, connected them to the building control system, modified the system’s software to accommodate this connection, tested the system, and backed up the databases. To further enable high-performance operation, Mesa experts added variable frequency drives with bypasses to the air-handling unit’s supply fans.
Mesa also added some safety features. The company’s experts integrated system failure alarms into the building control system, modified the alarm system database, and conducted testing. As part of the project, Mesa brought the facility’s refrigerant monitoring system up to local code standards by replacing the previous monitoring panel with a new one and running electrical conduit and wire to interlock the mechanical room’s chillers and pumps. This shuts down both of these devices in the event of an emergency. The company also installed horn strobes and break-glass stations with interface panels at the mechanical room’s entrances, and connected gas sensing copper tubing to the alarm panel.
To make all of this work together efficiently, the company upgraded the existing controls system. Since frictionless compressors operate most efficiently on part loads, designing controls that coordinate pumps, chillers, and other devices effectively is a highly complex task. To accomplish it, Mesa optimized the control strategy and its algorithms, enabling an all-variableflow central plant that regulates system components for maximum energy efficiency. At the same time, Mesa provided a new workstation with graphics, connected the control system to both the new and the backup chillers, and put in variable frequency drives with bypasses for the primary chilled and condenser water pumps.
Finally, Mesa unified the parts by connecting the control room modbus link to the existing modbus gateway and integrating such features as the air conditioning valve position database, critical space temperatures on each floor, and the economizer damper positions. The company also interfaced the new Andover Control System and its software to the client’s Building Environmental Control and Alarm System (BECAS), and for maximum compatibility, converted the required screens.
In today’s world, maximum energy savings result from designing a multi-faceted energy strategy that takes into account all components of a building’s system. That requires a company with the complete expertise necessary to handle everything from the initial audit and savings documentation through system design, equipment comparison and selection, permitting, and project delivery, as well as testing, commissioning, and ongoing maintenance.
This kind of single-source delivery provides expertise for knowledgeable decisionmaking during the early project stages, helping to ensure that client goals will be achieved. As the project progresses, the single-source approach saves markup costs, as well as the time spent resolving construction implementation and management issues. It also enables earlier project completion than would be possible with multiple vendors. That means immediate, rather than eventual, energy savings with new, more reliable equipment.
For more than a century, this Global Telecommunications Provider has provided a wide range of communications products and services as well as customer care.