Every successful project starts with a framework. A vision statement. A blueprint. The editors of Engineered Systems are proud to present The Blueprint — a monthly Q&A interview with HVACR engineering’s leading voices. These one-on-one discussions will examine the trade’s history, current industry trends, the factors shaping the sector’s future, and more.

Mitsubishi Electric Trane HVAC US (METUS) is a provider of ductless and VRF systems in the United States and Latin America.

As a 50/50 joint venture between Trane Technologies and Mitsubishi Electric US Inc., the company provides innovative products, systems, and solutions capable of cooling and heating any application from a home to a large commercial building.

Tom Dowling, vice president of commercial business, METUS, introduces the industry to Hybrid VRF and discusses the codes and standards dictating its use as well as the market and its applications in the latest installment of the Blueprint.

Engineered Systems: Please take a moment and introduce yourself and METUS.

Dowling: I’m Tom Dowling, vice president, commercial business, at Mitsubishi Electric Trane HVAC US, also known as METUS. We are leaders in ductless and ducted mini-split and variable refrigerant flow (VRF) heat-pump and air conditioning systems for commercial and residential buildings. I’ve spent more than 25 years in the HVAC industry and joined METUS in 2015. I lead our team in product planning, controls solutions, and sales and marketing for the commercial business.

Engineered Systems: While VRF has become a popular option for designers worldwide and in the U.S., a new option has emerged – Hybrid VRF. What exactly is a Hybrid VRF system and how does it differ from a traditional VRF unit?

Dowling: A Hybrid VRF system is a two-pipe heat-recovery VRF system with a unique hybrid branch controller designed to use water as the heat transfer medium in occupied spaces. Soon available from METUS, Hybrid VRF systems only circulate refrigerant between the outdoor unit and the hybrid branch controller. The indoor units are connected to the hybrid branch controller via water pipes so the system can supply heating or cooling to the conditioned space where it is needed.

Our Hybrid VRF system modulates refrigerant flow, fan speeds, and water flow to match loads. This operation provides energy-efficient zoned comfort and simultaneous heating and cooling while requiring less refrigerant than other VRF systems.

Engineered Systems: Can you list a couple of benefits and advantages Hybrid VRF offers engineers?

Dowling: The use of water piping indoors simplifies the installation, providing more flexibility and lower costs than copper refrigerant piping. Fewer brazed connections reduce the potential for leaks. In some jurisdictions, refrigerant concentration in smaller spaces is an issue. With Hybrid VRF, that concern is removed because the indoor unit in the occupied space has no refrigerant.

Engineered Systems: What about customers – what options best benefit customers?

Dowling: Hybrid VRF systems provide customers with stable air temperature control and improved comfort cooling. Also, while VRF indoor units are already whisper-quiet, indoor units with water fan coils can be even quieter.

Limiting the refrigerant layout to the outdoor unit and hybrid branch controller simplifies maintenance and future retrofits. Plastic water pipes are less expensive to install and easier to isolate and replace during retrofits and repairs.

Engineered Systems:  What vertical markets/applications are Hybrid VRF best suited for?

Dowling: We expect Hybrid VRF systems to have applications in commercial settings, such as multifamily and modular buildings, hotels and lodges, K-12 and higher-education venues, senior living facilities, high-rises, indoor agriculture applications, and shopping centers.

Engineered Systems: Is there a market for Hybrid VRF or is this too much of a niche technology to really take off in 2021-2022? Are there codes/standards already in place guiding the future of these units?

Dowling: Hybrid VRF systems are popular in parts of Asia and Europe but are brand new for METUS in the U.S. market. It was always our intention to introduce this technology to the U.S. market, but evolving commercial building regulations and refrigerant codes make this product launch timely. The next-generation technology in Hybrid VRF systems delivers energy-efficient zoned comfort while solving ASHRAE 15 design challenges.

Engineered Systems: Is there anything else we should know, or any parting advice you’d like to provide?

Dowling: At METUS, we’ve been at the forefront of sustainable innovations. We’re constantly striving to develop products supportive of our customers’ comfort today and our shared wellness in the future.

The market opportunity for Hybrid VRF looks bright. Several markets worldwide are taking note of the changing climate and looking to implement solutions and regulations to reduce carbon footprints. Hybrid VRF systems extend the benefits of all-electric VRF technology to new designs for a more sustainable built environment. With Hybrid VRF technology, building owners can promote occupant comfort and wellness while future-proofing their facilities as codes and regulations change.

Engineered Systems: If readers are interested in connecting with yourself or METUS, where should they turn?

Dowling: We recently redesigned our website, MitsubishiComfort.com with dedicated content for both homeowner and professional audiences. It’s a great place to start.