What is the Difference between a Rooftop Unit (RTU) and a Split System?


Heating, Ventilation, and Air Conditioning (HVAC) systems are essential components in both residential and commercial buildings, ensuring comfort and air quality. Two common types of HVAC systems used widely are Rooftop Units (RTUs) and Split Systems. Understanding their differences can help property owners and facility managers make informed decisions regarding their HVAC needs.

What are Rooftop Units (RTUs)?

Rooftop HVAC systems, often referred to as RTUs, are self-contained units located on building rooftops. These units contain all necessary components for air conditioning and heating in one cabinet, including the compressor, condenser, evaporator, and often the heating elements. RTUs are common in commercial buildings due to their space-saving design and centralized maintenance advantages.

Key Features of Rooftop Units:

RTUs are designed for:

  • Space Efficiency: They free up indoor space that would otherwise be used for mechanical rooms.
  • Ease of Maintenance: Technicians can access RTUs easily on rooftops, reducing disruption to building occupants.
  • Scalability: RTUs can be modular, allowing for easy expansion or modification as building needs change.
  • Weather Resistance: Positioned on rooftops, RTUs are built to withstand outdoor elements.

What are Split Systems?

Split HVAC systems consist of two main components: an outdoor unit (condenser/compressor) and an indoor unit (evaporator/air handler). These components are connected by refrigerant lines, allowing for the transfer of heat between indoors and outdoors. Split systems are commonly found in residential buildings but are also used in smaller commercial settings.

Key Features of Split Systems:

Split HVAC systems offer:

  • Quiet Operation: Since the noisy components are outside, indoor units operate quietly.
  • Flexibility: They allow for zoning, meaning different areas of a building can be heated or cooled independently.
  • Aesthetic Appeal: Indoor units are compact and can be mounted high on walls or recessed into ceilings, maintaining interior aesthetics.
  • Energy Efficiency: Modern split systems often come with energy-saving features and variable-speed compressors.

Differences Between Rooftop Units and Split Systems

Installation and Placement:

  • RTUs: Installed on rooftops, they require crane access during installation and maintenance.
  • Split Systems: Components are typically installed separately; the outdoor unit can be placed close to the building or in an inconspicuous location.

Space Requirements:

  • RTUs: Save indoor space since all components are housed in a single unit on the roof.
  • Split Systems: Indoor units take up some interior space, though they are often compact and designed for minimal intrusion.


  • RTUs: Maintenance is conducted on the rooftop, reducing disruption to building occupants.
  • Split Systems: Indoor and outdoor units require separate maintenance checks, potentially causing more disruption if indoors.

Cost Considerations:

  • RTUs: Initial installation costs can be higher due to crane requirements and rooftop installation.
  • Split Systems: Generally more affordable upfront, especially for smaller buildings or residential applications.

Efficiency and Performance:

  • RTUs: Often chosen for larger commercial buildings due to their capacity and centralized design.
  • Split Systems: Provide flexibility and are suitable for smaller-scale applications where zoning and quiet operation are advantageous.

Choosing the Right HVAC System

Factors to Consider:

When deciding between RTUs and Split Systems, consider:

  • Building Size and Type: Larger commercial buildings often favor RTUs, while split systems are suitable for smaller commercial spaces and residential buildings.
  • Maintenance Access: RTUs offer easier access for maintenance but may require specialized equipment for installation.
  • Energy Efficiency Needs: Both systems can be efficient, but specific models and configurations vary in their energy-saving capabilities.

Consultation with HVAC Professionals:

To determine the best HVAC system for your needs, consult with HVAC professionals who can assess your building’s requirements, energy efficiency goals, and budget constraints. They can provide recommendations tailored to your specific situation.


Understanding the differences between Rooftop Units (RTUs) and Split Systems is crucial for anyone tasked with HVAC system selection for a building. Each system offers unique advantages depending on building size, maintenance preferences, and efficiency goals. By considering these factors and consulting with experts, property owners and facility managers can make informed decisions that ensure optimal comfort and cost-effectiveness for occupants.

While RTUs are ideal for large commercial buildings requiring centralized systems with minimal indoor space intrusion, split systems offer flexibility, quiet operation, and zoning capabilities suitable for smaller-scale applications and residential settings.

By weighing these factors against your specific needs and consulting with HVAC professionals, you can confidently choose the HVAC system that best meets your building’s requirements.

Need a Commercial HVAC Contractor in St. Louis Park, MN?

Locally owned and operated since 1991, Air Climate Control Inc specializes in commercial service and repair of air conditioning, heating, and refrigeration, serving Minneapolis and the surrounding areas with quality, prompt, and reliable work. Air Climate Control Inc strives to provide same-day service to ensure client comfort and satisfaction. We specialize in preventative maintenance plans as well as repair and can sub-contract for installation service. Our estimates are always FREE of charge. Call us TODAY for all of your commercial refrigeration, air conditioning, and heating needs!

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