System Design Options

performance of this coil when it is selected with a 44°F [6.7°C] entering fluid temperature and a 10°F [5.6°C] fluid temperature rise (ΔT). To provide the required 525 MBh [154 kW] of cooling capacity, the coil requires 105 gpm [6.6 L/s] of water.

The right-hand column shows the performance of same coil, but in this case it is selected with 40°F [4.4°C] entering fluid and a 15.6°F [8.7°C] ΔT. To provide the equivalent capacity, the coil requires only 67.2 gpm [4.2 L/s] of water.

Table 9. Impact of supply temperature and flow rate on cooling coil selection

 

“Conventional”

“Low flow”

 

system design

system design

 

 

 

Coil face area, ft2 [m2]

29.01 [2.69]

29.01 [2.69]

Face velocity, fpm [m/s]

448 [2.3]

448 [2.3]

 

 

 

Coil rows

6 rows

6 rows

 

 

 

Fin spacing, fins/ft [fins/m]

85 [279]

85 [279]

 

 

 

Total cooling capacity, MBh [kW]

525 [154]

525 [154]

 

 

 

Entering fluid temperature, °F [°C]

44 [6.7]

40 [4.4]

 

 

 

Leaving fluid temperature, °F [°C]

54 [12.2]

55.6 [13.1]

 

 

 

Fluid ΔT, °F [°C]

10 [5.6]

15.6 [8.7]

 

 

 

Fluid flow rate, gpm [L/s]

105 [6.6]

67.2 [4.2]

 

 

 

Fluid pressure drop, ft H2O [kPa]

14.0 [41.8]

6.3 [18.8]

 

 

 

By lowering the entering fluid temperature, this coil can deliver the same cooling capacity with 36% less flow, at less than half of the fluid pressure drop, with no impact on the airside system.

Cooling-tower options with low flow

Smaller tower

Like coils, cooling towers are heat exchangers—although often misunderstood heat exchangers. The tower exchanges heat between the entering (warmest) water temperature and the ambient wet-bulb temperature. Therefore, in a new system or when a cooling tower is replaced, a low-flow system design allows a smaller, more efficient cooling tower to be selected. How is this possible?

Keep in mind that a cooling tower is not limited to a specific tonnage. A cooling tower is a heat exchanger that exchanges heat between the entering water temperature and the ambient wet bulb. By varying the flow or the temperature, the tower capacity can be changed—often increased.

Since the amount of heat to be rejected, Q, is approximately the same in standard-rating-condition and low-flow systems, we can estimate the heat exchange area necessary to reject the heat:

34

Chiller System Design and Control

SYS-APM001-EN

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Image 40
Trane SYS-APM001-EN Cooling-tower options with low flow, Smaller tower, System design, Entering fluid temperature, F C

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.