Ask any member of the executive sales team at Mitsubishi Electric US, Inc. Cooling & Heating Division (Mitsubishi Electric) how the cooling and heating industry has changed over the last decade and they’ll have no shortage of words. They’ll tell you how technological innovations in HVAC (heating, ventilation, and air conditioning) have led to seismic shifts across the building industry, from dramatic energy and cost savings, to improved thermal control and increased occupant comfort.
At the cutting edge of this change, according to Mark Kuntz, senior vice president of sales, marketing, product strategy and engineering for Mitsubishi Electric, is the company’s Variable Refrigerant Flow (VRF) zoning technology, an energy-efficient, ductless cooling and heating system which Kuntz says is revolutionizing HVAC. Gone is the labyrinthine of duct work and cobwebbed boiler rooms. In their place, Kuntz says, is a system that is easier and more affordable to install and maintain, that comes with tighter more individualized control, and uses less energy.
Too good to believe? Perhaps. But use of VRF technology globally and in the United States is widespread and growing. Mitsubishi Electric alone, one of a dozen or so players in the market, has more than 15,000 systems active in the United States and Canada and has been recognized with awards ranging from the US Green Building Council’s 2014 Best of Building Award in the HVAC/Indoor Air Quality/Building Controls category to Plant Engineering magazine’s Product of the Year Silver Award for its Hyper-Heating INVERTER (H2i) CITY MULTI R2-Series VRF Zoning System. Their technology is seen in LEED-rated projects and retrofits across the nation, from single-family passive and net-zero homes, to schools, restaurants, residential skyscrapers, even the corporate offices of multi-state energy companies who pride themselves on efficiency.
“Right now, VRF technology has about 6% share of the cooling and heating market in the US, “ Kuntz says. “We see this continuing to grow into double digits in the next five years.”
Here’s a closer look at how the technology, invented in Japan, has affordably furnished the renovation of the one-hundred-year old David Whitney Building in Detroit, saved 25% in energy costs within two years of installation at Screven Elementary School in Sylvania, Georgia, and prompted industry competitors to rethink their product strategy.
Some Like it Hot. Others Don’t.
Mitsubishi Electric Cooling & Heating retrofit the David Whitney Building with more than 600 tons of Variable Refrigerant Flow (VRF) technology, while preserving the 19-story skyscraper’s historic character in Detroit’s hot new urban core
At the junction of Park Avenue, Woodward Avenue, and Washington Boulevard within Detroit’s resurgent Grand Circus Park Historic District, stands the renovated and nearly fully occupied David Whitney Building—a gem of a skyscraper in the Neo-Renaissance style, designed by the legendary architectural firm Daniel H. Burnham & Co. A century after its 1915 construction, the building’s restoration is a sign, like the arrival of corporate offices for companies like Twitter, Shinola, and Compuware, of the resurgence of Detroit’s urban core.
Named after the wealthy lumber and shipping baron David Whitney Jr., who made his fortune in white pine, the building, with its terra cotta and glazed brick façade, is regarded for its four-story skylit atrium adorned with ornately carved marble and gold leafing. It was once a premier address for some of the city’s best medical professionals, but, like many of Detroit’s historic skyscrapers, fell out of use as a result of disinvestment and the exodus of people from the city.
After sitting vacant for 15 years, the building, which overlooks Comerica Park (home of the Detroit Tigers) and was bought by the joint venture Whitney Partners LLC for $3.3 million dollars in 2011, is once again prime real estate. The $94.5 million renovation led by the Roxbury Group has resulted in 108 apartments, a boutique 136-room hotel called Aloft Detroit (part of Starwood Hotels & Resorts), a bar and lounge, and the Grand Cirque Brasserie restaurant expected to open later this year.
A major part of the renovation, led by local HVAC contractor RW Meade & Sons, was retrofitting the entire building with more than 600 tons of Variable Refrigerant Flow (VRF) technology from Mitsubishi Electric. Not tons of material weight, rather tons calculated by ice melt— the century-old mechanism for translating heat production into a measurable unit: the amount of ice that melts in one hour as a result of heat absorption. In modern construction, the conversion is a rough indication of a project’s size: about 400 square feet per ton, according to Will Scott, commercial sales manager at Mitsubishi Electric.
At 19 stories, the sheer size and mass of the David Whitney Building, not to mention its 22- to 28-inch-thick flooring, presented an immediate heating and cooling problem, says Vince Dattillo, vice president of construction and project management at the Roxbury Group. Forced air involving ductwork would have meant high installation costs and difficult work in crawl spaces.
According to Scott, Mitsubishi Electric’s CITY MULTI R2-Series Heat Recovery VRF system (the company’s energy-efficient, cooling and heating system), a modular design that lends itself to widespread line sets, eased installation by limiting welded connections and cutting labor costs and time. Led by foreman Andy Peters, a team from RW Meade & Sons unspooled 82 foot-long, pre-insulated lines of copper refrigerant piping, manufactured in Italy and locally distributed, from air-cooled outdoor units on the roof and in the basement. With few restrictions on the placement of tee and elbow joints, these lines were connected to branch circuit controllers on each floor, allowing for independent temperature control in as many as 16 indoor units per floor.
Scott is quick to point out that the system’s benefits go beyond ease of installation. The apartments in the building, nearly fully leased, cater to the increasing number of young professionals moving to Detroit’s urban core to work and live. Satisfying the comfort needs of this millennial set, as well as international hotel guests, required a precise system with versatility and individualized control.
“In a hotel and apartment, there are wildly different comfort demands. Of the two, hotels are more challenging. A visitor from the Middle East might want his room at 80 degrees, while someone from Canada wants hers at 68-69 degrees,” Scott says. “Whether guests are male or female, how much they weigh, personal preferences, these all come into play; individual comfort and control is of great value in a hotel.”
Producing adequate heat to keep occupants warm in a cold Detroit climate was a major challenge, Scott says, particularly in light of the project’s historic preservation guidelines requiring the single pane windows to be preserved. In each hotel room, temperature is controlled by modulating an electronic expansion valve within the indoor unit. Occupants in adjoining or nearby rooms can use heating or air conditioning as they wish without greatly compromising efficiency. Large open areas, such as the atrium; one- to two-bedroom apartments; and hotel rooms all operate in different thermal zones.