This 10 story, 313,000 square foot Arden Realty building at 5200 West Century was a see-through building when it was purchased, with less than 30% occupancy.  Even with these low levels of occupancy, the HVAC system was unable to provide the necessary cooling to the tenants, and the system static pressure routinely ran at less than 0.5" discharge static pressure with the fans at full pitch and power demand, with a design discharge static pressure of 2.0".

After a building renovation, there were several large leases being negotiated with high occupant density tenants, typically over 15 people per thousand square feet, and these leases could not be let unless the HVAC system could be cost effectively upgraded, in a very short period of time.

ROI teamed up with a well known design-build contractor, Control Air Conditioning Service Corporation, and acted as their design firm for the project.  This team competed against two other large design-build teams, and were able to propose a system retrofit that cost substantially less than the other teams, while using less energy, and with minimal tenant disruption

ROI designed a retrofit to convert the HVAC  system to operate as a low temperature air distribution system, allowing the main duct risers and fan systems to be re-used.  The system is capable of providing supply air as cold as 39°F on peak load days, without ductwork condensation issues, but it typically operates at 55°F to 65°F for most of the year, due to dynamic optimization routines made possible through the new Siemens DDC system.

The total annual chiller plant efficiency has been hovering at less than 0.60 kW per ton, including the chillers, chilled water and condenser water pumps and the cooling tower fan energy. (Graphs for this building)

The supply fan energy utilized by our design is roughly half that compared to the solutions offered by the competing design build teams. 

Now the system is capable of maintaining comfort for up to 450 people per floor, 60% greater than HVAC systems are typically designed to handle, and the facility is approximately 98% leased.

We have assisted Arden Realty and Real Energy Incorporated with the installation of a 400 kW cogeneration system at this site. The CoGen System provides approximately 25% of the annual electricity consumption and over 90% of the heating hot water.

5200 West Century | 600 B. Street | 701 B. Street
8383 Wilshire | Arden Norwalk