Project:
Freddie Mac, McLean, Virginia
The Challenge:
Costing about $8.9 million, the Freddie Mac project entailed construction of a 400,000-square-foot, five-story office building.
ColonialWebb Contractors was instrumental in the installation of all plumbing, electrical and HVAC systems. The complexity of the project required 44 separate county permits and uncovered a few difficult issues.
Our Approach:
For plumbing, we set the systems for core bathrooms with electronic flush valves, installed piping for the large kitchen and multiple break rooms, and designated a separate café and deionized water system.
The HVAC system was a Washington, D.C., area first – a York International underfloor VAV air distribution system. The system distributes air to four levels of office space, which provided great challenges during installation. We collaborated with the floor contactors for the ductwork installation and flexible run-outs to the grilles. Our coordination was imperative to ensure minimal damage as it would have been easy for other contractors on the job to inadvertently damage our ductwork and equipment.
The pressurized floor also boasts of being one of the nation’s first to have metal round floor grilles installed. These grilles had not been produced at the time of the project bid, thus providing a challenge to meet the critical installation date. Manufacturers from Germany to Canada battled it out to be the first provider of the 2,600 grilles needed for the task.
We interfaced the under-floor HVAC with the Andover Building management system and the automatic temperature control system. Our massive 12-foot-wide ductwork in the mechanical penthouses created additional logistical challenges in detailing, fabrication, delivery and installation. Also in the east and west mechanical penthouses, we installed:
- Five custom Ventrol built-up air handling units
- Three chillers
- Three cooling towers
- Multiple pumps
- Heat exchanger
ColonialWebb service electricians from our Richmond and D.C. area offices laid control wiring and conduit, and our HVAC service technicians retrofitted the Liebert air conditioners with custom humidifiers.