Students living in Carleton College’s newest dormitories need not tiptoe over chilly floors between empty pizza boxes, dirty clothes and dozing friends — they will step comfortably around these obstacles thanks to an in-floor radiant heating system.

Radiant heating and other sustainable construction technologies are a primary feature in two new dormitories, Cassat Hall and Memorial Hall, the construction of which is underway at the small, private liberal arts college, based in Northfield, Minn., about an hour south of the Twin Cities.

Recently named one of the 25 “greenest” colleges in the United States, Carleton College has been aggressive in supporting campus sustainability initiatives. The most visible project is its 1.65-megawatt wind turbine, which defrays nearly 30 percent of campus energy needs and represents the first utility-grade installation by a college or university.

Going For Gold: When administrators began planning additional student housing, they turned to the U.S. Green Building Council and its Leadership in Energy and Environmental Design (LEED) program to guide the project’s sustainable design goals. The twin residence halls, which will house approximately 230 students, are expected to meet the Gold-level requirements for LEED certification, the nationally accepted benchmark for the design, construction and operation of high-performance green buildings.

Planners selected radiant floor heating for its contribution to cost-saving energy efficiency in delivering consistent and even temperatures to residents. “Because radiant heating warms people and objects directly (as opposed to heating air), students will be more comfortable, while the building will be more energy-efficient,” explains Jim Carver, project manager for the installing contractor — Egan Co., based in Brooklyn Park, Minn., with a branch office (Nietz Mechanical) in Rochester.

“Since spaces feel warmer with radiant, the system will enable the college to deliver greater occupancy comfort at lower thermostat settings.”

Carver adds that because the distribution of heat will be more consistent throughout the buildings, there will be less need to “over-heat” some zones with supplemental systems — such as baseboard heat — in order to compensate for areas that seem too cool. In fact, the radiant heating system designed by Uponor is expected to reduce the project’s heating costs by nearly 12 percent, or roughly 8.5 cents per square foot, according to the project’s design engineer, Peter A. Potvin, P.E., LEED AP, a principal at the St. Paul, Minn.-based LKPB Engineers.

Attractiveness Of Radiant

These twin dorms include underfloor radiant heating and solar domestic water heating.

“Radiant heating was attractive for this project because it yields higher and more uniform comfort levels than conventional systems and is cost-effective, energy-efficient and requires low maintenance,” says Potvin. “Capitalizing on the large mass of concrete, the system will absorb, store and re-radiate heat right at floor level, making residents feel more comfortable, with no drafts and no noise.”

Moreover, while radiant systems tend to yield consistent temperatures within a room, spaces heated with traditional forced air can vary by more than 15 degrees between the floor and ceiling.

These efficiencies helped the Carleton project team capture several LEED points, which are necessary to achieve its Gold-level certification goal. According to Potvin, the radiant heating system earned the project credits in two LEED categories:

• Indoor environmental quality. The system provided a thermal comfort zone for each resident unit; and
  
  
• Energy and atmosphere. The system helped to reduce the building’s energy consumption.

The radiant system required more than 68,800 linear feet of Wirsbo crosslinked polyethylene hePEX plus tubing to heat the 91,000 gross square footage of the two dormitories. Installation was overseen by Egan’s general foreman Dennis Kieffer and eight crew members, who laid 1-inch foam sheets on top of a vapor barrier, which protected the insulated concrete flooring. Tubing was then stapled to the foam between 6-inch to 12-inch on center, depending on heating load, and covered with 3 inches of concrete.

“During each stage of the final concrete pour and before the floor was set and cured, we pressurized the tubing so we could immediately identify and replace any portion that was inadvertently punctured,” explains Kieffer. “Other than the scale of this project, the process is as straightforward as any radiant heat installation.”

Egan Co. has been the installing contractor on several radiant heating projects, including those with radiant ceiling panels. “While we expect radiant heat applications to grow in the future,” says Carver, “the current economic reality has put many projects on hold.”

Sustainable Design Features

Peter A. Potvin, P.E., LEED AP, a principal at LKPB Engineers and the project's design engineer

In designing the HVAC system, Potvin says the team agreed not to air-condition the residence halls, since few students stay on campus during the summer.

“Not air-conditioning the dormitories was clearly the most sustainable HVAC decision,” remarks Steven Spehn, director of the college’s facilities. “While our Minnesota climate requires heating buildings during most of the school year, our low summer occupancy rates enabled us to eliminate the need for a forced-air cooling system.” He adds that some areas, such as residence hall assistants’ rooms, do have stand-alone air-conditioning units.

Simple radiant zoning enables students to control their individual room thermostats, while the two buildings’ overall energy usage will be recorded (and displayed publicly) through a real-time resource monitoring system, notes Spehn, alluding to one of the project’s many other energy-saving technologies.

Many sustainable and LEED options are incorporated into the project, including solar domestic water heating. Other dorm features include the use of photovoltaic panels to directly convert the sun’s energy, air-to-air heat recovery technology, high-efficiency lighting, and a parking lot constructed from porous pavers to minimize stormwater run-off. 

Construction for the $27.5 million project began in May 2008 and is expected to be completed by late summer 2009 — in time to welcome the fall freshmen class, pizza boxes and all.

Egan Co — 64 Years Young

the west side of the new Memorial Hall

Brooklyn Park, Minn.-based Egan Co. started out as a three-person plumbing shop in the 1940s. In 1945, with $3,000 in start-up money, brothers Costney and Bill joined their father Joseph Egan, and formed Egan & Sons Plumbing and Heating Co. In 1960, Egan Electrical was established; in 1988, Egan Automation was founded; and in 1997 the company formed InterClad Curtain Wall Co. Egan set up an industrial controls group in 2002, as well as purchased Nietz Electric in Rochester, Minn., to expand into another geographic market.

The company has diversified into pipe and metal fabrication, electrical, fire/life/safety, industrial controls, automation systems, aluminum curtainwall, doors, glass and glazing. It boasts more than 700 employees at three locations representing more than a dozen trade unions.

Estimated 2008 revenue for Egan Cos. is $147 million. Mechanical accounts for 38 percent of the business, electrical is 37 percent and systems (which includes curtainwall) is 25 percent.

In March of this year, a new CEO was named as Craig Sulentic retired — Jim Malecha, who will also remain as president of the company. Rounding out the management team is Bill Marshall, executive vice president, mechanical; Duane Hendricks, executive vice president, electrical; Bill John, executive vice president, InterClad; and Jack Galvin, vice president, electrical.

Egan Co. has consistently placed in Plumbing & Mechanical’s annual Pipe Trades Giants ranking, coming in last year at No. 76.

The company credits its success to a loyal, highly skilled staff; a healthy environment; and partnerships with many successful general contractors, building owners and property managers in the industry.

The Greening Of Egan

Egan Co. has its own LEED-certified building — the new Nietz office/warehouse facility in Rochester, Minn., recently received LEED certification (the first in Rochester), says Jim Carver, general manager of Nietz – Mechanical. The building has many windows to “harvest the light,” uses recycled carpet and flooring, and low-VOC paint. Motion detectors are installed to turn lights on when someone enters the room, and turns lights off when no motion in the room is detected.

Egan also recycles paper and has eliminated the use of Styrofoam cups in the lunchroom.

Today’s economy has driven some of Egan’s green initiatives.

“The recession has affected Egan in the same way as most energy-conscious companies,” Carver explains. “We are trying to consume less and sell more energy-efficient services and products including alternative energy solutions like solar voltaic, thermal heat pumps, wind, and building recommissioning studies and programs.”

He says that Egan Co. has formed an Alternative Energy Task Force to study the market, determine feasibility and pursue opportunities that fit with the company.

 The company bought two hybrid cars for staff members to use on business calls and it has replaced a number of its larger “gas-inefficient” trucks with more efficient “mini trucks.” Egan also recycles scrap iron and other construction materials when possible.