Chiller Retrofit and System Modernisation

Yes. For equipment with usable mechanical components, the controller, sensors, relays, contactors and user display can be renewed. The new control strategy is prepared according to compressor count, circuit configuration and protection requirements. As the panel and software are prepared in the workshop beforehand, typical site downtime is 1–3 days.

They can be reused if their electrical specifications and measurement ranges are compatible with the new controls. Sensors are also replaced if their type, supply voltage or output signal differs.

No. The compressor motor must be suitable for variable-speed operation, and the manufacturer-approved frequency range must be known, generally 30–60 Hz for screw compressors and 35–70 Hz for reciprocating compressors. A drive is not installed without verifying lubrication, motor cooling, the operating envelope and oil return.

Changing from fixed speed to differential-pressure-controlled variable speed reduces pump consumption by 30–50% in systems where the pump operates at partial flow for extended periods. Actual savings are determined by measuring existing and new operating conditions; minimum evaporator flow is maintained in all cases.

Yes. A thermostatic valve can be replaced with an EEV using an appropriately sized valve, driver and sensors. Superheat is maintained at 3–5 K, with compressor consumption savings of 5–10%. Valve capacity is selected for minimum and maximum loads.

Not every retrofit increases capacity. Control and speed-management upgrades mainly improve part-load performance, monitoring and operating stability. If increased capacity is required, the compressor, heat exchangers, condenser and electrical infrastructure are assessed together.

Integration is possible through Modbus RTU/TCP, BACnet or dry contacts using a suitable controller and communication infrastructure. Data to be transferred and remote commands are defined before the project begins.

Because the use of R22 for servicing is prohibited, existing R22 equipment is generally converted to R407C or R422D. Conversion requires an oil change from mineral oil to POE and an expansion valve check; capacity decreases by 5–10%. Conversion costs are compared with investment in new equipment according to equipment age.

Typical alternatives to R404A and R507A are R448A and R449A. Capacity is largely maintained, but discharge temperature increases; some systems require liquid injection or discharge temperature limiting. The compressor manufacturer's approved refrigerant list is checked before conversion.

No. The compressor, oil, valves, seals, operating pressures and safety class must be compatible with the new refrigerant. A2L refrigerants are used only with manufacturer approval and an EN 378 assessment. Direct refrigerant conversion is not performed without calculating capacity and efficiency changes.

Energy consumption and maintenance costs before retrofit are established and compared with post-modernisation consumption, breakdown costs and expected service life. Energy savings claims are verified through measurements under comparable load and temperature conditions. Pump and fan speed-control projects have payback periods of 1–3 years at many facilities.