| (3) General mechanical requirements. This paragraph
contains common requirements for mechanical systems; steam and hot
and cold water systems; air-conditioning, heating and ventilating
systems; plumbing fixtures; piping systems; and thermal and acoustical
insulation. The facility shall comply with the requirements of this
paragraph and any specific mechanical requirements for the particular
unit or suite of the facility in accordance with §134.123 of
this title.
(A) Cost. All mechanical systems shall be designed
for overall efficiency and life cycle costing, including operational
costs. Recognized engineering procedures shall be followed to achieve
the most economical and effective results. In no case shall patient
care or safety be sacrificed for conservation.
(B) Equipment location. Mechanical equipment may be
located indoors or outdoors (when in a weatherproof enclosure), or
in separate building(s).
(C) Vibration isolation. Mechanical equipment shall
be mounted on vibration isolators as required to prevent unacceptable
structure-borne vibration. Ducts, pipes, etc. connected to mechanical
equipment which is a source of vibration shall be isolated from the
equipment with vibration isolators.
(D) Performance and acceptance. Prior to completion
and acceptance of the facility, all mechanical systems shall be tested,
balanced, and operated to demonstrate to the design engineer or his
representative that the installation and performance of these systems
conform to the requirements of the plans and specifications.
(i) Material lists. Upon completion of the contract,
the owner shall be provided with parts lists and procurement information
with numbers and description for each piece of equipment.
(ii) Instructions. Upon completion of the contract,
the owner shall be provided with instructions in the operational use
of systems and equipment as required.
(E) Heating, ventilating and air conditioning (HVAC)
systems. All HVAC systems shall comply with and shall be installed
in accordance with the requirements of National Fire Protection Association
90A, Standard for the Installation of Air Conditioning and Ventilating
Systems, 1999 edition, (NFPA 90A), NFPA 99, Chapter 5, the requirements
contained in this subparagraph, and the specific requirements for
a particular unit in accordance with §134.123 of this title.
(i) General ventilation requirements. All rooms and
areas in the facility listed in Table 3 of §134.131(c) of this
title shall have provision for positive ventilation. Fans serving
exhaust systems shall be located at the discharge end and shall be
conveniently accessible for service. Exhaust systems may be combined,
unless otherwise noted, for efficient use of recovery devices required
for energy conservation. The ventilation rates shown in Table 3 of
§134.131(c) of this title shall be used only as minimum requirements
since they do not preclude the use of higher rates that may be appropriate.
Supply air to the building and exhaust air from the building shall
be regulated to provide a positive pressure within the building with
respect to the exterior.
(I) Cost reduction methods. To reduce utility costs,
the building design and systems proposed shall utilize energy conserving
procedures including recovery devices, variable air volume, load shedding,
systems shut down or reduction of ventilation rates (when specifically
permitted) in certain areas when unoccupied, insofar as patient care
is not jeopardized.
(II) Economizer cycle. Mechanical ventilation shall
be arranged to take advantage of outside air supply by using an economizer
cycle when appropriate to reduce heating and cooling systems loads.
Innovative design that provides for additional energy conservation
while meeting the intent of this section for acceptable patient care
will be considered.
(III) Outside air intake locations. Outside air intakes
shall be located at least 25 feet from exhaust outlets of ventilating
systems, combustion equipment stacks, medical-surgical vacuum systems,
plumbing vents, or areas which may collect vehicular exhaust or other
noxious fumes. (Prevailing winds and proximity to other structures
may require other arrangements.) Plumbing and vacuum vents that terminate
five feet above the level of the top of the air intake may be located
as close as 10 feet.
(IV) Low air intake location limit. The bottom of outside
air intakes serving central systems shall be located as high as practical
but at least six feet above ground level, or if installed above the
roof, three feet above the roof level.
(V) Contaminated air exhaust outlets. Exhaust outlets
from areas (kitchen hoods, ethylene oxide sterilizers, etc.) that
exhaust contaminated air shall be above the roof level and arranged
to exhaust upward.
(VI) Directional air flow. Ventilation systems shall
be designed and balanced to provide directional flow as shown in Table
3 of §134.131(c) of this title. For reductions and shut down
of ventilation systems when a room is unoccupied, the provisions in
Note 4 of Table 3 of §134.131(c) of this title shall be followed.
(VII) Areas requiring fully ducted systems. Fully ducted
supply, return and exhaust air for HVAC systems shall be provided
for all general patient care areas and where required for fire safety
purposes. Combination systems, utilizing both ducts and plenums for
movement of air in these areas shall not be permitted. Such areas
include isolation rooms and food preparation areas.
(VIII) Ventilation start-up requirements. Air handling
systems shall not be started up and operated without the filters installed
in place. This includes the 90% efficiency filters where required.
Ducts shall be cleaned thoroughly by an air duct cleaning contractor
when the air handling systems have been operating without the required
filters in place.
(IX) Humidifier location. When duct humidifiers are
located upstream of the final filters, they shall be located at least
15 feet from the filters. Ductwork with duct-mounted humidifiers shall
be provided with a means of removing water accumulation. An adjustable
high-limit humidistat shall be located downstream of the humidifier
to reduce the potential of condensation inside the duct. All duct
take-offs should be sufficiently downstream of the humidifier to ensure
complete moisture absorption. Reservoir-type water spray or evaporative
pan humidifiers shall not be used.
(ii) Filtration requirements. All central air handling
systems serving patient care areas, including nursing unit corridors,
shall be equipped with filters having efficiencies equal to, or greater
than, those specified for those types of areas in Table 4 of §134.131(d)
of this title. Filter efficiencies shall be average efficiencies tested
in accordance with American Society of Heating, Refrigerating, and
Air-conditioning Engineers (ASHRAE), Inc., Standard 52, 1999 edition,
(relating to Gravimetric and Dust Spot Procedures for Testing Air
Cleaning Devices Used in General Ventilation for Removing Particulate
Matter). All joints between filter segments, and between filter segments
and the enclosing ductwork, shall have gaskets and seals to provide
a positive seal against air leakage. Air handlers serving more than
one room shall be considered as central air handlers. All documents
published by ASHRAE as referenced in this section may be obtained
by writing or calling the ASHRAE, Inc. at the following address or
telephone number: ASHRAE, Inc., 1791 Tullie Circle, N. E., Atlanta,
GA 30329; telephone (404) 636-8400.
(I) Filtration requirements for air handling units
serving single rooms requiring asepsis control. Dedicated air handlers
serving only one room where asepsis control is required, such as,
but not limited to, operating rooms, delivery rooms, special procedure
rooms, and nurseries shall be equipped with filters having efficiencies
equal to, or greater than, those specified for patient care areas
in Table 4 of §134.131(d) of this title.
(II) Filtration requirements for air handling units
serving other single rooms. Dedicated air handlers serving all other
single rooms shall be equipped with nominal filters installed at the
return air grille.
(III) Location of multiple filters. Where two filter
beds are required by Table 4 of §134.131(d) of this title, filter
bed number one shall be located upstream of the air-conditioning equipment,
and filter bed number two shall be downstream of the supply fan or
blowers.
(IV) Location of single filters. Where only one filter
bed is required by Table 4 of §134.131(d) of this title, it shall
be located upstream of the supply fan. Filter frames shall be durable
and constructed to provide an airtight fit with the enclosing ductwork.
(V) Pressure monitoring devices. A manometer or draft
gauge shall be installed across each filter bed having a required
efficiency of 75% or more including hoods requiring high efficiency
particulate air (HEPA) filters.
(iii) Thermal and acoustical insulation for air handling
systems. Asbestos insulation shall not be used.
(I) Thermal duct insulation. Air ducts and casings
with outside surface temperature below ambient dew point or temperature
above 80 degrees Fahrenheit shall be provided with thermal insulation.
(II) Insulation in air plenums and ducts. Linings in
air ducts and equipment shall meet the Erosion Test Method described
in Underwriters Laboratories, Inc., Standard Number 181 (relating
to Factory-Made Duct Materials and Air Duct Connectors). This document
may be obtained from the Underwriters Laboratories, Inc., 333 Pfingsten
Road, Northbrook, IL 60062-2096.
(III) Insulation flame spread and smoke developed ratings.
Interior and exterior insulation, including finishes and adhesives
on the exterior surfaces of ducts and equipment, shall have a flame
spread rating of 25 or less and a smoke developed rating of 50 or
less as required by NFPA 90A, Chapters 2 and 3.
(IV) Linings and acoustical traps. Duct lining and
acoustical traps exposed to air movement shall not be used in ducts
serving critical care areas. This requirement shall not apply to mixing
boxes and acoustical traps that have approved nonabrasive coverings
over such linings.
(V) Frangible insulation. Insulation of soft and spray-on
types shall not be used where it is subject to air currents or mechanical
erosion or where loose particles may create a maintenance problem.
(VI) Existing duct linings. Internal linings shall
not be used in ducts, terminal boxes, or other air system components
supplying operating rooms, delivery rooms, birthing rooms, labor
rooms, recovery rooms, nurseries, trauma rooms, isolation rooms,
and intensive care units unless terminal filters of at least 90% efficiency
are installed downstream of linings.
(iv) Fire damper requirements. Fire dampers shall be
located and installed in all ducts at the point of penetration of
a two-hour or higher fire rated wall or floor in accordance with the
requirements of NFPA 101, §18-5.2.
(v) Smoke damper requirements. Smoke dampers shall
be located and installed in accordance with the requirements of NFPA
101, §18-3.7.3, and NFPA 90A, Chapter 3.
(I) Fail-safe installation. Smoke dampers shall close
on activation of the fire alarm system by smoke detectors installed
and located as required by National Fire Protection Association 72,
National Fire Alarm Code, 1999 edition (NFPA 72), Chapter 5; NFPA
90A, Chapter 4; and NFPA 101, §18-3.7; the fire sprinkler system;
and upon loss of power. Smoke dampers shall not close by fan shut-down
alone.
(II) Interconnection of air handling fans and smoke
dampers. Air handling fans and smoke damper controls may be interconnected
so that closing of smoke dampers will not damage the ducts.
(III) Frangible devices. Use of frangible devices for
shutting smoke dampers is not permitted.
(vi) Acceptable damper assemblies. Only fire damper
and smoke damper assemblies integral with sleeves and listed for the
intended purpose shall be acceptable.
(vii) Duct access doors. Unobstructed access to duct
openings in accordance with NFPA 90A, §2-3.4, shall be provided
in ducts within reach and sight of every fire damper, smoke damper
and smoke detector. Each opening shall be protected by an internally
insulated door which shall be labeled externally to indicate the fire
protection device located within.
(viii) Restarting controls. Controls for restarting
fans may be installed for convenient fire department use to assist
in evacuation of smoke after a fire is controlled, provided that provisions
are made to avoid possible damage to the system because of closed
dampers. To accomplish this, smoke dampers shall be equipped with
remote control devices.
(ix) Make-up air. If air supply requirements in Table
3 of §134.131(c) of this title do not provide sufficient air
for use by exhaust hoods and safety cabinets, filtered make-up air
shall be ducted to maintain the required air flow direction in that
room. Make-up systems for hoods shall be arranged to minimize short
circuiting of air and to avoid reduction in air velocity at the point
of contaminant capture.
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