Mini-Split HVAC

What Is a Mini-Split?

A mini-split HVAC system, also known as a ductless system, is a versatile heating and cooling solution ideal for commercial and mixed-use facilities that require comfort without the limitations of traditional ductwork. Instead of solely relying on ducts to distribute conditioned air, mini-splits use a network of outdoor and indoor units connected by refrigerant lines, allowing for various air delivery options based on custom needs of the building.

Like a traditional split system, a mini-split features an outdoor unit (typically a heat pump) paired with indoor air-handling units. For commercial environments, this flexibility allows precise temperature control in offices, retail spaces, classrooms, healthcare facilities, and more.

The indoor units are available in several varieties:

• Ceiling suspended units for discreet integration
• Wall-mounted units for flexible placement
• Horizontal ducted units for a clean appearance
• Multi-position ducted units similar to a traditional split system
• Floor-mounted units for supplemental heating and cooling

How Mini-Split HVAC Systems Work

Each indoor unit serves a specific zone, giving you granular control across different areas of your building. Instead of conditioning the entire facility with one system, each zone can be adjusted for occupancy, usage, or comfort requirements.

The outdoor unit houses the compressor and outdoor coil, while the indoor unit contains the blower fan and indoor coil. In cooling mode, the indoor unit’s refrigerant coil absorbs heat from the space and transfers it to the outdoor coil via refrigerant piping where the heat is rejected to the ambient air. In heating or “heat pump” mode, the opposite occurs – the outdoor unit pulls heat out of the cold ambient air and sends that warm refrigerant to the indoor unit where it heats the air to maintain a comfortable room temperature. Multiple indoor units connected to a single outdoor unit via refrigerant piping provides efficient and quiet operation.

This setup allows facilities to balance comfort, reduce wasted energy, and optimize performance by conditioning only the spaces in use.

Commercial Mini-Split HVAC Configurations

You can choose from single-zone or multi-zone configurations. Single-zone systems work best for server rooms, offices, or specialized areas that need independent control. In multi-zone systems, one outdoor unit supports multiple indoor units (2–8+), each with individual temperature settings. These are ideal for multi-tenant properties, educational buildings, or retrofit projects. In many situations, all the connected indoor systems must operate in the same mode (heating or cooling) at the same time . However, simultaneous heating and cooling operations are available in larger-scale VRF Heat Recovery systems.

Advantages of Mini-Splits for Commercial Applications

• Energy efficiency: High-efficiency mini-splits transfer heat instead of generating it, using up to 60% less energy compared to electric resistance heating.
• Retrofit-friendly: These are perfect for older buildings without existing ductwork.
• Occupant comfort: Quiet indoor units and individual zone control reduce complaints about noise and being too hot or too cold.
• Scalability: You can easily add units as your facility grows or tenant needs change.
• Incentives: Eligible systems may qualify for federal tax credits and local utility rebates.

Choosing the Right Size and Configuration

Proper sizing of a mini-split system is critical in a commercial setting. Factors like room usage, occupancy levels, ceiling height, insulation, and sun exposure must be considered. While BTU (British thermal units) sizing guides offer a starting point, a professional load calculation ensures your system delivers reliable performance and efficiency.

Mini-split HVAC systems should only be installed by licensed professionals trained in refrigerant and electrical work. A professional installation helps ensure proper system performance, warranty protection, code compliance, and long-term reliability.

Resources for Mini-Split HVAC Systems

• Buildings Big and Small Benefit from Electrification, Decarbonization with Updated Trane® Heat Pumps, Split and Rooftop Systems
• Webinar: Next-Generation Rooftop Units and Split Systems: Powered by Digitally Enabled Unit Controls
• Grow Room Split System Direct Expansion (DX) Units

If you think a mini-split HVAC system might work for your facility, contact your local Trane representative for an assessment and consultation.