Air Cooled Scroll Chiller 320-920 kW IDV Variable Capacity Plug and Play R410A Energy Saving Up to 40%
The Spec-Write Chiller for Commercial Projects
When engineering consultants specify mechanical systems for 500 kW commercial projects, the air-cooled scroll chiller is often the default choice due to its optimal balance of capacity, efficiency, and simplicity. IDV (Independent Double Variable) technology provides continuous capacity modulation from 12.5% to 100%, ensuring precise load matching to building requirements throughout daily operations.
For building designers, the scroll chiller offers predictable space requirements with factory-assembled packaging that includes all piping, wiring, and controls pre-installed. MEP engineers simply connect water lines and power, with compact installation options for rooftops, ground level, or structural platforms.
Key Features Deep Dive
IDV Variable Capacity: Continuous Modulation, Not Step Loading
The defining feature is IDV technology, where each scroll compressor independently varies capacity through digital valve control of scroll orbiting volume. Unlike traditional on/off loading with hot gas bypass, IDV provides smooth, stepless capacity control from minimum to maximum, eliminating part-load cycling energy waste.
Design Benefits:
- 12.5%-100% stepless modulation with no hot gas bypass waste
- Precise load matching maintaining supply water temperature within ±0.5°C of setpoint
- Reduced installed capacity requirements by eliminating oversizing penalties
- Lower starting current with soft start capability reducing electrical infrastructure
- IEER 4.7 for strong integrated efficiency in annual energy calculations
- Compatible with VFD on pumps and fans for full system optimization
Two Series for Different Capacity Ranges
Available in two series covering 320-920 kW range with design flexibility. RHAE/RCAE Series (319.9-860 kW) features dual independent refrigerant circuits for circuit redundancy. RHAG/RCAG Series (340-920 kW) offers optimized capacity points for maximum efficiency.
Design Benefits:
- 320-920 kW coverage filling gap between modular and screw platforms
- Dual independent circuits with separate compressor, refrigerant, and controls
- N+1 redundancy achievable with two chillers providing backup
- Heat pump or cooling-only models matching project heating requirements
- R410A refrigerant widely available and well-understood globally
- AHRI 550/590 certified performance to North American standards
Compact Single-Package Design
Complete factory-assembled unit includes compressors, shell-and-tube evaporator, microchannel condenser, fans, controls, and all interconnecting piping and wiring pre-installed and tested.
Design Benefits:
- Factory-tested as complete unit with no field refrigerant piping assembly
- Single lifting point for efficient placement
- Minimal site connections requiring only water pipes and power
- Reduced commissioning time with pre-tested systems
- Predictable lead times with standard models available from stock
- Lower installation risk through factory quality control
No Condenser Water System Required
Heat rejection occurs directly to ambient air through microchannel condenser and axial fans, eliminating need for cooling towers, condenser water pumps, piping, water treatment systems, and associated maintenance.
Design Benefits:
- No cooling tower eliminating rooftop water equipment and structural loads
- No water treatment removing chemical handling and disposal requirements
- No Legionella risk critical for healthcare, hospitality, and public buildings
- Reduced building services space with no condenser water plant room needed
- Lower total installed cost with fewer components to procure and maintain
- Simplified BMS scope with fewer systems to integrate and monitor
Energy Efficiency at Every Load Point
IEER 4.7 reflects chiller efficiency across full operating conditions. In typical commercial buildings operating at 50-70% capacity most of the year, IDV variable capacity maintains high efficiency where traditional chillers would cycle inefficiently.
Design Benefits:
- IEER 4.7 integrated efficiency reflecting real-world annual performance
- Up to 40% energy savings versus fixed-capacity alternatives at typical part loads
- Quick payback period with premium efficiency recovering investment in 2-3 years
- Compliant with green building standards contributing to LEED, BREEAM, Green Star
- Reduced carbon footprint through lower kWh per cooling ton
- Annual energy cost predictability enabling accurate lifecycle cost modeling
Flexible Installation Configurations
Self-contained design allows multiple installation configurations to suit architectural constraints including rooftop, ground level, intermediate structural platforms, or penthouse mechanical floors with proper ventilation.
Design Benefits:
- Rooftop installation with simple airflow management
- Ground level installation when rooftop structural capacity is limited
- Intermediate platform installation for high-rise buildings
- Coastal environment rating with corrosion-resistant microchannel condenser
- Multiple unit arrangements including side-by-side, parallel, or distributed
- Flexible pipe connection positions adapting to building riser locations
Technical Specifications
| Parameter |
RHAE/RCAE Series |
RHAG/RCAG Series |
| Cooling Capacity |
319.9-860 kW |
340-920 kW |
| Refrigerant |
R410A |
R410A |
| IDV Variable Capacity |
Standard |
Standard |
| IEER |
4.7 |
4.8 |
| Climate Class |
T3 – Full capacity at 55°C |
T3 – Full capacity at 55°C |
| Voltage |
380-415V/50Hz (other on request) |
380-415V/50Hz (other on request) |
| Certifications |
CE, Eurovent, AHRI 550/590 |
CE, AHRI 550/590 |
| BMS Protocols |
Modbus RTU, Modbus TCP/IP, BACnet IP |
Modbus RTU, Modbus TCP/IP, BACnet IP |
| Installation |
Rooftop/ground outdoor |
Rooftop/ground outdoor |
| Warranty |
5 years |
5 years |
Ideal Applications
Office buildings 5,000-50,000 m²
Retail centers and shopping malls
Hotels and resorts
Hospitals and clinics
Schools and universities
Government buildings
Data centers (small-medium)
Pharmaceutical facilities
Existing building replacements
Phased developments
Certifications & Standards
CE Certification
Eurovent Certification
AHRI 550/590
ISO 9001/14001/45001
