Trane RTHD Application Considerations, Variable Evaporator Flow and Short EvaporatorWater Loops

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Application Considerations

Condenser Water Temperatures Reduced sensitivity to condenser water startup temperatures is one major enhancement in the newest-generationwater-cooled Series R chiller.With the model RTHD chiller, a condenser water control method is necessary only if the unit starts with entering water temperatures below 55°F (12.8°C), or between 45°F (7.2°C) and 55°F (12.8°C), when a temperature increase of 1°F (0.56°C) per minute to 55°F (12.8°) is not possible.

When the application requires startup temperatures below the prescribed minimums, a variety of options are available.To control a 2-way or 3-way valve,Trane offers a Condenser RegulatingValve Control option for the CH530 controls.This option enables the CH530 controls to send a signal for opening and closing the valve as necessary to maintain chiller differential pressure.The 2-way valves are available as a ship-with option.Tower bypass is also a valid control method if the chiller temperature requirements can be maintained.

Trane Series R chillers start and operate successfully and reliably over a range of load conditions with controlled entering condenser water temperature. Reducing the condenser water temperature is an effective method of lowering chiller

power input required, but the ideal temperature for optimizing total system power consumption will depend on the overall system dynamics. From a system perspective, some improvements in chiller efficiency may be offset by the increased tower fan and pumping costs required to achieve the lower tower temperatures. Contact your localTrane systems solution provider for more information on optimizing system performance.

The minimum acceptable refrigerant pressure differential between condenser and evaporator is 23 psid.The chiller control system will attempt to obtain and maintain this differential at startup, but for continuous operation a design should maintain a 25°F (13.9°C) differential from evaporator leaving water temperature to condenser leaving water temperature.

Variable Evaporator Flow and Short EvaporatorWater Loops

Variable evaporator flow is an energy- saving design strategy which has quickly gained acceptance as advances in chiller and controls technology have made it possible.With its linear unloading compressor design and advanced CH530 controls, the RTHD has excellent capability to maintain leaving water temperature control within +/-0.5°F (0.28°C) , even for systems with variable evaporator flow and small chilled water volumes.

Some basic rules should be followed whenever using these system design and operational savings methods with the RTHD.The proper location of the chilled water temperature control sensor is in the supply (outlet) water.This location allows the building to act as a buffer, and it assures a slowly changing return water temperature. If there is insufficient water volume in the system to provide an adequate buffer, temperature control can be lost, resulting in erratic system operation and excessive compressor cycling.To ensure consistent operation and tight temperature control, the chilled water loop should be at least two minutes. If this recommendation cannot be followed, and tight leaving water temperature control is necessary, a storage tank or larger header pipe should be installed to increase the volume of water in the system.

For variable primary flow applications, the rate of chilled water flow change should not exceed 10 percent of design per minute to maintain +/-0.5°F (0.28°C) leaving evaporator temperature control. For applications in which system energy savings is most important and tight temperature control is classified as +/-2°F (1.1°C), up to 30 percent changes in flow per minute are possible. Flow rates should be maintained between the minimum and maximum allowed for any particular chiller configuration.

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RLC-PRC020-EN

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Contents Series R Helical Rotary Liquid Chillers Introduction American Standard Inc. All rights reservedContents Simple, Economical Installation Features and BenefitsApplicationVersatility and High Performance Operating and Life Cycle Cost-Effectiveness Reliability and Ease of MaintenanceState-of-the-Art, Precision Control Design capabilities includeOptions Programmable Relays ChilledWater Reset Outdoor Air TemperatureIce Making Control Condenser-RegulatingValve ControlAdditional Display Features Include ControlsKeeping Operators Informed Energy EfficiencySwift Emergency Response Application Considerations Variable Evaporator Flow and Short EvaporatorWater LoopsWater Pumps Water TreatmentAcoustic Considerations Part Load Performance PerformanceFouling Factors System ConsiderationsEvaporator and Condenser Pressure Drop Unit Performance with Fluid Media OtherThanWaterElectrical DataTables Model Nomenclature RTHDigit 28 Condenser Leaving Water Temperature Nominal Data General DataGeneral Data Minimum/Maximum Condenser Flow Rates Gallons/Minute Minimum/Maximum Evaporator Flow Rates Gallons/MinuteMinimum/Maximum Evaporator Flow Rates Liters/Second Minimum/Maximum Condenser Flow Rates Liters/SecondMinimum/Maximum Evaporator Flow Rates GPM Minimum/Maximum Condenser Flow Rates GPMCompressor Motor Electrical Data 60 Hertz Electrical Data ConnectionsCompressor Motor Electrical Data 50 Hertz Electrical Data and Connections Electrical Data and Connections Shipping and Operating Weights Dimensions WeightsOperatingWeight ShippingWeight Code Lbs BBB Configuration BCD Configuration Front 36 914 mm Back Either End Other EndCDE, DDE, EDE Configuration CEF Configuration CFF, DFF, EFF Configuration DGG, EGG Configuration Mechanical Specifications ConversionTable RLC-PRC020-EN Supersedes RLC-PRC020-EN-00406 Literature Order NumberFile Number PL-RF-RLC-000-PRC020-EN-0606 Stocking Location Inland

RTHD specifications

The Trane RTHD is a highly efficient and innovative HVAC solution designed for commercial and industrial applications. With a focus on reliability, performance, and energy efficiency, the RTHD series offers a wide range of features that set it apart from conventional heating and cooling systems.

One of the standout characteristics of the Trane RTHD is its robust construction. Built to withstand the rigors of daily use in demanding environments, the unit boasts a durable and weather-resistant cabinet. This design not only ensures longevity but also helps protect internal components from external elements.

Energy efficiency is at the forefront of the RTHD's design philosophy. The unit utilizes advanced technologies such as Variable Frequency Drive (VFD) for its compressor and fans. This allows for precise adjustment of the cooling and heating output, optimizing energy consumption based on real-time demand. As a result, the RTHD can achieve impressive Seasonal Energy Efficiency Ratios (SEER) and Heating Seasonal Performance Factors (HSPF), making it an environmentally friendly choice.

Another key feature of the RTHD is its compatibility with various control systems. The unit supports Trane's advanced control technology, enabling integration with building management systems for enhanced monitoring and operational efficiency. This capability allows facility managers to leverage data-driven insights to optimize performance and maintenance schedules.

The RTHD also incorporates innovative sound-reducing technologies, which ensure quiet operation, a significant consideration for settings where noise reduction is essential. Features such as acoustic insulation and strategically designed fan blades help minimize sound levels, making the RTHD suitable for a variety of commercial environments.

Ease of maintenance is another important aspect of the Trane RTHD. The design includes accessible components for quick servicing, minimizing downtime and overall maintenance costs. Additionally, Trane provides comprehensive support and resources to ensure that technicians can efficiently maintain and troubleshoot the system.

In summary, the Trane RTHD is a leading-edge HVAC solution that combines durability, energy efficiency, advanced control options, and quiet operation. With its range of features and technologies, it is well-equipped to meet the demands of modern commercial and industrial spaces, solidifying its reputation as a trusted choice in the HVAC market. Whether for new installations or upgrades, the RTHD delivers reliability and performance that customers can depend on for years to come.
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