Trailer 1888 at Lawrence Livermore National Laboratory is divided into north and south sides. This scope of work was to replace the AC units on the rooftop of T1888 south building, and to provide air balancing of both the north and south side AC units (the north AC units had been replaced under a separate contract). Nine existing rooftop AC units (heat pumps) were removed. The units were delivered via crane tightly wrapped from the roof to the laydown area to prevent asbestos containing material on the unit and their sleepers, and the units’ refrigerant from becoming friable or escaping into the atmosphere.
Eight new owner-furnished AC units and their curbs were transported to the roof by crane, curbs set and units installed. The client provided all roof patching. A roof platform was built and a disconnect switch frame was constructed to service the new units. New supply and return branch ductwork with grilles and diffusers was installed above the ceiling inside the trailer. Penetrations were cut through the existing glulam roof beams to accommodate the new duct runs. New operable thermostats were installed, programmed and configured for the new roof units.