Editor’s note: This article first appeared in the July/August 2015 edition of Business Energy.
Screven Elementary School in Sylvania, GA, is a 143,000-square-foot facility built in 1989. When the facility was partially renovated in 2002, a dated and inefficient HVAC system remained.
When the pipes of the original water-source heat pump deteriorated, William Bland, superintendent of the Screven County School System, realized action was needed to repair the HVAC system. While the initial plan was to repair the old system, research showed that not only would the cost be substantial, but also there would be no increase in energy efficiency.Join us at the Leading Gathering of Distributed Generation and Microgrid Professionals at the 6th Annual HOMER International Microgrid Conference in San Diego, October 8-10th. Secure Your Spot Today!
As a result, the school elected to purchase and install a VRF zoning system from Mitsubishi Electric. “It was the energy efficiency that grabbed our attention,” says Mike Dixon, maintenance director at the elementary school. “We were also interested in the ability of the units to maintain the temperature within one or two degrees, and the quiet operation.”
Mitsubishi Electric recently unveiled its new line of Hyper-Heating Inverter (H2i) ductless and VRF zoning systems. “Mitsubishi Electric is the pioneer of ductless and VRF zoning technology in the US, and the first to develop low-ambient heating capabilities,” says Robert Byrd, a company spokesperson. “The H2i technology revolutionizes the heat pump by optimizing energy usage and delivering heat at very low outdoor ambient temperatures.”
The technology is ideal for various commercial applications, in that it helps facilities accommodate various load requirements for separate rooms or buildings, saving energy and maintaining valuable square footage.
According to Byrd, there are four major benefits of H2i technology:
- Energy savings– Because H2i technology recovers heat energy that would otherwise be wasted, energy usage is kept at a minimum. In addition, while traditional systems continually turn on and off to meet a desired temperature, the inverter-driven compressor quickly adjusts and maintains speed, reducing energy usage and increasing utility bill savings.
- High performance– A flash process cools the compressor, allowing the zoning system to heat rooms at lower outdoor temperatures without overheating. The process provides optimal heating performance at low temperatures. “In fact, systems can operate effectively, even in outside temperatures at minus 13 degrees Fahrenheit,” he says.
- Low life cycle costs– The highly efficient hyper-heating systems help decrease the overall equipment tonnage of projects. This means lower initial costs; the smaller outdoor system footprint and ability to be installed more quickly allows for reduced installation costs. The technology also eliminates the need for supplemental heat sources in many cases, such as fossil fuel burning or inefficient electric systems.
- Reduced maintenance costs- “Hyper-heating technology offers year-round efficiency for optimal occupant comfort, which translates to fewer complaints and system adjustments,” says Byrd.
Schools Choose VRF With Controls
Screven Elementary School was satisfied with Mitsubishi Electric’s service during the installation. The installation took less than 12 weeks and took place over the summer when school was not in session.
The VRF system allows Preston Dees, director of school safety and energy management for the Screven County School System, to monitor and control the cooling and heating in each classroom. “We have had an aggressive energy management system in place for five years, and we are documenting substantial savings with the system from previous years of record,” says Bland. In fact, average annual savings are $16,225, representing an average energy savings of 25%.
Mitsubishi offers an additional way to help HVAC systems manage energy, called the Diamond Controls Solutions. According to Byrd, one of the best ways to manage energy, particularly that used by HVAC systems, is with an automated controls solution, which can control numerous systems through a single interface.
Mitsubishi’s Diamond Controls Solutions pairs building automation controls with comprehensive customer service. Since HVAC is the largest significant feature that commercial controls systems manage, Mitsubishi’s new DC-600E Integration Controller system centers around the facility’s HVAC system. However, it can also manage the following: access control, air compressors, ancillary heating, boilers, chillers, centralized water plants, domestic hot water, energy recovery, generator monitoring, humidifiers, occupancy sensors, photovoltaic panels, pumping systems, refrigeration monitoring, sprinklers, thermostats, ventilation, and more.
The system also provides efficiency gains. VRF zoning systems consistently perform at 25 percent higher efficiency than traditional systems. Managing VRF through Diamond Controls Solutions provides an additional level of efficiency, because the systems come with built-in sensors, and the controls use the standard cooling and heating building controls best practices.
As a result of its efficiency, facilities can use Mitsubishi’s VRF and Diamond Controls Solutions in combination to help meet or even exceed US Green Building Council’s LEED requirements, as well as meet Energy Star requirements.
The technology also provides cost savings. The building’s facilities manager or engineer can use the controls to modify heating and cooling, as well as the other systems that are connected—all around the facility’s optimal schedule. The manager can also schedule setbacks based on weather forecasts. In addition, the system can check the ambient temperature conditions and adjust itself automatically, such as turning down the temperature during an unseasonably warm winter day.
Costs can also be reduced via utility rebates. For example, the Diamond Controls Solutions can adjust usage based on signals from a utility via a demand-response program.