111-03 77th Avenue, Forest Hills

A new outpatient hospital-type facility on a corner lot in Queens, built mostly below street level: three sub-cellars and a cellar holding the surgical suite, sterile processing, patient admission, staff areas, parking and the plant rooms, with clinic floors for examination, imaging and consultation above. Because the surgical suite sits deep underground, every system has to work without relying on the outdoors next door — outdoor air is delivered by ducts and rooftop units, drainage has to be pumped up to the street sewer, medical gases have to reach every operating room, and the fire protection has to lift city water pressure to the roof. All of it was designed to the NYC Construction Codes, the 2020 NYC Energy Conservation Code and the healthcare ventilation criteria for surgical spaces. Like every New York project, the design also has to satisfy the NYC Construction Codes and the city's energy code requirements.

Mechanical: we scheduled ventilation room by room for the whole building — about 27,800 ft² of rooms across four levels — and set four air changes of outdoor air per hour in each operating room, with MERV 13 filtration, pressure sensors and monitors on the surgical rooms and electric-steam humidifiers holding 50% relative humidity. Heating and cooling for the clinical spaces comes from a VRF heat pump system of six outdoor units totalling about 104 tons and more than 70 indoor units, backed by six 7-ton and one 16-ton gas-fired rooftop units with hot-gas reheat and three energy-recovery ventilators for fresh air. Electrical: we scheduled the power connection for every motor, heater and pump — voltage, phase, minimum circuit ampacity and overcurrent protection — from 460 V three-phase rooftop units to 120 V unit heaters. Plumbing and medical gas: domestic water through a triplex variable-speed booster set, two 100-gallon gas-fired water heaters with recirculation and thermostatic mixing valves, duplex sewage ejector and sump pumps for everything below the street sewer, and oxygen, nitrous oxide, vacuum and waste anesthetic gas outlets at all six operating rooms plus oxygen and vacuum at 13 pre- and post-operative beds. Fire protection: a wet sprinkler system with a combined sprinkler and standpipe riser, a second standpipe, a fire pump and jockey pump, dry-pipe zones for unheated areas and two street fire department connections, hydraulically calculated at about 520 gpm against the city hydrant test. We also prepared the COMcheck energy analysis, the backflow prevention applications for the fire and domestic services and the revised mechanical, plumbing and sprinkler sets for filing in 2024.