Before the roundtable discussion began, the industry executives were led to the roof of The Ben to view the building’s variable refrigerant flow (VRF) condenser unit.
The Ben is one of approximately 100 hotels in the U.S. that use VRF technology from Mitsubishi Electric Trane HVAC US to heat and cool their properties.
“VRF technology was developed to provide heating and cooling, especially in a simultaneous situation, for small-zoned areas such as hotels, student housing, senior living facilities offices,” said Tom Varga, senior manager, business development, Mitsubishi Electric Trane HVAC US.
The technology has been around for years, but “the intent was never to develop HVAC for hotels or any other vertical market,” he said. “VRF technology was developed to create an efficient, sustainable technology to heat and cool, especially in those areas where utility rates are high. In Japan, for instance, the electricity rate is five times the typical rate in the U.S.”
The technology, which was introduced into the U.S. in October 2002, controls the flow of refrigerant through small fan coils placed in different zones. The system’s total capacity is distributed to each indoor unit via the branch circuit (BC) controller.
Varga said there are two types of VRF technology. “One is the heat pump, where all of the units are either cooling or heating. The other, which is used in hotels, can choose to cool or heat individual zones. VRF does that without all the infrastructure associated with the traditional system.”
He described how the system works. “The outdoor units are on the roof and then the pipe goes down to the BC controller—what I call the refrigerant traffic cop—which controls and directs the flow of refrigerant to multiple guestrooms on a single system, allowing it to provide heating and cooling at the same time. In the case of The Ben, like any 200-plus-room hotel, there’s multiple systems—I think 23 systems at The Ben—and that controls the guestrooms, public spaces, back-of-house operations, etc. When all the systems have been installed, the information from them can be seen on their front-end system energy management system, so you can truly control the property in a very efficient and effective manner from one location.”
He offered this advice to owners and developers considering VRF for a new hotel project: “Engage a company like Mitsubishi Electric soon into the early design or even the conceptual phase discussions. That way, we can work closely with the architectural and engineering teams to make an efficient decision, considering the mechanical limitations of the VRF product.”
He added that for an existing hotel, “VRF is a wonderful choice because you can install the system on a floor-by-floor basis, so you don’t have to close the hotel down in its entirety. You can do a phase-in approach if you don’t have the money to do the entire project at once. You may want to spread it over the course of 18 months or two years. At the end of the day, when all systems have been installed, you can tie them together and view them on an energy management system or property management system.”
For hotels, the HVAC system is one of the biggest contributors to operation costs. In fact, Varga offered a data point that found the HVAC system represents roughly one-third of the overall electric bill for the hotel property.
While he couldn’t qualify the cost savings produced by a VRF system, Varga told the story of a client in Indiana that owns several Embassy Suites properties that explains how VRF can be used to save money.
“The client told me he won’t build another Embassy Suites unless it has a VRF system because when he had only 12 guests during the pandemic at one of his properties that had a boiler and a chiller, he had to turn on the boiler and chiller in its entirety like it was a full hotel. Whereas, with the VRF, you can put everybody on one floor, have the system work for the zones on that floor, and the other floors can be put on setback.”
—Adam Perkowsky
