System Controls

high. The control point is selected to minimize over-pressurizing the system and to assure adequate flow at all critical loads.

Critical valve reset (pump pressure optimization)

Often, pumps are controlled to maintain a constant-pressure differential at a remote coil. Unless this coil serves the zone requiring the most pressure (the critical zone), the pump provides more pressure than necessary and consumes more power than necessary. Systems that have integrated airside and chiller plant control systems and contain valves with direct digital controls present an opportunity for further pump operating-cost reduction. If a system is monitored to determine the critical valve at each point in time, the pump’s operating pressure can be reset so that the critical zone’s control valve is nearly wide open.

Integrated control allows a system-level controller to determine the critical zone and reset the pump’s setpoint dynamically, therefore reducing pump operating costs.

Air-handler controllers know the position of their individual valves, which modulate to maintain the required water flow through the coil. The building automation system continually monitors the valve controllers, looking for the most open valve. The controller resets the pump setpoint so that at least one valve, the one requiring the highest inlet pressure, is nearly wide open. The result is that the pump generates only enough pressure to get the required water flow through this “critical” valve, thus saving pumping energy.

Addendum ak to ASHRAE 90.1-2007 now requires pump pressure for many chilled water systems. It will become part of 90.1-2010.

Number of chillers to operate

Some practitioners believe that operating more chillers at the same time permits each chiller to operate more efficiently. From a system perspective, this is rarely true. The chillers are not the sole energy consumers in the plant—activating a chiller also activates the condenser water pump, perhaps a chilled water pump, and tower fans. One analysis showed that if all operating chillers are equipped with variable frequency drives (VFDs), the only time it makes sense to run more chillers than necessary is if the condenser water drops below 65°F. Without VFDs on the chillers, the system never used less energy with the extra chiller operating.

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Chiller System Design and Control

SYS-APM001-EN

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Trane SYS-APM001-EN manual System Controls, Number of chillers to operate, Critical valve reset pump pressure optimization
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SYS-APM001-EN specifications

The Trane SYS-APM001-EN is an advanced control system designed for HVAC (Heating, Ventilation, and Air Conditioning) applications, specifically tailored to enhance energy efficiency and system performance. This comprehensive solution integrates cutting-edge technologies to optimize climate control in commercial and industrial environments.

One of the main features of the SYS-APM001-EN is its intuitive user interface. The system is equipped with a large, easy-to-read display that provides real-time data on system performance, energy usage, and environmental conditions. This user-friendly interface makes it simple for operators to monitor and adjust settings, ensuring optimal comfort levels and efficient energy consumption.

Another key characteristic of the SYS-APM001-EN is its advanced data analytics capabilities. The system collects and analyzes data from various sensors throughout the building, providing insights into occupancy patterns, equipment performance, and energy consumption trends. This data-driven approach allows facility managers to make informed decisions about system adjustments, predictive maintenance, and energy savings.

The SYS-APM001-EN also boasts robust integration capabilities. It can seamlessly connect with a variety of building management systems (BMS) and other third-party devices. This interoperability enables a cohesive operational ecosystem where HVAC systems can communicate and cooperate with lighting, security, and fire safety systems, enhancing overall building efficiency.

Energy efficiency is a hallmark of the SYS-APM001-EN, as it implements sophisticated algorithms to optimize system operation. These algorithms adjust equipment performance in real-time based on current conditions, thereby reducing energy waste and lowering operational costs. The system is designed to support multiple energy-saving strategies, including demand-controlled ventilation and optimal start/stop scheduling.

Additionally, the SYS-APM001-EN is built with scalability in mind, accommodating facilities of various sizes and configurations. Whether it’s a small office building or a large industrial complex, the system can be tailored to meet specific needs, ensuring that HVAC performance aligns with operational goals.

In conclusion, the Trane SYS-APM001-EN is an innovative HVAC control solution that emphasizes user experience, data-driven decision-making, and energy efficiency. With its advanced features and technologies, it is an essential tool for optimizing building performance and enhancing occupant comfort while reducing environmental impact.
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