Chilled water (without antifreeze) at 34°F (1.1°C) is possible with some chillers that use sophisticated evaporator-design and chiller-control methods.

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System Design Options

recommends a design method that starts with condenser-water temperature difference of 12°F to 18°F [7°C to 10°C].

Standard rating temperatures

Currently, the standard rating condition temperatures in ARI 550/5905 and ARI 5609 are:

•Evaporator leaving water temperature: 44°F [6.7°C]

•Water-cooled condenser, entering water temperature: 85°F [29.4°C]

•Air-cooled condenser, entering air dry bulb: 95°F [35.0°C]

For years, these temperature definitions were the benchmarks in system designs. Today, designers apply a variety of different temperatures.

ARI 550/590 reflects this trend by allowing the chilled-water and condenser- water temperatures to be selected at non-standard points and the chiller to be tested as specified by the standard.

Chilled-Water Temperatures

Currently, comfort cooling systems are designed with chilled-water supply temperatures that range from 44°F [6.7°C] to 38°F [3.3°C], and, in some cases, as low as 34°F [1.1°C]. Reasons to decrease the chilled-water temperature include the following:

•The system design more readily accommodates wider temperature differences (lower flow rates) than the standard rating conditions (see “Selecting flow rates” on page 30).

•Lower water temperature allows lower air temperatures (and flows) to be selected, resulting in reduced airside installed and operating costs.

•Colder water in the same chilled-water coil may provide better dehumidification.

•Colder water can be used to increase the capacity of an existing chilled- water distribution system. In some instances, this can save significant capital expenditures to add capacity to large central plants that have reached their flow limits.

Some system designers hesitate to use lower chilled-water temperatures, concerned that the chiller will become less efficient. As discussed in “Effect of chilled-water temperature” on page 3:

•Lower chilled-water temperature makes the chiller work harder. However, while the lower water temperature increases chiller energy consumption, it significantly reduces the chilled-water flow rate and pump energy. This combination often lowers system energy consumption.

•Lower chilled-water temperatures may require more insulation on piping to prevent unwanted condensation (“sweating”). Ensure that pipes are properly insulated at all water temperatures. Lower temperature water often does not require more insulation.

Chiller System Design and Control

SYS-APM001-EN

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Trane SYS-APM001-EN manual Chilled-Water Temperatures, System Design Options, Standard rating temperatures
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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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