Fully welded round air-tight stainless steel distribution systems.

How does a contractor install HVAC and plumbing equipment for a state-of-the-art, multi-use biological sciences building that contains complex challenges – including confined space for utility systems and limited access to equipment, all compounded by multiple laboratory systems, poured-in-place concrete construction, and tunnel corridor requirements?

University Marelich Mechanical (UMM) met and exceeded these challenges. The company, based in Anaheim, Calif., designed, fabricated and constructed the HVAC and plumbing systems for the new four-story, 145,000-square-foot Biological Sciences building at the University of California’s Irvine campus. The LEED-registered (Leadership in Energy and Environmental Design) facility is awaiting LEED Silver certification and consists of laboratories, a vivarium to house small animals, faculty offices, a 400-seat lecture hall, and a mechanical area in the basement that houses the air handling units.

Fully welded round and rectangular stainless steel distribution systems.

Each area of the $13.9 million mechanical and plumbing project had its own unique design and demands for indoor air quality (IAQ) and conditioning. The project also had different types of equipment and areas that needed to be serviced, including confined, limited space to layout the ductwork and equipment. Also, due to the type of building and systems used, some areas did not allow access doors to reach the equipment. Instead, access was gained through the lights.

To surmount these hurdles, University Marelich Mechanical’s designers and detailers used the Building Information Modeling (BIM) NavisWorks software to produce a fabrication and installation package to resolve conflicts and minimize field issues. The result was zero change orders.

Air handling units were fitted into the limited space required (120” X 36”) leaving only 3 inches from the top of the duct to the slab above.

The various systems included high-plume dilution fume exhaust fans in the laboratories, air-tight stainless steel distribution systems, bundled Phoenix valve installations in the lab and vivarium, utility exhaust fan sets, bubble tight dampers, and HEPA filtration systems. The multiple labs required equipment hook-ups and exhaust hoods for bio-safety cabinets, bulk auto claves, necropsy tables, tunnel washers, cage washers, canopy hoods, bottle washers, and sterilizers.

The project required 36,185 man-hours of sheet metal field installation, detailing, and BIM coordination, and 9,162 man-hours of fabrication. System specifications and components included air handling units that provided 240,000 cubic feet per minute (cfm) of conditioned supply air, laboratory/vivarium exhaust (180,000 cfm), general exhaust (42,000 cfm), variable air boxes, distribution devices, 290,000 pounds of galvanized ductwork and 49,000 pounds of welded stainless steel ductwork.

The second floor lab the Bio Safety Level 3 Suite required special air changes monitored by a Phoenix control system. For safety, bubble tight dampers were provided on the suite's supply air and exhaust system, designed to close and isolate the air within the suite to keep it from escaping.

The second-floor laboratory was designed for special experiments and containment of airborne contaminates, which required special air changes, negative and positive pressures, and monitoring by a Phoenix control system. The fume exhaust duct system included two dedicated 10,000 cfm roof-mounted fume exhaust fans. Bubble tight dampers, designed to close upon loss of static air pressure and keep the air from escaping, were provided on the supply and exhaust air system that served each suite.

In addition to the laboratory fume exhaust fans, the design included six additional fume exhaust fans to serve the other laboratory areas with a total of 31,000 cfm each. These fume exhaust fans were mounted on a factory-built plenum with isolation and bypass dampers. The fume exhaust duct risers serving the lab areas terminated at the roof level.

Fully welded stainless steel rooftop exhaust fans that serve other labs with a total of 31,000 cfm each. Fume exhaust fans are combined into two sets of three fan assemblies mounted on a factory-built plenum with isolation and bypass dampers.

The project used a variety of sheet metal products. The Pomona, Calif.-based SMACNA member Superior Duct Fabrication began manufacturing ductwork for this project in December 2006. The company supplied 339,000 pounds of round and rectangular ductwork consisting of galvanized, aluminum, and stainless steel, from low-pressure round fittings to large stainless steel exhaust roof plenums. The stainless steel duct was pre-fabricated and assembled in spool sections to reduce field installation time. A 190-ton crane hoisted and rigged the heavy duct to the building’s roof.

Energy efficiency aspects of the job included air handlers with multiple fan wall technology that draw outside air from huge, 260-square feet, louver sections and two-story high galvanized gas station panel casings.

The benefits to the client included overcoming a challenge of access to equipment. Certain areas of the building did not allow access doors to reach equipment, so UMM gained access through the lights. This proved to be a challenge to all trades, which required intense weekly coordination meetings. Limited space requirements needed intensive field activity to coordinate installation sequencing so as not to hinder the erection of the building’s structural and enclosure components. In addition, the HVAC design was based around three 58,000 cfm air handling units. UMM’s sheet metal detailers were able to fit them into the limited space provided, leaving only three inches from the top of the duct to the slab above.