Property owners searching for ways to make their buildings more energy-efficient should keep three letters in mind: VRF. They stand for Variant Refrigerant Flow, a type of heating and cooling system that has been the HVAC system of choice in Europe and Asia for decades but that has only recently gained popularity in the U.S.
What makes VRF systems so special is their ability to provide both heating and cooling simultaneously. Residents in one unit can crank up the heat while residents of another cool off. These systems hold the potential to reduce a building’s HVAC energy consumption by 30% to 40%. Since HVAC systems can account for 50% of a building’s energy costs, a new VRF system can mean significant utility savings.
“VRF systems have only been around in the U.S. for the past two decades, and many property owners still don’t fully understand their benefits or how they work,” Boland technical sales engineer Jack Wright said. “When installed properly, VRF systems can make a huge difference."
In his role at Boland, Wright contributes to a variety of projects including plan and spec jobs, direct equipment replacements, design-build jobs and complete package HVAC solutions.
Bisnow sat down with Wright to learn more about VRF systems, the properties they are suited for and how building owners can reduce their energy costs while giving tenants full control over the thermostat.
Bisnow: Let’s start with the basics: How do VRF systems work?
Wright: A conventional HVAC system mixes return air and outside air in an air handler or rooftop unit, which cools the air using water or refrigerant before sending it back to the space. With a VRF system, rather than sending all of the return air back to the central unit, you're sending the refrigerant directly throughout the building to cool or heat the air.
VRF systems determine the heating and cooling requirements for each zone, then refrigerant flow and direction is varied to match these requirements at the terminal units.
Bisnow: What makes VRF systems efficient?
Wright: VRF heat recovery systems can reduce a building’s energy consumption by sharing heat between different spaces. If you have a building where half of the residents want cool air and half want heat, a VRF system can recover the heat from a zone in cooling and redirect that heat to a zone that calls for heat, as opposed to rejecting all of the excess heat through the condensing unit, which runs [the] compressor harder and uses more energy.
Compressors are the main energy hogs in heating and cooling systems, so the less buildings need to run them, the better.
Bisnow: What kinds of buildings are particularly ideal for VRFs?
Wright: VRF is a great choice for many types of buildings, but it can work especially well with older buildings. Buildings constructed before the advent of central air often didn’t account for ductwork, which can make installing traditional systems difficult. VRF systems require smaller ductwork, as typically you are only ducting in the outside air to the terminal units. This means fewer renovations are required, and the system will make less of an impact on a building’s exterior appearance.
Geographically, VRF systems are a good choice for buildings in places like Washington, D.C., where temperatures in the spring and fall months are mild. These shoulder season months can lead to split calls for heating and cooling in a building, maximizing the energy efficiency of a VRF system.
Bisnow: Are there any drawbacks to using VRF systems?
Wright: While these systems can be more efficient than traditional HVAC solutions, they need to be designed and installed properly in order to reap those benefits.
VRF systems work best in properties where all the rooms are permanently set so you know how much cooling or heating a space will need. They are great for owner-occupied buildings, because the layout of these buildings typically does not change much over time.
In general, the design should try to incorporate spaces with varying calls for heating and cooling. For instance, designing a system with some zones facing the east and some facing the west will allow for heat recovery between these zones throughout the day as the sun warms different parts of the building.
Things can get trickier with commercial properties, since tenants may change regularly, and new tenants could purchase more floors and choose to knock down walls, create new conference rooms and expand. When this happens, VRF pipes need to be reinstalled throughout the new space.
The key thing to keep in mind is that VRF systems can be very efficient for most spaces, but only if they are selected and installed correctly. This is why building owners need to work with a company that specializes in these systems, like Boland, as opposed to others who may be less knowledgeable.
This feature was produced in collaboration between Bisnow Branded Content and Boland. Bisnow news staff was not involved in the production of this content.