Variable Refrigerant Flow (VRF) Systems and Technology

Updated: August 2023
What is All-electric VRF Technology?

All-electric Variable Refrigerant Flow (VRF) technology is the fastest growing segment of the commercial HVAC industry. Across the United States, developers and owners are discovering how VRF heating and cooling systems help future-proof their buildings and reduce operational costs.

VRF technology divides a building into zones customized for comfort and energy efficiency. With no need for fossil fuels, an all-electric VRF system provides heating and cooling by cycling refrigerant between an outdoor unit and each zone’s ductless or ducted indoor unit(s). Up to 50 indoor units can connect to a single outdoor unit.

Zones have individual set points based on usage, occupancy, typical solar loads and user preferences. Facility managers can empower occupants to customize comfort in their zones while retaining the ability to optimize heating and cooling with centralized equipment control. VRF controls can integrate with building automation systems through standard communication protocols like BACnet®


A Variable-capacity Heat Pump System for Sustainable Heating and Cooling

Conventional systems emit byproducts including carbon dioxide (CO2), nitrogen dioxide (NO2) and particulate matter 2.5 (PM 2.5) when they generate heat by burning fossil fuels. As building codes and markets demand lower carbon footprints and greater sustainability, VRF systems offer a cleaner and more effective way to heat buildings.

Heat is everywhere. What we experience as heat is the natural movement of thermal energy between objects with different temperatures. Thermal energy moves from warmer objects to cooler objects. Instead of burning fossil fuels to generate heat, VRF systems use refrigerant to capture and repurpose existing heat from the environment. Air-source VRF systems draw heat from outdoor ambient air, while water-source VRF systems draw heat from a nearby water source such as a geothermal well. With our advanced Hyper-Heating INVERTER® (H2i®) technology, VRF systems can provide continuous heating at temperatures as low as -27.4° F.

In heating mode, the VRF outdoor unit expands the refrigerant gas until the gas is colder than the ambient air or water. The temperature difference enables the outdoor unit to extract thermal energy and transfer the heat to indoor units via refrigerant lines. Using this method, VRF technology provides more energy as heat than the system uses as electricity.

During cooling, indoor units absorb and transfer heat from interior zones to the outdoor units for rejection, leaving a cold indoor coil. A fan blows air across this coil into the space. The VRF system’s ability to provide both heating and cooling eliminates the need for separate air conditioners and heating systems.

Indoor units connected to a VRF heat-pump system operate in one mode at a time: heating or cooling. For buildings with diverse comfort needs, such as hotels or apartment buildings, building owners can choose a VRF heat-recovery system for simultaneous heating and cooling.


Quiet and Energy-efficient

VRF systems operate at ultra-quiet sound levels and use minimal energy to maintain each zone’s set point. The outdoor unit’s INVERTER-driven compressor varies fan speeds and the amount of refrigerant delivered to the indoor units, so the capacity and energy use match the real-time conditioning needs of the zones. As conditioning demands fluctuate with occupancy, activities and outdoor temperatures, the VRF system ramps up and down as needed to keep indoor temperatures steady. This method provides more precise comfort control, quieter operation and greater energy efficiency than conventional systems limited by noisy and energy-intensive on/off cycles. The continuous operation of VRF fans also helps distribute air, eliminate hot and cold spots and prevent the need to blow air at high velocities.


Compact and Modular for Cost Savings and Found Revenue

Lighter and more compact than conventional equipment, VRF systems can reduce upfront costs by requiring less structural support and fewer alterations to building facades. This smaller footprint combined with the diverse selection of ductless and ducted indoor units gives architects and engineers design flexibility to meet aesthetic and application requirements. Developers and building owners can also take advantage of the compact, ultra-quiet equipment to create revenue-generating amenities like rooftop lounges and cafes. Additionally, the modularity of VRF technology enables contractors to install systems floor-by-floor so developers can defer portions of the total installation cost until tenants sign leases.

As the leading provider of VRF systems, METUS has the expertise, support infrastructure and product portfolio to optimize heating and cooling in virtually any building, anywhere. Ready to begin? Contact a distributor or local representative today.


VRF Systems