‘Green’ trend pushes engineers to be creative problem solvers

IOWA CITY - Sustainable design is in.

“Green” building was estimated to represent 44 percent of all commercial and institutional construction in 2012, and is expected to grow to 55 percent of all commercial and institutional construction by 2016, according to a recent report from McGraw-Hill Construction.

That's good news for engineers like Tim Fehr who enjoy the challenge that comes from that push to find ways to be more energy- and water-efficient.

“This is an exciting time to be in the field of building design, because the green building push continues to stretch our abilities as engineers to make our buildings more high-performing and more energy-efficient,” says Fehr, a mechanical engineer at Shive-Hattery, an architecture and engineering firm with offices in Cedar Rapids, Iowa City, and seven other locations in the Midwest. “When I started back in 1989, we weren't really looking at any of these things. Now, technologies are changing every year or two, and we're always working on coming up with ways to make renewable sources more viable and cost-effective.”

One local project that's a prime example of that “green” innovation is the education center at the Iowa City East Side Recycling Center, a 24,000-square-foot recycling complex that held its grand opening on Earth Day, April 22, 2012. The center is located at 2401 Scott Blvd. SE.

LEED (Leadership in Energy and Environmental Design) is an internationally-recognized program that provides standards for environmentally sustainable construction. Four certification levels are available for new construction - certified, silver, gold and platinum.

The education center has achieved LEED Platinum certification and will serve as a statewide case study in sustainable design.

It includes a main classroom, a kitchenette, restrooms, and storage and mechanical system spaces. It was designed by a team of about a dozen people, including architects, mechanical engineers, structural engineers, civil engineers, and electrical engineers, says Fehr, who was the mechanical engineer of record.

The architects focused on designing a space that met the needs of the building's owner (the city) and had an attractive interior and exterior while the engineers ensured the design was safe and functional. They made sure that everything was properly supported (structural engineer), designed the electrical systems (electrical engineer), were responsible for the plumbing and HVAC systems (mechanical engineer) and developed plans for the land around the building and bringing utilities into the building (civil engineer).

Getting all of these elements to work together to achieve high goals for energy efficiency and design is a challenge, Fehr says.

“There are any number of things that could throw off performance - a little bit too much glass on one wall, for example, could really impact the energy efficiency,” Fehr says. “It's a give-and-take.”

Successful give-and-take led to an attractive building that showcases environmental best practices like stormwater management, geothermal and renewable energy systems, and bringing in natural daylight while maintaining energy efficiency by using insulated, translucent, and spectrally-selective glazing.

The building's south-facing floor-to-ceiling windows, which allow viewing of the center's environmentally-sensitive site features, are outfitted with large solar-powered motorized sun shades that act as awnings when raised and block light and heat from the sun when lowered.

“The shades help us keep the building efficient. In the wintertime, you want sunlight streaming in to warm up the space. But in the summer, our cooling system would be working awfully hard and consuming a lot energy to counteract the sun beating in that south window, so we can lower the shades,” Fehr says. “This feature is an example of how the engineers and the architects worked together to make the building efficient while keeping a feature that was important to the owner - the views from these windows.”