If you manage M&E projects for large buildings, you already know that balancing heating and cooling demands across multiple zones can save thousands in energy costs. The Mitsubishi Electric City Multi R2 Series is designed specifically for that purpose, offering simultaneous heating and cooling from a single two-pipe system. This blog covers the full commercial range, complete with model specifications, installation guidance, and real-world troubleshooting insight for commissioning engineers.
Explore our commercial air conditioning installation services:
https://www.climateworks.co.uk/commercial-air-conditioning
How the R2 Series Works
The R2 Series is a heat recovery VRF system that transfers waste heat from cooling zones into heating zones using a BC Controller (Branch Controller). This design:
- Reduces energy waste
- Eliminates the need for separate heating systems in many applications
- Uses only two refrigerant pipes, simplifying installation compared to three-pipe systems
The system is suited to hotels, offices, hospitals, and mixed-use developments where different spaces require heating and cooling at the same time.
Model Range Overview
Mitsubishi Electric offers multiple capacities within the R2 Series. Notable outdoor unit models include:
- PURY-P200YLM-A1
- PURY-P250YLM-A1
- PURY-P300YLM-A1
- PURY-P350YLM-A1
- PURY-P400YLM-A1
Key Specifications
Capacities and figures are taken from Mitsubishi Electric’s UK technical catalogue:
- Cooling Capacity: 22.4 kW to 45.0 kW per module
- Heating Capacity: 25.0 kW to 50.0 kW per module
- EER: Up to 3.20
- COP: Up to 3.60
- Refrigerant: R410A
- Operating Range: Cooling -5°C to 43°C; Heating -20°C to 21°C
Multiple outdoor units can be combined to serve very large projects, up to 168 kW capacity in one system.
Indoor Unit Options
The R2 Series supports the full Mitsubishi Electric indoor product portfolio, giving design flexibility:
- Wall Mounted Units: Compact options for meeting rooms or small offices
- Ceiling Cassette Units: Four-way airflow for even distribution
- Ceiling Concealed Ducted Units: Medium to high static pressure for larger spaces
- Floor Standing Units: Ideal for areas without ceiling voids
Installation and Design Considerations
When designing and installing an R2 Series system, engineers should take note of:
- Pipe Length Limits: Up to 500 m total piping, with 90 m maximum height difference between indoor and outdoor units
- BC Controller Placement: Must be centrally located relative to connected indoor units
- Power Supply: Dedicated circuits with appropriate overcurrent protection are essential
- Refrigerant Charge Calculation: Particularly important for multi-unit systems to ensure proper oil return
- Control Options: Integrates with Mitsubishi Electric’s AG-150A touch screen controller or third-party BMS via gateways
Fault Codes and Commissioning Insights
During commissioning, some fault codes appear more often than others. Understanding these in advance can save significant time on site.
Common Fault Codes:
- P8: High discharge temperature
Likely cause: Insufficient refrigerant or poor airflow at indoor coil
Resolution: Check refrigerant charge, indoor filters, and coil condition - E6: Communication error between BC Controller and indoor units
Likely cause: Incorrect wiring or address setting
Resolution: Verify polarity, cable type, and dip switch settings - U4: Communication error between outdoor and BC Controller
Likely cause: Cable break or power supply issue
Resolution: Check continuity and confirm correct cable routing - L4: High pressure trip
Likely cause: Overcharged system, blocked condenser
Resolution: Inspect condenser fins, measure subcooling, adjust charge if needed
Case Study: Office Retrofit in Guildford
A commercial office building in Guildford underwent a full HVAC replacement in 2024. The contractor selected a PURY-P300YLM-A1 R2 Series system, pairing it with ducted indoor units for open-plan areas and wall-mounted units for small meeting rooms.
The heat recovery capability allowed heat rejected from the south-facing glazed façade offices to be used in the shaded northern areas, reducing boiler run hours by 40%. Commissioning involved fine-tuning fan speeds and confirming BC Controller sequencing to avoid unnecessary compressor cycling.
Why the R2 Series Fits Large-Scale Projects
Choose the R2 Series when:
- You require simultaneous heating and cooling
- Reducing plant space is a priority (two-pipe system)
- You need to integrate with a building management system
- Energy savings from heat recovery are a core requirement
Related Pages
References
[1] Mitsubishi Electric UK – City Multi R2 Series Technical Catalogue
[2] Mitsubishi Electric UK – R2 Series Installation Manual
[3] Mitsubishi Electric UK – Service and Fault Code Guide
Dr. Julian Carter
Dr. Julian Carter is a highly experienced thermal systems expert with over 15 years in the field, holding a PhD in thermal systems. His career spans academic research, consulting, and teaching, focusing on air conditioning and refrigeration systems. Dr. Carter bridges the gap between theoretical advancements and practical applications, providing expert insights to organisations like ClimateWorks, where his guidance informs decision-making and industry best practices. Notably, he has worked on international projects with organisations such as Daikin Industries, the International Institute of Refrigeration (IIR), and the United Nations Environment Programme (UNEP). These collaborations addressed energy performance, sustainable refrigerants, and advanced cooling technologies. Currently a lecturer at Edinburgh University, Dr. Carter combines his expertise with a passion for educating the next generation of engineers and advancing climate control technologies.
Get a fast no obligation quote today
.png){kind=small}
