“Horizon II is a perfect example of a building that uses green building design and provides its tenants with a healthy place to live and work,” Mandyck added.

KEEPING OFFICES COOL IN TEXAS HEAT

Completed this summer (2002), the Horizon II building — 100,000 square feet rising four stories above suburban Austin — now serves as home to a major telecommunications company’s engineering and marketing offices. Expected to eventually become the workplace for up to 500 people — and with Austin’s average high temperatures for July and August in the upper-90s — Horizon II’s building designers took tenant comfort and HVAC system design very seriously, Tom Alexander, P.E., said.

Alexander, a principal of Talex Inc. Engineers, who planned the building with Austin’s Sixth River Architects, explained that while tenant comfort was first on the building owner’s list of requirements, energy efficiency, low lifecycle costs, and a progressive refrigerant were all factors considered in selecting the chiller for the building’s HVAC system.

“The building owners, The Kurt Simons Company, are ‘long-term’ owners who were looking to maximize tenant comfort, while reducing operating and maintenance costs,” Alexander explained. “Also, we were looking for a chiller using a refrigerant other than R-22, which we know is an ozone-depleting HCFC that you won’t be able to get after 2010.”

Chad Cullison, a sales engineer for Austin-based Carrier independent distributor Robert Madden Industries Ltd., first learned about Horizon II’s HVAC needs from Fox Construction, the project’s mechanical contractor. Fox was looking for two 200-ton chillers with aggressive energy efficiency and Cullison knew he had a perfect fit for Carrier’s 30GX Ecologic (Eta) air-cooled chiller.

“The ‘Ecologic Eta’ not only performs with an energy efficiency rating of 10.4, making it extremely energy efficient, it also uses R-134a environmentally-sound refrigerant, which won’t contribute to ozone depletion,” Cullison explained. “And with that type of efficiency, the Horizon II building will pay for the cost of its new chillers with energy savings in just two years.”

Talex Engineering’s Alexander agreed that the Ecologic’s efficiency was tough to beat. Alexander commented, “The redundancy of the chillers was very good and the Ecologic had a better lifecycle cost than any of the other design approaches that we looked at.”

To complete the job, Robert Madden Industries also provided four Carrier air handlers, variable air volume (VAV) boxes, and Carrier Comfort Network (CCN) controls. It all comes back down to tenant comfort, Ronnie Brooks, partner at The Kurt Simons Company, said.

“From a building management perspective, Carrier’s CCN controls allow us to be able to monitor and run diagnostics on all the Carrier HVAC equipment installed within Horizon II from one central location,” Brooks explained. “With maximum control over our HVAC equipment, we’re able to respond to our tenant’s comfort needs immediately.”

“We’re proud that we can provide our own customers with the comfort that they deserve. It’s icing on the cake to know that we’re maximizing their comfort while minimizing any harmful impact on the environment,” Brooks added.

THE GREEN BUILDING COUNCIL

More than 3,000 people attended the first annual U.S. Green Building Council (USGBC) Conference & International Exposition in Austin. A consensus-based coalition of leaders from across the building industry, the nonprofit USGBC (www.usgbc.org) works to promote buildings that are environmentally responsible, profitable, and healthy places in which to live and work.

In support of the USGBC’s efforts, and following the U.S. Environmental Protection Agency's guidelines for greening events and conferences, Carrier Corporation made a contribution to the nonprofit Leonardo Academy’s Cleaner and Greener Program toward emissions reductions to offset any air pollution caused by energy use associated with Carrier's participation in this event.

Publication date: 11/25/2002