Trane ctv-prc007-en manual Selection Procedure, Part Load Performance, Roughing-inDimensions

Selection Procedure

Roughing-in Dimensions

The dimensional drawings illustrate overall measurements of the chiller. The recommended space envelope indicates clearances required to easily service the CenTraVac chiller. A view of the unit is superimposed on this drawing with unit support feet shown.

All catalog dimensional drawings are subject to change. Current submittal drawings should be referred to for detailed dimensional information. Contact the local Trane sales office for submittal and template information.

Evaporator and Condenser

Data Tables

Evaporator and condenser data is shown in the Performance Data section. Data includes minimum and maximum water flow limits and water connection sizes for all standard pass configurations and tube type. Pressure drops are calculated by the CenTraVac computer selection program.

Part Load Performance

The CenTraVac chiller possesses excellent performance characteristics over its full range of operation. The multi-stage direct drive compressor enables stable and efficient operation over a wide range of capacities, virtually eliminating the need for energy wasting hot gas bypass typically found on single stage chillers.

An in-depth examination of project- specific conditions and energy rate structures should be performed to appropriately evaluate total energy costs over a period of time. TRACE™, Trane’s unique energy analysis program, is particularly well suited for this type of analysis, as well as for economic evaluation of equipment and system alternatives.

Local utilities may offer substantial monetary rebates for centrifugal chillers with specific operating kW ratings. Contact your local utility representative or Trane sales office for further information.

The electrical rate structure is a key component of an economic evaluation. Most power bills are now constituted of 1/3 demand charge and 2/3 usage charge. The full load power consumption of the chiller plant is likely to set the kW peak and demand charge for the billing period. This places an increased emphasis on the need to keep the full load consumption of the chiller plant low.

There are a number of variables that should be considered in developing an accurate chiller load profile to use for measuring how one machine compares with another machine at part load. The use of outdoor air economizers, variations in chiller sequencing and chiller plant load optimization strategies should be considered. The use of a decoupled or primary/secondary water loop is generally acknowledged as the simplest, most efficient way to control multiple chiller water plants. This control strategy results in one chiller operating at a more fully loaded condition rather than multiple chillers operating at part load, which would require more pumping energy.

ARI Standard 550/590 provides chiller performance certification for the full load condition and the “NPLV” (non-standard part load value). The NPLV uses a generic weighted chiller load profile to simplify certification of part load performance data. Although these values are not necessarily a precise indicator of actual energy use, they do provide a valuable basis for comparison.

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