System Configurations

Alternatively, the operating chiller can be reset to produce a lower supply temperature at this condition. In this way, the mixed system supply-water temperature may be maintained at a more acceptable temperature. This complicates the control system and presents the possibility of increasing chiller energy consumption due to the requirement for lower-temperature water. There will also be a low limit to this water temperature, dependent on the chiller’s low pressure cut-out control, low evaporator-refrigerant- temperature limits, or low leaving chilled-water limits. The more chillers in the system, the worse the problem becomes. For this reason, this configuration is seldom used in systems with more than two chillers.

Additionally, ASHRAE/IESNA Standard 90.1–2007 (Section 6.5.4.2) prohibits this type of system when the pump is larger than 10 hp [7.5 kW]. The standard requires that, in systems that contain more than one chiller piped in parallel, system water flow must be reduced when a chiller is not operating.

 

Figure 26. Parallel chillers with separate, dedicated chiller pumps

 

 

Off

 

 

 

42°F

 

 

[5.6°C]

 

On

 

 

54°F

 

 

[12.2°C]

60% to 70% of

 

 

system flow

 

Coil starved for flow

 

 

If separate, dedicated chiller pumps are used (Figure 26), a chiller–pump pair

 

can be cycled together. This solves the flow mixing problem described

 

above, but presents a new problem. Below 50-percent load, only one chiller

 

and one pump are operating. The total water flow in the system decreases

 

significantly, typically 60 to 70 percent of full system flow, according to the

 

pump–system curve relationship.

 

 

Ideally, at this part-load flow rate, all of the coils will receive less water,

 

regardless of their actual need. Typically, however, some coils receive full

 

water flow and others receive little or no water. In either case, heavily-loaded

 

coils or the loads farthest from the pump will usually be “starved” for flow.

 

Examples of spaces with constant heavy loads that may suffer include

 

computer rooms, conference rooms, photocopy rooms, and rooms with high

 

solar loads.

 

SYS-APM001-EN

Chiller System Design and Control

43

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Trane SYS-APM001-EN manual System Configurations, Parallel chillers with separate, dedicated chiller pumps
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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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