Precise temperature control

System Issues and Challenges

Temperatures out of range

A laboratory load requires 120 gpm [7.6 L/s] of water entering the process at 85°F [29.4°C] and returning at 95°F [35°C]. The accuracy required is more precise than the cooling tower can provide. The selected chiller has adequate capacity, but a maximum leaving-chilled-water temperature of 60°F [15.6°C].

Using a pair of bypass pipes allows the mixing valve to supply the proper temperature to the process load and maintains acceptable water flow rates and temperatures through the chiller. In the example shown in Figure 52, the chiller and process flow rates are equal, although this is not a requirement. For example, if the chiller had a higher flow rate, more water would bypass and mix with the warm return water.

Figure 52. Temperatures out of range for equipment

		60°F [15.6°C]
60°F [15.6°C]		35 gpm [2.2 L/s]
120 gpm
[7.6 L/s]			Mixing
		60°F [15.6°C]	Mixing
		60°F [15.6°C]	Valve
		85 gpm
		[5.4 L/s]
Chiller	70°F [21.1°C]		Bypass
Chiller	70°F [21.1°C]		Pipes
	120 gpm		Pipes
	120 gpm
	[7.6 L/s]

85°F [29.4°C]

120 gpm [7.6 L/s]

Constant Volume

Pump

95°F [35°C]	Process
85 gpm [5.4 L/s]	Load

Constant Volume	95°F [35°C]	95°F [35°C]
Pump	35 gpm [2 .2 L/s]	120 gpm [7.6 L/s]
120gpm [7.6 L/s]

An example of a process application layout where the required temperature control tolerance is more precise than the chiller controls allow is shown in Figure 53.

For example, when Chiller 2 is turned on, it takes a certain amount of time to reach its supply-temperature setpoint. The dedicated control valve remains closed and water is bypassed until Chiller 2 reaches its setpoint, which keeps the water temperature supplied to the process within tolerance. When Chiller 2 reaches its setpoint, the control valve opens.

This design requires a different chiller-sequencing strategy than the standard decoupled system. Water must not be allowed to bypass from the return side to the supply side, since this will cause the temperature of the water supplied to the process to vary outside the tolerance. Set the system controls to turn on Chiller 2 before deficit flow occurs.

SYS-APM001-EN

Chiller System Design and Control

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.

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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.

Trane SYS-APM001-EN manual System Issues and Challenges Temperatures out of range

Models: SYS-APM001-EN

System Issues and Challenges

Temperatures out of range

Figure 52. Temperatures out of range for equipment