Trane CG-PRC007-EN manual SettingThe Unit, Isolation and Sound Emission, Servicing

Application Considerations

Certain application constraints should be considered when sizing, selecting and installingTrane air-cooled chillers. Unit and system reliability is often dependent upon proper and complete compliance with these considerations.Where the application varies from the guidelines presented, it should be reviewed with your localTrane sales engineer.

Note: The terms water and solution are used interchangeably in the following paragraphs.

UNIT SIZING

Unit capacities are listed in the “Performance Data” section. Intentionally oversizing a unit to assure adequate capacity is not recommended. Erratic system operation and excessive compressor cycling are often a direct result of an oversized chiller. In addition, an oversized unit is usually more expensive to purchase, install, and operate. If oversizing is desired, consider using two units.

UNIT PLACEMENT

1

SettingThe Unit

A base or foundation is not required if the selected unit location is level and strong enough to support the unit’s operating weight (see “Weights” section of this catalog).

For a detailed discussion of base and foundation construction, refer to the Trane Reciprocating Refrigeration Manual. Manuals are available through the localTrane office.

2

Isolation and Sound Emission

The most effective form of isolation is to locate the unit away from any sound sensitive area. Structurally transmitted sound can be reduced by using spring isolators. Spring isolators are generally effective in reducing vibratory noise generated by compressors, and therefore, are recommended for sound sensitive installations. An acoustical engineer should always be consulted on critical applications.

For maximum isolation effect, water lines and electrical conduit should also be isolated.Wall sleeves and rubber isolated piping hangers can be used to reduce the sound transmitted through water piping. To reduce the sound transmitted through electrical conduit, use flexible electrical conduit.

State and local codes on sound emissions should always be considered. Since the environment in which a sound source is located affects sound pressure, unit placement must be carefully evaluated. Sound pressure and sound power levels for chillers are available on request.

3

Servicing

Adequate clearance for evaporator and compressor servicing should be provided. Recommended minimum space envelopes for servicing are located in the dimensional data section and can serve as a guideline for providing adequate clearance.The minimum space envelopes also allow for control panel door swing and routing maintenance requirements. Local code requirements may take precedence.

4

Unit Location

a

General

Unobstructed flow of condenser air is essential to maintain chiller capacity and operating efficiency.When determining unit placement, careful consideration must be given to assure a sufficient flow of air across the condenser heat transfer surface.Two detrimental conditions are possible and must be avoided: warm air recirculation and coil starvation.

Warm air recirculation occurs when discharge air from the condenser fans is recycled back to the condenser coil inlet. Coil starvation occurs when free airflow to the condenser is restricted.

Condenser coils and fan discharge must be kept free of snow or other obstructions to permit adequate airflow for satisfactory unit operation.

Debris, trash, supplies, etc., should not be allowed to accumulate in the vicinity of the air-cooled chiller. Supply air movement may draw debris into the condenser coil, blocking spaces between coil fins and causing coil starvation.

Both warm air recirculation and coil starvation cause reductions in unit efficiency and capacity because of the higher head pressures associated with them. In addition, in more severe cases, nuisance unit shutdowns will result from excessive head pressures. Estimates of the degree of efficiency and capacity reduction in such situations can be determined. Consult your localTrane sales engineer.

Cross winds, those perpendicular to the condenser, tend to aid efficient operation in warmer ambient conditions, however, they tend to be detrimental to operation in lower ambients or when hot gas bypass is used due to the accompanying loss of adequate head pressure. As a result, it is advisable to protect air-cooled chillers from continuous direct winds exceeding 10 miles per hour in low ambient conditions.

Low Ambient Operation — 20-60Ton models — Human Interface Recommendations

When the temperature outside is subzero, who wants to be out there monitoring or troubleshooting diagnostics? Because we understand a service technician’s reluctance to do this, we recommend using a Remote Human Interface (RHI) panel. The service technician can troubleshoot and diagnose in the comfort of a mechanical room.

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