PWMC / RWC Water-Cooled Chiller
Modular water-cooled chiller from 10 to 70 TR per module with up to 16 modules combinable, offering incremental capacity expansion, N+1 redundancy, and optional heat-pump operation — suited to phased or mission-critical cooling builds.
The PWMC/RWC is Petra Engineering's water-cooled modular chiller, built around individually factory-charged modules of 35–246 kW (10–70 TR) each. Up to 16 modules can be combined on a common hydraulic header, giving a practical combined capacity ceiling well above 3,900 kW without the single point of failure inherent in a large monolithic chiller. Each module operates as a standalone refrigeration circuit with dual scroll compressors, a stainless steel brazed-plate heat exchanger as the evaporator, and a water-cooled condenser — all within a heavy-gauge galvanised steel chassis rated to 5,000 hours of salt-spray exposure.
The modular architecture addresses three distinct procurement scenarios. First, phased construction: a developer can commission a single module at handover and bolt on capacity as occupancy grows, deferring capital expenditure rather than sizing for peak load on day one. Second, N+1 or N+2 redundancy without a full standby chiller: data centres, hospital critical zones, and process-cooling applications can specify one additional module as the standby, keeping any single module offline for maintenance without load shedding. Third, retrofit: modules can be installed through standard door openings and assembled in plant rooms that cannot accept large monolithic equipment.
Heat-pump mode is an available option, delivering hot water up to 54 °C — useful in GCC district-energy schemes where a single refrigeration system serves both chilled-water and domestic-hot-water loads, reducing overall plant count. BMS integration via BACnet, Modbus, or LonWorks is available as an option, enabling individual module-level monitoring and staged start sequencing within a building automation framework. Water isolation valves per module allow live maintenance without plant-wide shutdown.
Technical specifications.
| Cooling capacity per module | 35–246 kW (10–70 TR) |
| Maximum modules combinable | 16 |
| Refrigerant | R-410A (factory charged per module) |
| Compressor type | Dual scroll per module, independent circuits |
| Evaporator type | Stainless steel brazed-plate heat exchanger |
| Salt-spray corrosion rating | 5,000 hours |
| Heat-pump hot water output (optional) | Up to 54 °C |
| BMS protocols (optional) | BACnet, Modbus, LonWorks |
| Casing | Heavy-gauge galvanised steel, electrostatic powder coat |
Use cases.
- ›Phased commercial or mixed-use developments where cooling capacity is added incrementally as occupancy grows, deferring capital expenditure
- ›Mission-critical facilities (data centres, hospital plant rooms, process-cooling) requiring N+1 or N+2 redundancy without a dedicated standby chiller
- ›Retrofit plant rooms with access constraints where modular units can be delivered in sections and assembled on-site
- ›GCC district-energy schemes specifying heat-pump mode to serve both chilled-water and domestic-hot-water loads from a single refrigeration plant
- ›BMS-integrated buildings requiring module-level monitoring and staged sequencing via BACnet, Modbus, or LonWorks