Mitsubishi Heavy Industries KXZ Heat Recovery VRF — Power, Precision, Performance

When your commercial project demands precise climate control, the Mitsubishi Heavy Industries KXZ Heat Recovery VRF series is a serious contender. Designed for large-scale applications, the KXZ range offers simultaneous heating and cooling, modular scalability, and design flexibility that suits everything from multi-storey offices to complex mixed-use developments.

This blog takes you through the entire KXZ commercial range, including every outdoor model, compatible indoor units, key specifications, installation planning advice, and local project examples. You will also find answers to common installation and commissioning questions that engineers and project managers often search for online.

Explore our commercial installation services:
https://www.climateworks.co.uk/commercial-air-conditioning

The Role of Heat Recovery VRF in Commercial Projects

Heat recovery VRF technology is ideal for buildings with varying heating and cooling demands in different areas at the same time. For example, an office facing direct sunlight may need cooling while an internal meeting room requires heating. The KXZ system captures waste heat from cooling zones and reuses it in heating zones, reducing energy consumption.

This capability makes the KXZ range suitable for:

• Multi-tenanted office buildings
• Hotels and hospitality complexes
• Retail and leisure developments
• Healthcare facilities
• Educational institutions
• Mixed-use developments with combined residential and commercial areas

KXZ Outdoor Unit Range

Mitsubishi Heavy Industries offers a wide range of outdoor units within the KXZ series to meet different capacity requirements.

Main outdoor models:

• KXZ20P – 20 HP
• KXZ30P – 30 HP
• KXZ40P – 40 HP
• KXZ50P – 50 HP
• KXZ60P – 60 HP
• KXZ80P – 80 HP
• KXZ100P – 100 HP
• KXZ120P – 120 HP
• KXZ150P – 150 HP
• KXZ200P – 200 HP

These can be combined in modular configurations to deliver systems exceeding 500 kW total capacity. Corrosion-resistant “C” models are available for coastal environments or exposed rooftops.

Compatible Indoor Unit Options

The KXZ system supports the full MHI commercial indoor unit range. This variety ensures you can match the right indoor unit to each space based on architecture, occupancy, and usage.

Options include:

• Four-way cassettes – ideal for open-plan offices or retail
• Slim ducted units – suited for areas with low ceiling voids
• High static ducted units – for long duct runs or large zones
• Ceiling suspended units – for rooms without false ceilings
• Floor-standing units – for perimeter heating and cooling
• Air handling unit (AHU) connection kits – for integration into existing ventilation systems

Technical Specifications and Capabilities

Key design features:

• Piping length – Up to 1,200 metres total
• Vertical rise – Up to 200 metres
• Distance to furthest indoor unit – Up to 300 metres
• Indoor unit count – Up to 128 per system (model dependent)
• ESEER performance – Up to approximately 8.5 under certain operating profiles
• Control – SUPERLINK II networking, BACnet, Modbus, and cloud connectivity

These generous allowances mean contractors can design systems for high-rise towers or horizontally spread facilities without sacrificing efficiency or reliability.

Installation Planning for the KXZ Series

Successful KXZ installation starts with early-stage planning. Consider the following:

Outdoor Unit Placement

• Maintain manufacturer-specified clearances for airflow and service access
• Use corrosion-protected models if placing units in coastal areas
• Plan for crane or hoist access on multi-storey buildings

Refrigerant Piping

• Follow MHI’s refrigerant pipe sizing tables to avoid pressure drops
• Ensure correct slope and oil traps for vertical risers
• Use only approved branch joints and headers to maintain warranty compliance

Electrical and Control

• Provide dedicated power supplies for each outdoor module
• Ensure correct earthing in accordance with BS 7671
• Plan control wiring routes for easy future expansion

Controls and Integration

The KXZ range can be controlled via:

• Individual wired controllers – simple operation for single zones
• Centralised controllers – schedule multiple zones and monitor performance
• BMS integration – using BACnet or Modbus gateways
• Remote monitoring – for off-site management and diagnostics

Advanced control enables precise scheduling and load sharing between heating and cooling demands.

Local Project Examples

Office Redevelopment in Basingstoke

A five-storey office building was retrofitted with a KXZ 120 HP system serving 65 indoor units. Heat recovery was used to redistribute excess heat from the south-facing façade to the shaded northern offices.

Guildford Hotel Expansion

A 40-room hotel wing was fitted with slim ducted units connected to a KXZ 60 HP module. Guests experienced quiet operation while the building benefited from lower running costs through heat recovery.

Reading Retail Complex

Multiple retail units with varied operating hours were served by a centralised KXZ system. Each tenant could control their own space without affecting others.

Why the KXZ Series Works for Complex Projects

• Simultaneous heating and cooling for maximum comfort
• Scalable modular design for phased installation
• Wide indoor unit choice for design flexibility
• Long pipe runs for challenging layouts
• Advanced controls for detailed zone management

Q&A: KXZ Installation and Selection

Q: Can I install KXZ in a phased project?
Yes. You can start with a base system and add modules later without replacing existing units.

Q: What is the maximum number of indoor units?
Up to 128 per system, depending on outdoor unit capacity.

Q: How long does commissioning take?
For a mid-size system, allow 2–3 days including pressure testing, vacuuming, refrigerant charging, and control setup.

Q: Is specialist training needed?
Yes. Installers should complete MHI’s VRF training to ensure correct setup and warranty validation.

Q: Can I integrate KXZ with an existing AHU?
Yes, using MHI’s AHU connection kits and control interface.

Steps for a Smooth KXZ Installation

• Carry out a full heat load calculation before selection
• Confirm available electrical supply and upgrade if needed
• Prepare site access for delivery and installation
• Coordinate with other trades to avoid conflicts in ceiling spaces
• Test and document all refrigerant pipework before charging
• Provide client training on controls and scheduling

Serving Hampshire, Berkshire, Surrey, and Oxfordshire

For commercial air conditioning projects in Hampshire (Basingstoke, Winchester, Southampton, Petersfield), Berkshire (Reading, Newbury, Wokingham), Surrey (Guildford, Woking, Camberley), and Oxfordshire, we have installed KXZ systems in offices, retail, and hospitality developments.

Learn more:
https://www.climateworks.co.uk/commercial-air-conditioning

References

1. Mitsubishi Heavy Industries – KXZ Product Catalogue
2. MHI Technical Installation Manual – KXZ Series
3. CIBSE Guide B2: Ventilation and Air Conditioning
4. IET Wiring Regulations (BS 7671)

Author Bio
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 efficiency, 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.

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