This 540,000 square foot facility was chronically short of cooling capacity, and had been having problems meeting the cooling load for over ten years prior to our involvement.  The penthouse supply fan systems were routinely at full pitch and full fan amps by 10:00 A.M. if the weather was 72°F or higher.  Above 80°F ambient, the supply air temperature rose almost proportionally with the ambient conditions.

The building is in close proximity to the Pacific ocean, and had been designed with aluminum finned cooling coils.  The fins would fall off in your hands if you touched them, due to corrosion.  Salt laden air and standard, untreated aluminum finned coils do not play well together.

ROI engineered a weekend conversion from a vane-axial fan system discharging into a plenum, to a plenum fan system located within the discharge plenum itself.  The deteriorated cooling coils were replaced with treated aluminum fin coils having 300% greater surface area. 

We were able to remove the inlet and discharge sound traps, and coupled with other fan system modifications, were able to remove over 2" w.c. of pressure losses from the air distribution system.

The larger coil surface allows us to provide 46°F supply air on peak load days, and the combination of the reduced pressure losses and lower supply air temperatures has allowed an overall site energy reduction of 11%, while serving peak cooling loads that are 30% greater than could be served previously.

We are in the process of working with Arden Realty and RealEnergy Incorporated to install a 600 kW cogeneration system, with 150 tons of absorption chiller capacity at this site.