U. S. General Services Administration Office of the Chief
Facilities Standards (P100) Overview
The Facilities Standards for the Public Buildings Service (P-100) establishes
design standards and criteria for new buildings, major and minor
alterations, and work in historic structures for the Public Buildings
Service (PBS) of the General Services Administration (GSA). This document
contains policy and technical criteria to be used in the programming,
design, and documentation of GSA buildings.
The Facilities Standards is a building standard: it is not a guideline,
textbook, handbook, training manual, or substitute for the technical
competence expected of a design or construction professional.
5.8 HVAC Components
UV-C Emitters / Lamps
Ultraviolet light (C band) systems must be incorporated in all AHU
containing cooling coils. The UV-C lamps must be installed downstream of the
coils and above the condensate pans. UV-C systems must be designed for the
minimum irradiance required to prevent the growth of microorganisms. Ozone
concentrations in the discharge air from the UV-C system must not exceed 50
ppb (see Section 5.3). Systems must be specifically manufactured for this
intended use. Safety interlocks must be provided on all access panels/doors.
AHUs large enough for personnel entry must contain a provision for the
deactivation, isolation, and locking out of the system power source in
addition to safety interlocks provided. One or more sight glasses must be
located to allow maintenance personnel to safely determine lamp operation.
Filters and Filter Sections
Air filtration must be provided in every air-handling system.
Air-handling units must have a pre-filter and a final filter, each located upstream of the cooling and heating coils. The
filter media must be fabricated so that fibrous shedding does not exceed
levels prescribed by ASHRAE Standard 52.2-2007. The prefilters must have a
MERV of 8, and the final filters must have a MERV of 13, as defined in
ASHRAE Standard 52.2-2007. Filter racks must be designed for a maximum
bypass leakage air around the filter media of 0.5 percent of the design
supply airflow rate. Filters must be sized at 2.5 m/s (500 fpm) maximum face velocity.
The filter housing and all air-handling components downstream of the filter
housing must not be internally lined with fibrous insulation. Double-wall
construction or an externally insulated sheet metal housing is permitted.
The filter change out pressure drop, not the initial clean filter rating,
must be used in determining fan pressure requirements. Differential pressure
gauges and sensors must be placed across each filter bank to allow quick and
accurate assessment of filter loading as reflected by airpressure loss
through the filter, and the sensors must be connected to the BAS.
Where occupancy requirements or building functions are likely to generate
airborne particles, vapors, or gases that result in concentrations exceeding
those in Section 5.3, special air filtration or air cleaning components must
be provided for the supply and return air, or dedicated and localized
exhaust systems must be used to contain these contaminants.
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