When a traditional four-pipe system was deemed not economical enough, a hybrid of Daikin equipment became the basis of design.

NSU found its solution in a system comprised of two 79-ton Daikin RoofPak® units, one 15-ton Daikin Maverick® II packaged rooftop system, two 10-ton model DC Daikin rooftop systems, and four Daikin variable refrigerant volume (VRV) systems.

“We have a good relationship with the consulting engineer,” said Chad Smith, vice president, Airetech Corp., Tulsa, Oklahoma. “We considered packaged systems with variable air volume (VAV) boxes and hydronic systems with fan coils before arriving at the hybrid solution.”

The main event space is served by the two ground-mounted RoofPak units. The dual RoofPaks condition the arena by modulating the outside air to meet the ventilation requirements of the occupancy level during events.

Other areas, such as the athletic offices, locker rooms, and meeting spaces, required individual zone control.

“To maintain temperatures in the smaller back-of-house spaces, we used Daikin VRV equipment to provide a distributed system with individual zone control,” said Duane Harman, the project’s consulting engineer. “We chose the VRV systems as a multi-zone air conditioning system to satisfy the need for thermostatic control throughout these spaces and to help save energy.”

A 15-ton ground-mounted Maverick system serves the locker rooms. Both the RoofPak units and Maverick system were customized with energy recovery wheels.

“We designated energy recovery ventilators [ERVs] on the rooftop units that serve the arena and locker rooms to further reduce the overall compressor loads on the building and to conserve energy,” Harman said.

The four VRV systems incorporate fan coil units to serve the remaining building spaces. A second construction phase added 3,000 square feet of meeting space, supplemented by two roof-mounted, 10-ton packaged Daikin rooftop units with constant air volume.

This mix of hybrid Daikin equipment at the NSU center allows the university to minimize ongoing operating costs with energy-saving equipment while providing flexibility for occupant comfort based on usage of each space.

CHILLED BEAMS A SMART CHOICE FOR CANADIAN SCHOOL

Amber Trails Community School in Winnipeg, Manitoba, Canada, was designed to challenge the existing standards for school design and create exciting new visions for education. An abundance of fresh air, sustainable design elements, and natural light are incorporated to teach students about sustainability and help them study by providing a healthy learning environment. On top of housing K-8 students, the 78,000-square-foot facility also serves as a daycare facility and public library.

To match its sustainable design, the building uses chilled beam products as its primary source of air distribution. The beams feature the aerodynamic properties of Titus’ ceiling diffusers and benefit from the use of hydronic coils and induced air, reducing energy consumption associated with removing sensible thermal loads.

In this application, the primary air is discharged through nozzles located along the beam and supplied to the beam’s mixing chamber. The nozzles inject this air into the mixing chamber at velocities capable of inducing room air through one or two coils where it mixes with the primary supply air. This air mixture is then discharged through the ceiling slot diffusers into the space, providing high cooling outputs with low amounts of primary air. The reduced volume of air allows for smaller (and less expensive) air handlers and ducts in addition to reduced energy consumption.

The supplied air from the air handling unit is tempered and dehumidified to handle the latent load. The remaining loads in the space are addressed via the chilled beam’s heat exchanger. Applications with low latent cooling loads could potentially use 100 percent outdoor air, allowing for a dedicated outdoor air system (DOAS) with energy recovery that would further reduce total system energy consumption.

The chilled beams in this project can be used for both heating and cooling and are offered in 12- and 24-inch widths and 2- to 10-foot lengths. They can be easily integrated into different grid styles within a suspended ceiling or even in drywall ceilings. The low overall height of these chilled beams make them well-suited for reducing space required for false ceilings.

Most conventional HVAC systems depend on the delivery of large volumes of air to condition the classroom. According to Titus, chilled beam systems typically reduce ducted air requirements by as much as 60 percent by relying on their integral heat transfer coils to offset most of a space’s sensible cooling and heating requirements. Chilled beams allow classroom ducted airflow rates to be reduced to that which is required for space ventilation and latent cooling and provide a constant volume of ventilation air to the classroom at all times.

Amber Trails Community School, which has earned Leadership in Energy and Environmental Design (LEED) Platinum certification, has a total occupancy of 775 students and staff. Thanks to its sustainable design and energy-efficient HVAC system, the multipurpose space serves as a daily reminder to students, teachers, and the general public about how buildings can have a positive impact on communities.

DEVELOPMENT BUILT AROUND DISTRICT GEOTHERMAL 

Global developer Taurus Investment Holdings has officially opened its $2 billion sustainable community, Whisper Valley, in East Austin, Texas — a community the Geothermal Exchange Organization (GEO) calls a commercial-scale development of residential homes. The company’s vision is to attract buyers who want to lead a socially responsible lifestyle with affordable and energy-efficient homes in a sustainable development.

“We came to Austin because there is already an appetite for sustainable living, and we’ve had a terrific response,” said Douglas Gilliland, president of Taurus of Texas. “What makes us different from other eco-developments is the size and scale of Whisper Valley and the ability to offer high-tech, sustainable homes that utilize renewable energy sources without sacrificing affordability.”

Homes in Whisper Valley start from the low $200,000s to $400,000s. The 2,062-acre mixed-use development consists of more than 700 acres of open space, residential neighborhoods, planned retail, consumer services, restaurants, and commercial sales.

Every dwelling at Whisper Valley is an Eco-Smart Certified Home and includes a geothermal heating and cooling system.

Each home in the first phase of the development has a Bosch geothermal heat pump and a geothermal heat exchanger in a single vertical borehole near the lot boundary. The individual boreholes are connected to a larger geothermal loop field that maximizes efficiency.

In addition to the Whisper Valley geothermal systems, solar panels will generate electricity to achieve zero-energy capable homes, which are designed and built to meet Austin’s forward-looking carbon-neutral standard for new residential construction.

“The key to making [our] model work is that we dealt with the upfront cost of providing the geothermal heat pump and the solar by creating a unique financing program where the consumer can pay for that investment in the home through savings in their energy costs,” says Gilliland.

“Geothermal heating and cooling equipment is one of the most efficient today, based on information from the U.S. Environmental Protection Agency [EPA],” said Phil Schoen, Geo-Enterprises’ president, whose company is handling geothermal drilling and pipe laying for the development.

The boreholes for phase one, which includes 237 lots, have been connected to the district piping system, explained Axel Lerche, Eco-Smart partner.

“Through the district piping system, we create significant savings on everybody’s utility bills,” Lerche said. “Our homeowners are paying Eco-Smart a small fee per month on a 25-year term. And this monthly payment should be lower than the savings on the homeowners’ utility bills, so it’s a win-win situation.”  

SUSTAINABILITY BRIEFS

• Two ASHRAE certification programs, the Building Commissioning Professional (BCxP) and Building Energy Assessment Professional (BEAP), have been recognized by the U.S. Department of Energy (DOE) as meeting the Better Buildings Workforce Guidelines (BBWG). The ASHRAE BCxP certification is for individuals who lead, plan, coordinate, and manage a commissioning team to implement commissioning processes in new and existing buildings. The ASHRAE BEAP certification is for individuals who assess building systems and site conditions, analyze and evaluate equipment and energy usage, and recommend strategies to optimize building resource utilization.

• The Building Technologies Office (BTO) of the DOE is investing up to $15.8 million in 13 projects designed to drive innovation in early-stage research and development of advanced building technologies and systems. The innovations will serve as foundations for future technological developments and reductions in building energy consumption. The BTO says the Building Energy Efficiency Frontiers & Innovation Technologies (BENEFIT) Awards span the building technology innovation spectrum, from novel materials exploration to more accurate sensors; exploration of electric- and fuel-driven hybrid vapor compression technologies; and advanced control algorithms, modeling, and analytics for reducing the power consumption of miscellaneous electric loads.

• Sunflare Inc.’ssays its Capture4 solar technology represents the first high-quality, mass production of flexible, light, thin, and affordable solar cells. Each SUN2 cell is composed of stainless steel layered with copper, indium, gallium, and selenide (CIGS) semiconductor materials only a few micrometers thick. Sunflare panels can be secured to any surface with a special double-sided tape and do not require aluminum framing, glass, or mounting hardware.

• Carrier Corp. has released the latest update of its HVAC system design and energy modeling software. Hourly Analysis Program (HAP) v5.10, is designed to serve HVAC engineering professionals involved in the design and analysis of commercial building systems. According to Carrier, the HAP software update provides new features for Leadership in Energy and Environmental Design (LEED) analysis, supports compliance work for current ASHRAE standards, enhances modeling capabilities, and delivers productivity enhancements.

• HVAC Load Reduction® (HLR®) technology from enVerid Systems Inc. is designed to reduce indoor air contaminants, such as carbon dioxide, aldehydes, and volatile organic compounds (VOCs), as well as energy usage. According to enVerid Systems, instead of the traditional process of replacing the entire volume of a building’s indoor air every one to two hours, HLR modules clean and recycle existing indoor air. This enables a 60-80 percent reduction in required outside air intake, and a decrease in cooling and heating energy consumption of 20-30 percent (up to 40 percent in peak periods).

Publication date: 11/13/2017

Want more HVAC industry news and information? Join The NEWS on Facebook, Twitter, and LinkedIn today!