What is VRF in HVAC?

Having been available in the U.S. since the early 2000s, VRF offers superior energy efficiency and the ability to provide a quick return on investment. But what exactly does the VRF mean to HVAC contractors, builders and mechanical contractors, and how can you use it to grow your business?

Learn more about this state-of-the-art HVAC solution, facts about how it works, and how your customers and your contracting business can benefit from VRF systems.

VRF explained: What is VRF?

VRF stands for variable refrigerant flow, which goes a surprisingly long way toward describing how this system uses refrigerant for both air conditioning and heating. In a nutshell, VRF is a ductless, large-scale system for HVAC that performs at a high capacity.

Unlike split AC equipment, VRF allows multiple indoor units to run on the same system, which is designed differently depending on the application. VRF systems are considered either a heat pump system or a heat recovery system, which can heat and cool simultaneously.

VRF systems obtain their high efficiency through the use of inverter compressors. Inverter systems allow the compressor to ramp up or down based on the needs within each space. A non-inverter system ramps up the compressor at full capacity all the time. Essentially it’s either on or off. With inverter systems operating at lower speeds and capacity, the efficiency gains can be substantial.

This versatility means VRF products are customizable to meet the specifications of virtually any project, making them particularly appealing for commercial spaces and facility managers.

The VRF system diagram below shows refrigerant branch (RB) lines for cooling as well as single and group connections for individual and simultaneous cooling and heating.

What is the difference between VRF and VRV?

Both of these terms refer to the same technology. VRV is a trademarked term that stands for variable refrigerant volume. An air conditioning manufacturer sparked this innovation 40 years ago, and VRF refers to the general technology.

How does VRF work?

In a VRF system, the refrigerant passes through condenser units to indoor units, cutting down on the need for extensive ductwork and air handlers. The smaller pipes make it a bit easier to retrofit in older buildings than traditional HVAC systems.

As technology advances, previous limitations are disappearing. VRF systems can now be an ideal choice for commercial buildings and residential homes.

Removing ducts from the equation is part of the increased energy efficiency. The U.S. Department of Energy’s Energy Saver reports that more than 30% of energy consumption could be due to losses of cool air through ducts.

What are the types of VRF systems?

There are several types of these systems that contractors discuss: heat recovery or heat pump, two-pipe or three-pipe, and air-cooled or water-cooled.

A three-pipe VRF heat recovery system enables users to heat one zone while simultaneously cooling another. Three-pipe systems can be useful for facility managers of buildings with mixed-temperature needs who are striving to reduce energy consumption. Typical applications would include multifamily buildings, large office complexes and religious buildings with multiple classrooms, among others.

A VRF heat pump system typically uses two pipes and can also heat and cool but not at the same time. Two-pipe systems have their advantages, such as fewer pipes and connections to create opportunities for leaks. Less lifetime maintenance means more savings on the system over the long term.

Air-cooled VRF systems rely on outside air (even using ducts occasionally). Water-cooled VRF can be hidden away inside and, in some situations, can use geothermal systems already in place for increased efficiency.

What are the benefits of a VRF system?

If you’re weighing the advantages for a new building or home, a renovation or your current client base, here are a few examples of what you and your occupants will gain from VRF AC and heating over traditional HVAC.

• Energy efficiency: As mentioned above, leaky or unprotected ducts lead to a lot of wasted energy. Customers typically enjoy cost savings in utility bills and increased comfort after the initial installation.
• Customizable temperature settings: If the right VRF HVAC system for the building is selected, occupants can heat and cool different zones at the same time, allowing workers and sensitive equipment to stay safe.
• Sleek and compact: Compared to traditional equipment, VRF HVAC units are much less bulky, making them an excellent solution for retrofitting, renovating or outfitting areas with limited space.
• Scalability: Once thought to be mainly for commercial buildings, VRF systems have advanced to be compatible with a range of heating and cooling products. They can scale to control the climate in a small single-family home or a commercial high-rise.
• Quiet: VRF systems reduce ambient noise both inside the building as well as outside, particularly in comparison to traditional HVAC technology.
• Easy to install: Ducted HVAC equipment is notoriously heavy. While VRF should be installed only by trained and certified professionals, based on the type of VRF system, installation takes much less physical exertion.

But can all buildings benefit from VRF? As with most decisions contractors and builders need to make every day, the answer depends on your specific project. Factors include building size, space constraints, long-term cost savings vs. initial outlay and other considerations.

Is VRF better than split AC?

VRF systems can handle large spaces well, but are the energy savings worth the installation cost for residential homes? VRF can be worthwhile, particularly in two-story homes with varied heating and cooling needs. As technology continues to advance, setting up homes for the future can be a great selling point.

Residential homes can benefit from energy efficiency; it comes down to whether the initial outlay is worth it to your customers.