Cator, Ruma & Associates was selected to provide mechanical design and contract administration for the HVAC upgrade at Colorado State University’s Bio-Hazards Research Building (BHRB). Cator, Ruma & Associates has a great deal of experience in the BHRB facility, having completed the original design in 2000, an expansion in 2008, and numerous small remodel projects over the years. Utilizing our extensive knowledge of the facility, we determined that the ideal way to perform the upgrades was to re-use the existing air handling units (AHUs) in place and replace the supply fans with new fan arrays to gain redundancy within each AHU.

In order to accomplish this upgrade, we first removed the existing boilers, DA tank, blowdown separator, and other supporting equipment. Then, the boiler flue was removed. The existing supply fans were replaced with new fan walls in AHU-1A and AHU-1B. The existing steam humidifier grid was replaced with a new Dri-Steam Ultrasorb, insulated grid and re-steam capability. All exhaust fans were replaced with new direct drive fans. A spare heat exhaust fan was provided and stored so that it can be installed in any of the three (3) BSL-3 zones. The motorized dampers at exhaust fans were replaced and new backdraft dampers were installed in addition to the motorized dampers. The VFDs for the fan wall and exhaust fans were replaced. The heating water heat exchangers were relocated down to the main boiler room floor level. The reheat circulation pump was relocated to a serviceable location. Stainless exhaust ducts were re-welded where spot welding was covered up by Alumi-grip tape. A new control system was provided, and the AHU coils were cleaned.