University Goes Green
If you think college students type term papers these days, you’re probably still listening to a Duran Duran cassette on your Walkman. Grab an iPod and step into Loyola University’s newest addition to its Chicago Lakeshore campus and you’ll see what we mean.
The university opened the $32 million Richard J. Klarchek Information Commons a year ago last month. The four-story, 70,000-plus square foot glass structure rests just 20 feet from Lake Michigan and essentially serves as a library – just not the kind you might be used to.
You won’t find books in this library but rather quick access to digital information. That’s a key service for today’s students who have to create electronic, media-rich content for their class work that might include a PowerPoint presentation as well as an embedded Flash program. These days, students also collaborate on assignments differently, sharing ideas electronically as easily as you may have traded your scribbled class notes back in the dark ages of, say, the 1980s.
So no books, but the Information Commons does feature more than 200 networked computer workstations, 50 laptops for loan and building-wide WiFi access all tied into the university’s extensive electronic library resources. (And in case you’re wondering as I was, yes, there is an old-fashioned library, the kind with books, connected right next door.)
The new facility is the first phase of the university’s plans to upgrade its academic research facilities. While the Information Commons represents the forefront of academic research, it’s the building itself that’s at the forefront of green mechanical building for our purposes.
Plans for the building were designed to cut energy use by half - and early indications are that the systems are performing a little better than that. As a result of energy reductions, cuts in water use and everything else that goes into constructing such a green structure, the university is hoping to eventually earn Silver LEED certification for the facility once all the approval processes are completed.
While students are downloading a document from halfway around the world, we doubt many will appreciate the mechanical work that will keep them comfortable year-round in this high-performance building that’s open 24/7.
How many students are likely to look up at the ceiling and realize hidden away are 15 miles of 5/8-inch PEX tubing that provides the wide-open study areas on two floors with radiant heating and cooling?
For this type of academic research, we paid a visit to Hill Mechanical Group, a Chicago-based PM Pipe Trades Giant started in 1936 that ranked No. 6 in our 2008 list of the country’s largest plumbing and piping mechanical contractors.
You can’t walk one step into the company’s suburban headquarters and not notice the sign that touts how the company is building a greener Chicago. And we barely got the introductions in order before James B. Hill III, vice president, handed us a thick sheath of color copies of past projects that reads like a Who’s Who of green building in Chicago.
“Our customers are very conscious about energy these days,” Hill explains. “Because of this, almost every one of our jobs starts out as LEED-certified or has a commitment to reduced energy consumption.” He doesn’t think the relatively recent growth of green building is new to how the company has grown over the years. He says his father, Warren Hill, currently the company’s chairman, would routinely try to save building owners money on energy and not just bring in a lower bid based on first cost.
“I don’t think anything has changed internally for us,” Hill says. “It's just that with so much emphasis in Chicagoland on ‘LEED’ and ‘building green,’ we now have recognized names to call the type of work the company has always tried to provide for its customers.”
Hill’s work for Loyola’s new building presented a number of challenges. As far as anyone can tell, the building features the country’s first use of a precast radiant ceiling system manufactured by a Wisconsin company called Advance Cast Inc.
“The building materials themselves are typical,” says Greg Ivaska, senior mechanical designer, “but putting it together - no one had experience with it before.”
Basically, the Hill crew had to prepare ceiling sections measuring 30 feet by 8 feet with about 300 feet of PEX laced around the rebar for each. In all, there were approximately 80 panels per floor.
In many ways, it helps to think of the building as being constructed upside down: The tubing may be buried in slab, after all, which doesn’t make it out of the ordinary. But since it forms the ceiling and not the floor, the Hill crew had to carefully account for other openings for the electrical and fire projection systems.
A grid of PEX tubing was tied to the rebar skeleton of each section before each piece was cast at the Wisconsin factory. Ultimately, what you see looking up at the ceiling of the finished building is nothing more than the painted surface of the concrete.
Meanwhile, ductwork for an air distribution system, which primarily serves the building’s standard ventilation requirements, runs under the raised floors.
A week after the office visit, we took a tour of the Information Commons, along with Wayne Silwa, project manager for the university, and David Lavan, engineer with Elara, Hillside, Ill., the consulting engineer for the building.
How It All WorksThe building really is a site to see. Picture a four-story glass box though which you can view Lake Michigan in the east straight through the building as you walk up to the west entrance. On the north and south sides of building are “bookends” constructed with material designed to mimic the style and limestone looks of the older Art Deco chapel and library on each flank.
Although the university wanted the building to be as transparent as possible, it also wanted it to be as energy-efficient as possible. With all that glass, that’s quite a challenge.
Before we go forward with our explanation of Hill’s mechanical work to heat and cool the space, we should point out that much of what follows only applies to the open study spaces on the first and second floors. Those bookends we mentioned house classrooms and offices, which are largely heated by traditional HVAC. A fourth floor, actually a partial floor with a vegetative roof taking up about half the space, doesn’t get the radiant treatment either. Finally, stairways are warmed with hydronic baseboard.
However, the open study areas are indeed quite open - 150 feet by 90 feet - and certainly highlight the primary advantage water will always have in transporting heat and coolness to such space.
In heating season, basically anytime the outdoor temperature drops below 55 degrees F, the radiant tubing embedded in the ceiling provides much of the heat needed for the study areas, although there are a couple of methods to maintain the indoor temperature:
- About 1,200 feet of hot water
finned tube lies just below the floor line along the east side of the study
- A system of air handlers also supplements the radiant ceiling and delivers warm air through ductwork and vents installed under the floors.
Not surprising to PM readers, the radiant slab works like a champ in the summer just as well as the winter. In this case, chilled water runs through the slab, keeping it at an average temperature of 63 degrees F or at three degrees above the relative indoor dew point.
A radiant slab is a radiant slab whether it’s above your head or below your feet. Just as occupants of a radiantly heated space are quite comfortable even when the surrounding air temperature is lower than a forced air system, occupants of the Information Commons are comfortable even at indoor air temperature approximately two degrees higher than they would be without the radiant effect. As a result, the air temperature can run around 77 degrees.
Obviously, if a building’s mechanical systems can be shut off, energy bills drop. Despite all the glass, the Information Commons is far from being the typically hermetically sealed building.
When the weather permits and temperatures range from 55 and 68 degrees F, the building’s automated system shuts off the air handlers and opens windows on the west and east sides, allowing fresh air to naturally ventilate and cool the study areas.
Motorized windows on the east side open directly to the outside, but it’s the west side that produces much of the natural ventilation to move the prevailing lake winds from east to west.
The west side features a double glass curtain wall, the first of its kind in Chicago, with windows that open into the interstitial space. Dampers below the ground level draw in outside air through the bottom of the space while motorized awning windows up top the three-story curtain naturally exhaust the warm air out like a chimney.
Of course, there’s a whole lot more to this than just opening some windows. With all this glass, blocking the sun’s rays is of great importance during cooling operations. The building’s automated system includes a weather station that even takes celestial readings of the sun. With that data, an outdoor light sensor triggers the precise angle of 4-inch blinds to deflect the afternoon sun. (The blinds, situated inside the cavity, can also be moved up and down, too.)
On the east side, simpler, but no less effective, roller shades diffuse the morning sun. Special coatings on the glass on both sides further keep solar gain in check throughout the day.
Keep in mind that this building is open around the clock, so much of the natural ventilation mode will take place at night. What’s more, the slab will naturally retain the nighttime’s “coolness” and help keep the space that much more comfortable even into the early hours of the morning without relying on the mechanical mode.
This combination of the mechanical and natural means the windows are open and the radiant ceiling is on.
This mode is only allowed when the outdoor dew point is 5 degrees F below the chilled ceiling temperature. Controlling the dew point is critical with this much radiant ceiling mass. The building’s design controls are based on the following:
- The dehumidification properties of the outside
air that ventilates the open study areas is improved through a three-coil
- A separate return air path on the open areas’ air handlers with
staged coils dehumidifies the space.
- Classrooms with conventional forced-air systems located nearby the study area further help out.
We gathered information for this story toward the tail end of last year, so the building still hasn’t weathered a full Chicago winter yet. However, the engineering company for the building supplied us with a couple of interesting realties from the height of a Chicago summer:
- In a two-week
period last August, the building was either in natural ventilation mode or
hybrid mode 37 percent of the time. The natural ventilation mode is so
effective that the indoor temperature could be maintained within approximately
one-half degree of the outdoor temperature.
- Based on two energy models done by Elara Engineering, the building is actually a bit more efficient than expected. Last August, the building energy bill for the month came to $7,333. That figure includes regulated loads for lighting and HVAC as well as power for the facility’s computers. And it’s actually 4 percent lower than what the engineering firm’s model calculations figured it might be.
Other Energy Efficient TechnologiesThe radiant heating and cooling systems, of course, aren’t all there is to making Loyola’s new Information Commons a candidate for LEED Silver status.
Here are some highlights of other materials and systems used in its green construction: