The first screw chiller with all the advantages of a quality centrifugal - and more.

High-end centrifugal chillers have a reputation for reliability, quiet operation, efficiency, and field-serviceability.

Fortunately, now there's a screw chiller with the same ideal balance of qualities: the 23XL Screw Chiller from carrier. A chiller that's also environmentally responsible and easy to install, with low life-cycle costs that make it your best value for medium-sized commercial applications.

Outstanding Energy Efficiency

The 23XL is engineered to exceptional full- and part-load efficiencies. Precise compressor tolerances in a design optimized for air conditioning duty lead to superior compression efficiency. And advanced, internally and externally enhanced heat transfer surfaces provide outstanding thermal performance.

A patented variable flow metering device eliminates inefficient vapor bypass and delivers precisely the right amount of refrigerant under all conditions. The result is superior part-load efficiency.

In addition, the integral FLASC (FLAsh SubCooler) increases the refrigeration effect and reduces compressor power consumption for a further reduction in operating costs.

Reliable, Long-Life Hermetic Motor

The 23XL uses the same simple motor cooling system proven effective for over 25 years in the Carrier 19D Series Hermetic Centrifugal Chiller.

The result is a cool-running hermetic motor which provides long life, while eliminating the shaft-seal leakage and machine room cooling requirements of open motors.

Quiet Operation For Application Flexibility

Some screw chillers have earned a reputation for being loud. But not the 23XL. It's inherently quiet design makes it ideal for acoustically demanding applications such as libraries, schools, and hospitals.

Built to Endure

The 23XL screw compressor utilizes AFBMA Class 5 bearings (the same kind typically found in jet engines) which provide precise rotor positioning. Carrier's unique design provides the most conservatively loaded bearing system in the industry. And a hydraulically activated capacity-control slide valve is located below the screw rotors to prevent the wear potential associated with top-mounted designs.

A host of other design features add up to make the 23XL a true "centrifugal-class" screw chiller. For example, double-grooved tube-sheet holes enhance joint structural integrity. A float-type oil sensor is used instead of lower-cost, less-reliable flow switches. O-ring seals on the hermetic compressor replace leak-prone gaskets. And straight-thread O-ring sealed fittings replace leaky, tapered pipe thread fittings.

Lower Installation Costs

For situations where access is tight, take-apart bolted construction disassembles and reassembles easily in the field. Individual components fit through a standard three-foot doorway. Add the optional unit-mounted starter and you'll eliminate start-up problems due to mis-wiring.

Other unique design features pay additional dividends during installation. The positive-pressure design keeps the footprint small for reduced floor-space requirements. The cool operating hermetic motor eliminates the hardware and labor costs of installing additional machine room cooling or ventilation equipment. And quieter operation reduces the need for expensive soundproofing - while allowing installation closer to occupied areas, for more flexible, cost-effective use of building space.

Ecological and Economically Sensible

The 23XL uses a proven, non-CFC refrigerant, HCFC-22 (HFC-134a is also available in selected models). Moreover, the 23XL's hermetic motor design eliminates the shaft-seal leakage of open-drive units, helping to keep these refrigerants inside your chiller and out of the environment.

At Last: a Field-Serviceable Screw Compressor

Typically, screw compressors cannot be field-serviced; they must be sent back to the factory for exchange - a costly and time-consuming procedure.

The 23XL, however, has a unique fully field-serviceable compressor, backed by the most comprehensive service organization in the industry. This can significantly reduce maintenance expense and downtime.

For routine maintenance, optional refrigerant isolation valves allow refrigerant storage in the chiller during servicing, eliminating expensive storage tanks and time-consuming transfer procedures.

Tested Repeatedly For Quality

Each screw compressor assembly undergoes a rigorous mechanical run-in test to check proper operation of components, and to verify that vibration levels and efficiencies meet strict specifications.

An ASME inspector witnesses a refrigerant-side proof test at 375 PSIG to verify that all heat exchangers meet ASME section VIII, Division 1 code for unfired pressure vessels. Then the entire chiller is leak tested at 300 PSIG with a refrigerant tracer gas. Next, the water side is hydrostatically tested at 1.5 times the rated working pressure. Meanwhile, vacuum testing ensures that there are no leaks into the chiller. After wiring, each chiller is also tested for proper controls operation prior to final shipment.

In addition, a regular program of audit testing is conducted in our performance laboratory under design conditions to verify predicted ratings.

Instant Command Over Powerful Capabilities

Sophisticated Product Integrated Controls (PIC) monitor over 100 functions, and display over 125 operating and diagnostic conditions. Yet the system is operator friendly and exceptionally easy to use. Guesswork is eliminated. Potential problems are quickly identified. And day-to-day monitoring and operations are greatly simplified.

If your chiller is connected to Carrier's Comfort Network (CCN), it's even simpler. All operating parameters for your entire HVAC system are intelligently monitored and controlled from one central location.

Perfect For Today And Tomorrow

Consider everything - efficiency, reliability, field-serviceability, ease of installation and operation, energy consumption, and total equipment and material costs - and the 23XL is clearly your best buy now… and your best investment in the future. To learn more about it, contact your nearest Carrier Representative. Or call 1-800-CARRIER.