5.8 Mechanical Requirements for Special Spaces
United States Courthouse,
White Plains, NY
Courtrooms. Generally, each Courtroom and its respective ancillary areas coupled to the operation of the Courtroom shall constitute a primary zone. No more than two Courtrooms and their respective ancillary areas shall be supplied from the same air-handling unit and system. Refer to the U.S. Courts Design Guide published by the Administrative Office of the United States Courts (AOC) for specific requirements.
Auditoriums. Auditoriums shall have dedicated air handling units equipped with enthalpy economizer cycle. Units shall be designed with 80 percent diversity factor to maintain necessary temperature and humidity conditions under partial loads and partial occupancy. Provide dew point control. Dew point of supply air shall not exceed 10°C (50°F) dry bulb.
U.S. Marshals Service Areas. The U.S. Marshals Service area HVAC system shall be designed for continuous operation and shall be independently controlled and zoned. All ductwork and air circulation openings penetrating the secure area envelope, including prisoner circulation areas, shall be provided with security bars.
Detainee holding areas shall be negatively pressurized with regard to adjacent spaces and exhausted directly to the outdoors. Refer also to requirements of USMS Publication 64.
Firing Range. Special HVAC considerations will be required for firing ranges. A firing range shall be provided with a dedicated air-handling system. Heating and cooling supply air shall be delivered to the area along and behind the firing line for occupant comfort conditions and to maintain a positive pressure in this area relative to down range and target area. Powered exhaust air shall be extracted from down range and the target areas in sufficient quantity to remove smoke and maintain a clear line of vision to the target. Sixty percent of the total exhaust shall be extracted at a point approximately one third the distance from the firing line to the target area, and forty percent shall be extracted from above the target area. All exhaust air shall be filtered to preclude the emission of lead particulates and gunpowder residue into the atmosphere. Discharge of firing range exhaust air to outdoors shall be carefully located to prevent recirculation into the outside air intake of any HVAC system. Firing range systems shall be capable of continuous operation, isolated from other building systems.
Kitchens and Dishwashing Areas. Kitchens with cooking ranges, steam kettles, ovens and dishwashers shall be provided with dedicated make-up air and exhaust hoods/exhaust systems in accordance with latest edition of NFPA Standard 96 and ASHRAE Applications Handbook. All components of the ventilation system shall be designed to operate in balance with each other, even under variable loads, to properly capture, contain, and remove the cooking effluent and heat, and maintain proper temperature and pressurization control in the spaces efficiently and economically. The operation of the kitchen exhaust systems should not affect the pressure relation between the kitchen and surrounding spaces. Both supply air and makeup air shall be exhausted through the kitchen hood heat recovery system while a maximum of 30 percent of the exhaust air is made up from the space.
Floor drains must be provided at each item of kitchen equipment that requires indirect wastes, where accidental spillage can be anticipated, and to facilitate floor-cleaning procedures. Drains to receive indirect wastes for equipment should be of the floor sink type of stainless construction with a sediment bucket and removable grate.
Areas of Refuge. The area of refuge provided for the Judiciary in the event of emergency conditions shall be provided with adequate ventilation energized from the emergency power distribution system and sufficient heating capacity to maintain space temperature of 21°C (70°F) with design winter outdoor temperature. Provide separate air-handling unit to maintain positive pressure, relative to surrounding spaces, with heating-cooling coils and differential pressure sensing system.
Mechanical Rooms. All mechanical rooms must be mechanically ventilated to maintain room space conditions as indicated in ASHRAE 62, ASHRAE 15, and Table 5-1 of this chapter. Water lines shall not be located above motor control centers or disconnect switches and shall comply with requirements of NEC Chapter 1. Mechanical rooms shall have floor drains in proximity to the equipment they serve to reduce water streaks or drain lines extending into aisles.
Chiller Equipment Rooms. All rooms for refrigerant units shall be constructed and equipped to comply with ASHRAE Standard 15: Safety Code for Mechanical Refrigeration. Chiller staging controls shall be capable of DDC communication to the central building Energy Management System.
Electrical Equipment Rooms. No water lines are permitted in electrical rooms, except for fire sprinkler piping. Sprinkler piping lines must not be located directly above any electrical equipment.
Communications Closets. Communications closets must be cooled in accordance with the requirements of EIA/TIA Standard 569. Closets which house critical communications components shall be provided with dedicated air-conditioning systems that shall be connected to the emergency power distribution system.
Elevator Machine Rooms. A dedicated heating and/or cooling system must be provided to maintain room mechanical conditions required by equipment specifications, and in accordance with Table 5-1 of this chapter.
In the event the building is equipped throughout with automatic sprinklers, hoistway venting is not required.
Emergency Generator Rooms. The environmental systems shall meet the requirements of NFPA Standard 110: Emergency and Standby Power Systems and meet the combustion air requirements of the equipment. Rooms must be ventilated sufficiently to remove heat gain from equipment operation. The air supply and exhaust shall be located so air does not short circuit. Generator exhaust should be carried up to roof level (GSA preference) in a flue or exhausted by way of compliance with the generator manufacturer’s installation guidelines. Horizontal exhaust through the building wall should be avoided.
UPS Battery Rooms. Battery rooms must be equipped with eye wash, emergency showers and floor drains. The battery room must be ventilated/exhausted directly to the outdoors at a rate calculated to be in compliance with code requirements and manufacturer’s recommendations, and the exhaust system must be connected to the emergency power distribution system. Fans shall be spark-resistant, explosion proof, with motor outside the air stream, ductwork to be negative pressure system of corrosion-resistant material, with exhaust directly to outdoors in a dedicated system. Acoustical enclosures shall be provided to maintain a maximum NC level of 35. Coordinate with electrical design specifications to include HVAC support equipment in UPS extended servicing agreements.
Loading Docks. The entrances and exits at loading docks and service entrances shall be provided with a positive means to reduce infiltration and outside debris. Loading docks must be maintained at negative pressure relative to the rest of the building.
24-Hour Spaces. All areas designated as requiring 24-hour operations shall be provided with a dedicated and independent HVAC system. All spaces handling BAS computer processing of Fire Alarm Monitor and Control Systems, Security Monitor and Control Systems and/or energy monitoring and control systems shall be provided with dedicated HVAC systems to maintain temperature, humidity and ventilation requirements at all times. Twenty-four hour systems shall have dedicated chiller(s), cooling tower(s) boiler(s), and associated pumping systems. However, central system(s) can be used to provide chilled water and hot water during the normal operating hours, or as a backup for the 24-hour system(s). Twenty-four hour systems with a capacity of up to 50 tons should be configured with an air-cooled chiller. In the event the building’s 24-hour operation load, including the dedicated perimeter ventilation system, exceed 50 tons, the cooling systems may be combined with a central system of which a dedicated central chilled water supply loop shall be provided along with 24-hour chiller.
Artwork. In general, it is important to keep within an RH range of 30 to 70%. In a hot and dry geographic region it makes sense to maintain a range that errs on the low side (20 to 40%), while in semitropical climates a range of 55 to 75% may be practical.
Please consult Chapter 4.1, Installation Standards, of the Fine Arts Program Desk Guide for additional information.
Fire Protection and Smoke Control. Refer to Chapter 7: Fire Protection Engineering, for fire protection and smoke control requirements.