Ventilation and Indoor Air Quality

99 W Hawthorne Ave, Valley Stream, NY


This commercial office space needed to fix the chilled water system, which had prematurely deteriorated due to poor construction.

MEP designed the new chiller to increase capacity and operating efficiency, and recommended upgrades to existing structures while retaining as much of the current components as possible to reduce costs.

Facility Description

This 36,000 square foot building is composed of six stories of commercial office space. The building’s heating demand is served by a boiler plant located within the building.

However, the chilled water system was added on to the building and is approximately 20 years of age. The cooling tower is located on the roof of the building and the chiller is located on a grade level single story addition of 8.5’x17.5’ in size. The chiller room’s poor roof construction and the three six foot low commercial grade access doors provide poor protection from the elements. As a result, the existing 100 ton gas-fired absorption chiller has deteriorated prematurely.

Project Origin and Goals

The objective of 99 W. Hawthorne LLC was to replace the existing chiller with a larger one as the building’s demand has increased since twenty years prior. The budget did not allow for chiller room modifications of any kind.

MEP was the prime consultant for this project retained by the client to analyze, design construction documents, provide construction services, and conduct the necessary final inspections for the Department of Buildings.

Site Findings and Solutions

Chiller — MEP designed the installation of a new 135 ton centrifugal chiller within the allocated chiller room and maintained all provisions for maintainability. The new chiller provided the facility with 35% extra capacity and increased operating efficiency by 12%. The chilled water pumps were in good operating condition but the impellers had to be replaced to provide the new minimum flow through the refrigerating machine. The cooling tower and corresponding condenser water pumps were of adequate capacity to accommodate the new load.

Code compliance — New refrigerant alarms were specified as the chiller room was not equipped with any warning devices.

Power — A new service was connected to the main switchgear to serve the chiller room and associated appurtenances.