Regardless of time of day, sun or shade, season of the year or special requirements, the systems provide personalized comfort to each room or space across multiple floors and areas by moving refrigerant to individual zones. For the end user, the result is precise temperature control and reliable cooling and heating.
That's good news for the students at colleges and universities nationwide who have high expectations for their dorms, classrooms, labs and recreational spaces. And that's good news for the school proprietors and facility managers who must meet these high student demands while also meeting a budget.
VRF systems, which can simultaneously cool some zones while heating others, have many features that help proprietors and facility managers, including energy efficiency, design and installation flexibility, lighter weight, lower life-cycle costs, quiet operation, and discreet indoor units.
This article looks at two applications of VRF in a college/ university setting. One project - a new, modern student housing facility in California - used VRF to meet strict energy codes and earn LEED Silver certification. The other project - the renovation of two historic dormitories in Ohio - paired VRF with geothermal technology, leading to a 61 percent decrease in energy consumption. In both cases, the schools selected an HVAC system that brought their campus' technology up to date and improved students' experiences - all while saving money.
For Suites on Paseo, a new student housing complex that serves six universities in San Diego, VRF helped the facility's developer and property manager meet not just local students' high expectations but also California's tough energy standards. Those energy standards are some of the most demanding in the nation. They dictate improved energy efficiency, enable demand reductions during peak periods and allow for future technologies to enter the market. The Suites on Paseo (Suites) followed these standards, resulting in LEEDR Silver certification and 287 very comfortable students. VRF played a large role in making that success possible.
Suites was developed by Village Lindo Paseo, LP (VLP). The Preiss Company (Preiss), Raleigh, North Carolina, operates the complex, managing its three adjoining buildings and 98,000 square feet of space. VLP wanted that space to be not just energy efficient, but energy efficient enough to merit LEED certification from the U.S. Green Building Council. To achieve this lofty goal, VLP called in TTG Engineers (TTG), Pasadena, California. Edgar Pagdanganan, mechanical department manager, TTG, guided the energy conservation effort. His recommendation: VRF. Pagdanganan said, "I was working in Singapore 14 years ago and I discovered this remarkable VRF technology that was popular in Asia long before it came to the U.S. There is no conventional HVAC system today that can touch the energy savings of VRF zoning systems."
California Center for Sustainable Energy (CCSE), San Diego, was called in to advise on a VRF-based HVAC design that would support the goal of LEED certification. Michael Bigelow, LEED certification specialist and owner of Bigelow Energy, LLC, Las Cruces, New Mexico, worked for CCSE at the time. Bigelow said, "I was thrilled to discover VRF engineering. The technology is impressive for its energy-conserving design. Instead of the fans running 24/7 like a conventional HVAC system, they run only when students call for cooling or heating."
Pagdanganan agreed that VRF was the right choice for the job, and was particularly impressed by the system's independent zone control, small footprint and reduced number of outdoor units. With the system specified, installation began and quickly finished. The startup was easy and "even the commissioning of the system went rather quickly," said Lee Rich, building maintenance supervisor, Preiss. Rich also referenced the simple maintenance since installation: "Every three months, I wash the filters. I like this system because it is user friendly and easy to maintain. Everything works well and I have had very few complaints from the students here."
The system's smooth operation is also due to the advanced controls network. Suites has 300 separate zones across its three buildings, all controllable from a central computer. Rich said, "From the computer in my office, my controls network allows me to override every single fan coil on this property. That's impressive." Rich said the controls network is ideal "not just for daily student comfort but for handling energy alerts," a component of meeting the state's energy codes. The new HVAC system receives alerts directly from the utility company and can be set to notify the manager or respond automatically, enabling a more effective and environmentally friendly use of energy. He added, "During such an energy alert, I like the fact that I have total control of the entire system."
For Suites, total control translates into significant energy savings. Bigelow worked with several simulations during the design process, comparing potential options to a baseline as part of LEED certification. Bigelow said, "Without the onsite generation from solar PV and fuel cells, our design was 32 percent more cost efficient than the baseline. When we look at just the cooling system, including the fans, the system provided a 40 percent annual kWh savings. This foundation allowed our all-in design to beat the baseline by 46 percent, which got us 11 out of 10 LEED points in the v2.2 system. Yes, there's a bonus point in there." Such energy savings and overachieving, a mark of VRF zoning technology, will make Suites a comfortable, healthy place for students to live for years and years to come.
Students across the country in Oxford, Ohio, have seen a similar improvement to their campus thanks to VRF. Likewise those behind the scenes - working to create an environment that aids in student learning without losing out financially - have benefited greatly. Miami University offered a renovation with goals similar to many other planned revocations - it had to improve efficiencies to reduce operational cost.
In 2010, their physical facilities department was tasked with developing a utility master plan to the year 2050. Because temperatures underground are relatively constant (around 55 degrees Fahrenheit), the school made geothermal heating and cooling a centerpiece of its sustainability strategies. The university is committed to ending on-campus coal burning by 2025.
"Geothermal is very advantageous for our climate in Ohio, where heating and cooling loads are closely matched over the year," said Doug Hammerle, PE, Miami's director of energy systems. "This helps balance the well field temperature and maximize the efficiency of the system."
The utility master plan included improving the efficiency of the two oldest buildings on campus - two residence halls from the 1800s with outdated HVAC systems. "Updating [these] HVAC systems was a dramatic showcase for demonstrating our commitment to sustainability," Hammerle said. To find the best technology to complement the geothermal, Hammerle turned to Brian Isaacs, director of corporate sales for Habegger Corporation, Cincinnati.
When Issacs learned of the project's sustainability goals and the unique needs for cooling and heating, he immediately thought of VRF. When a local VRF sales representative introduced him to the technology he "read their engineering manual and witnessed several VRF system installations around Cincinnati. I was soon convinced that modular water-source systems were the industry's most advanced engineering technology to partner with a geothermal campus."
Isaacs invited Hammerle and two local engineering firms to a nearby VRF training center for a demonstration. In this group was Alec R. Carnes, PE, CEM, LEED AP BD+C Senior Principal, Heapy Engineering, Dayton, Ohio. When Hammerle learned about VRF's simultaneous cooling and heating capability, he was sold.
He explained that 90 percent of the buildings on the 880- acre campus were heated by a central steam plant, and more than 50 major buildings were cooled by two central chiller plants. "A current limitation with our two-pipe fan coil system is they can do either heating or cooling but not both a / Umbra Stripe at the same time," Hammerle said. "This causes comfort control issues during mild weather. [VRF] solves this problem by being able to do both cooling and heating, irrespective of the temperature outside."
Hammerle was especially interested in the potential for energy savings that VRF offers - especially on the heating side. "It's impossible for a fossil fuel heating plant to hit a COP [coefficient of performance] of 1, whereas with combined geothermal and water-source heat pumps, it's possible to hit a COP of 10." To verify this, Hammerle asked Heapy Engineering for an extensive energy modeling analysis. Heapy's model showed a total building energy usage of 43 kBTU/h per square foot per year. Carnes recommended that Hammerle accept VRF for the two residence halls: "This option will enable Miami to maintain the historical and architectural integrity of these two legacy structures. Coupled with the geothermal wells, this will be far more efficient than a traditional system."
Seventeen 600-foot-deep geothermal wells were placed under the sidewalks surrounding the halls. As modern footings were unknown 150 years ago, the hand-dug basements had no space for the heat pumps. An easy-to-access mechanical room was built into the attic of each hall for the three heat pumps and centralized controller. To maintain the architectural integrity, custom cabinets were designed and built to house the indoor units for each room. "These cabinets are beautiful," Hammerle said. "None of this would have been possible without the two-pipe system design. The interior would have been severely cut up with a hydronic four-pipe system."
Before the two dormitories switched from coal-fired steam heat to geothermal heating and cooling, they showed an annual energy usage of 740,000 kBTU/h. Following the geothermal installation, this number dropped to 346,000 kBTU/h - a 61 percent decrease in energy consumption. The oldest buildings on campus had become the most energy-efficient. "This new system has already saved us a ton of money and enables me to have many more satisfied customers," Hammerle said. "The engineering has performed so well that I can say with certainty that VRF is my system of choice for all new outlying buildings on campus not tied into the central plant."
"Renovation of any historic building is a complex undertaking requiring a balance between the original architecture and modern building systems," Carnes said. "This was accomplished thanks to the installation flexibility of the VRF system." Carnes also praised the VRF engineering for allowing them to preserve their historic architecture while controlling energy efficiency.
The decision-makers at colleges and universities are increasingly turning to VRF, whether renovating an old facility or building a new one; whether working on dormitories, classrooms, offices, laboratories or recreational spaces; whether 'green' figures in the sense of sustainability or money. VRF's industry-leading efficiencies and whisper-quiet operation please both students and stakeholders; sometimes it's as simple as that.
is Mitsubishi Electric's senior manager, commercial marketing. In this role, he leads the marketing strategies, programs and initiatives for the division's commercial product line. Miskewicz is a certified LEEDR Green Associate and has several years of product marketing experience.