uilt in the 1950's, 555 Fifth Avenue is a 175,000 sq. ft., 20 story office building located in New York City.  In 1996 the Owners, ATCO Properties and Management Inc. became aware of a need to upgrade the aging HVAC system for the building.  In addition to age and deterioration of the systems, increased equipment loading due to the proliferation of personal computer use and other office technology enhancements left the systems with insufficient capacity. 

In 1989 Kallen & Lemelson had designed the replacement of one of the building's chillers and subsequently had designed for the replacement of two of the building's air handling units and the addition of a cooling tower.  However a more organized approach was now needed to maintain the quality of the environment as a Class A Office Building on Fifth Avenue in the heart of Manhattan demanded.  As a result Kallen & Lemelson provided engineering services to formulate a Master Plan for the upgrade of the HVAC system.

The project tasks for this Master Plan included cooling load calculations, and analysis of air handling unit capacities, existing air handling unit capacities were determined and compared to the calculated loads.  The basic premise of the project was increasing the HVAC system capacity to handle a 6 watt/SF lighting and equipment load and renovation of the chiller plant.

The existing chiller plant consisted of three 100 ton each reciprocating compressor chillers and a 270 ton electric centrifugal double bundle condenser chiller (which provides heat recovery and had been designed by Kallen & Lemelson in 1989).  The three reciprocating chillers had exceeded their useful life and need to be replaced.  Options for replacing the reciprocating chillers, expanding the plant capacity to 800 tons and replacing the refrigerant in the 270 ton chiller were analyzed.  Options included electric centrifugal, absorption chillers and electric screw chillers.  Limitations included available MER space and the fact that the chiller room is below grade with poor accessibility.

Several options for increasing air handling unit capacity and upgrading the secondary chilled water distribution system were analyzed.  K&L engineers also provided analysis of construction phasing and scheduling for the recommended Master Plan.  Our analysis included estimating a budget construction cost, operating cost and identifying intangible issues for each option.

The Master Plan was adopted by ATCO Properties and management and upgrading was planned to be phased in over the next 10 to 15 years.  Implementation was paced based on cash flow and the need to maintain building occupancy.  Replacement/upgrading of air handlers and conversion from constant volume reheat systems to variable air volume systems was phased to coincide with tenant changeovers.

Specific projects that have been designed and implemented by Kallen & Lemelson since the Master Plan include the following:

• Replacement of remaining reciprocating chillers and expansion of the chiller plant to 800 tons by providing two new 270 tons each electric centrifugal chillers.
  
• Upgrading of the building's secondary chilled water distribution system.
  
• Replacement & upgrade of air handlers serving the 3rd, 6th, 7th, 8th, 9th, 15th , 16th, 17th, 19th, and 20th floors.
  
• Upgrading to variable volume system is ongoing as is the conversion to direct digital control and a building-wide computerized management system.
  
• Upgrade of electrical risers feeding air handling units.