Building the Southwest since 1974

IMCOR (Interstate Mechanical Corporation)

Interstate Mechanical Corporation (IMCOR), which is consistently ranked among the top mechanical contractors both in Arizona and nationally by magazines including Business Journal, Arizona Business, Southwest Contractor, and Engineering News-Record (ENR), has humble roots. It was started as a backyard business begun by Merle (Rick) Karber, Jr. as Karber Sheet Metal in 1973, and was renamed Karber Air Conditioning when Rick’s brother, Mike joined the Company in 1974. Today, IMCOR is one of the Southwest’s largest non-union mechanical services subcontractor, occupying an entire city block in Phoenix, Arizona.

IMCOR was built on old-fashioned teamwork, with an emphasis on family. In fact, 1978 was a turning point for the small business started by the brothers, when their father, Merle Karber, Sr., who had recently retired from a thirty-year career in the air conditioning industry, joined the Company to assist in project management, estimating, and job cost accounting. Merle, Sr.’s experience in the industry and dedication to his sons’ success accelerated the Company’s growth and profitability.

That same year, William (“Bill”) P. Mason joined the Company, which was at the time still a small, union sheet metal company. Bill’s remarkable legacy from service technician to Company President parallels the Company’s staggering growth. Bill recalls: “I had completed the refrigeration and air conditioning course at community college. I had an associate arts degree, and I became a welder and a fabricator and a mechanic. Even though I started as a service technician, I also understood what it took to manufacture the sheet metal components that we install.”

In the early 1980s, the mechanical industry in Arizona was transformed when the Arizona Supreme Court ruled that prevailing wage laws that were typically applied to public works projects were unconstitutional. This meant that open shop contractors, which were not subject to collective bargaining agreements and union wages and benefits, were able to bid work at lower prices. Karber Air Conditioning experienced difficulty in remaining competitive in that environment, so the Karber brothers started another air conditioning company, this time an open shop, and named it IMCOR.

Mason, who had been a pipefitter and plumbing superintendent with Karber Air Conditioning, became a project manager at IMCOR. In Mason’s second year as project manager in 1990, he recalls that he managed the work at Phoenix City Hall, a twenty-story high-rise. “I was in my thirties then,” he says, “and it was interesting and fun. We did a great job on that project; it is one of my proudest achievements.” City Hall, however, was not Mason’s only significant project: “I managed some difficult jobs, such as a hospital’s steam relocation, where we removed every one of the old boilers that dated from the 1950s. The piping for a new boiler plant was built remotely with underground lines to the hospital and the same with the chilled water system, which was a three-year job.” Like IMCOR, Mason continued to learn from his experience and adapt to changes in the industry.

“We’ve done several challenging projects over the years,” Mason says, recalling with pride the Sky Harbor International Air Traffic Control Tower, which the Company worked on in 1987. “All the piping and plumbing was prefabricated. And we supplied the cab portion of the control tower that was a couple of hundred feet in the air and only had a small thirty- or forty-foot shaft connecting it to the ground with the TRACON (terminal radar approach control) building below, which supported the computerized networking and communications systems utilized in the air traffic control tower. The TRACON building required specialized cooling and heating and humidity control.” Since then, IMCOR has been involved with every major expansion and renovation at the airport.

“Another project we performed, that was a tough one, was an ice storage tank in downtown Phoenix.” This project, Mason says, was built underground, below a major street in downtown Phoenix, and involved multiple 1,000- and 2,000-ton chillers. At the same time, IMCOR was doing the Phoenix Convention Center, which involved thirty-six-inch pipe from the underground chilled water plant up to the roof of the convention center several hundred feet away, a challenging installation process. “It was difficult to get the rigging up in the air, and the installation on the underground portion was even tougher with the thermal storage ice generating coils being rigged into the ice storage tanks. The project required additional pre-fabrication of piping because there was not enough space in the tank to build the pipe in. We had to fabricate it ahead of time and bring it in large sections to connect the ice building coils,” he explains.

“It was fed with glycol piping that ran at 18 Fahrenheit to build the ice on the external tubes of the coil, by freezing the water in the storage tank at night when the electricity is less expensive, and then slowing down the operation in the afternoon when everyone is running the AC at maximum output and cost. During the day, the large chillers are shut off, and they circulate water through the ice storage tank, depleting the ice, chilling the water and pumping it out through multiple buildings downtown to cool them.”

Always ready for a new challenge, Mason advanced to the position of Vice President of the Company’s Facilities Services Group during the mid-1990s, a multi-faceted division of IMCOR that takes on special projects and includes design, retrofit, installation, service, and maintenance of any heating, ventilation, or air conditioning (HVAC) or plumbing system. The projects are “performed in-house and involve work in a lot of hospitals and for manufacturers of components for technology providers and medical devices, such as pacemakers,” Mason explains.

Rick Karber continued as the President of IMCOR until 2001. Upon Rick’s retirement, Mason became President, completing his ascent from service technician, where he continues to lead today.

IMCOR has also continued to expand and improve, now consisting of five divisions. “First, there’s our Construction Division, which performs plumbing, piping, sheet metal, and process piping. We fabricate all our sheet metal, prefabricated hydronic piping spools, and plumbing spools,” Mason tells us. “That’s something that few others do. Our competitors purchase materials from third party fabricators, leaving them vulnerable to output and quality issues. IMCOR is capable of building in excess of 40,000 pounds of sheet metal products a week for sheet metal ductwork. As far as piping goes, our prefabrication plant has several mechanical positioners, with state-of-the-art wire fed welders. We also have a plumbing prefabrication shop, where we assemble a battery of fixture supports. When coupled with our in-house BIM (building information modeling) department and 3D drafting, we have everything we need to do to be on the leading edge of prefabrication.”

The Company’s HVAC Service Group performs startups and preventative maintenance on many of the projects IMCOR installs, and IMCOR also maintains a sister Plumbing Service Group that handles preventative maintenance contracts for all types of plumbing applications, including grease waste drains, domestic water systems, and sewage ejection pumps for hotels, hospitals, high-rise, commercial, and industrial buildings.

IMCOR’s Facility Services Group continues to focus on in-plant work, which is typically owner direct. These types of projects, in addition to industrial and manufacturing environments, also include health care and other mission critical facilities. “Any work in hospitals has to be carefully pre-planned with a specific MOP (method of procedure) that we put together, and as necessary, we set up a tent around an infection control area, so we are not contaminating anything in the area we’re working in. Everything in the project area has to be roped off, with the systems specifically identified, shut down, and then brought back up carefully so as not to contaminate any of the adjacent areas. This is similar to how we work on the cooling, heating, and dehumidification needed in the clean rooms where pacemakers and other microelectronic devices are built.”

The fifth division is the Manufacturing Group, where IMCOR utilizes structural and lightweight steel in a lean manufacturing environment “to build modules for workload in data sites, like a cell tower site,” Mason says. “We fabricate them here in units that are as much as fifty feet long by ten to twelve feet wide, ship them to the job site, and install them as single units or bolt several of them together to create a completely prefabricated system ready for use.” In addition, IMCOR’s Manufacturing Group builds customized data centers, restroom pods, mechanical, electrical, and plumbing (MEP) racks, hospital headwalls, and ornamental iron for commercial buildings.

Like its President, IMCOR never backs away from a challenge. When we caught up with Mason for this interview, he was overseeing completion of a four-year project at Arizona State University (ASU), which involved a complete remodeling of the school’s four-story football stadium. Since it had to be available for the football season of September through Thanksgiving, each of the four sides had to be demolished and built back up between December 1 and August 31, over a period of four years.

As we learned, constructing a stadium is about a lot more than installing bleachers. “On the west side alone, there are 250 separate toilets, urinals, and sinks, so a lot of plumbing on every level, and there’s a lot of ductwork that feeds the concession kitchens,” Mason explains. “They require cooling, heating, domestic hot and cold water, drains, waste, and vents and a way to take grease exhaust from the kitchens. All of this has to be fitted around the seating areas, with washrooms and kitchens on every level,” he says.

“The ASU stadium was built in the 1950s, and while some work had been performed on it over the years, it was due for a complete remodeling. However, the logistics are daunting; it’s on the side of a hill with very difficult access. There are several steel I-beams that allow the stadium to cantilever out, but that is tough for the mechanical system installation as there is not much room for it – all the sheet metal, hydronic piping, grease ducts, and plumbing. We can’t run a grease duct all the way up and out the roof, because there is no roof, so we had to install a grease scrubber above each concession area to remove the grease and clean the air.”

IMCOR is currently working on another ASU-related project, building a twenty-story adult living facility on the ASU campus. The complex is about fifty percent complete, with fourteen-inch cooling condensing water lines for the HVAC and water source heat pumps going to all the apartments.

Mason says the secret of IMCOR’s success is its people. Many of IMCOR’s staff have been with IMCOR for twenty, thirty, or even thirty-five years because of the Company’s commitment to teamwork, family and its community. Further, mirroring his own journey, Mason has always sought to promote from within.

“Each employee is presented with a clear path for advancement, together with specific goals for achieving that advancement,” Mason states. “This gives our team direction and motivation, together with the possibility for a long career at IMCOR. I’m the President,” says Mason, “but without everyone who works here in different capacities, IMCOR wouldn’t be successful. A company has to rely on all of the employees, and I work for them rather than the other way around.”

Another example of its commitment to its team is IMCOR’s in-house apprenticeship program, which is accredited through the community college system. Mason is particularly fond of the Company’s apprenticeship program: “We train as many people as we can to work for us. Apprentices learn to make connections on piping and ductwork, and as they work their way to journeyman level after four years, they continue to gain knowledge, and they, in turn, mentor apprentices while being mentored by a foreman. Then they can become a lead man and work into being a foreman and beyond that a superintendent. We try to maintain a positive work environment with mentoring happening every day at multiple levels.”

In fact, Mason credits the Company’s apprenticeship program for helping the Company to navigate the current labor shortfall in the industry. “We are faced with the fact that there is more work than there is labor, so we have to be selective in what projects we take on. However, we can be more ambitious with our workload due to our in-house training.”

Like its President, IMCOR also demands the best: “Our goal has never been to be the biggest mechanical contractor, but rather to be the best. That means we provide projects on time, on budget and with quality workmanship. Above all, we do it safely. Construction is unpredictable; it’s not a safe environment unless you make it that way. I’m proud to say that we’ve focused on safety over the years.”



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