To facilitate equipment access, maintenance, removal and
Roof-Mounted Equipment. No mechanical equipment
replacement, a freight elevator stop shall be provided to
except for cooling towers, air-cooled chillers, evaporative
serve each floor housing HVAC systems and equipment.
roof of the building. Access to roof-mounted equipment
Where stairs are required, they must allow for safe
shall be by stairs, not by ship's ladders.
transport of equipment and components. Ship's ladders
are not permitted for access and maintenance of any
Housekeeping Pads. Housekeeping pads shall be at least
152 mm (6 in) wider on all sides than the equipment they
support and shall be 152 mm (6 in) thick.
Vertical Clearances. Mechanical equipment rooms shall
have clear ceiling heights of not less than 3.7 m (12 ft).
Mechanical Rooms. All mechanical rooms must be
Catwalks with stairways shall be provided for all
mechanically ventilated to maintain room space
equipment that cannot be maintained from floor level.
conditions as indicated in ASHRAE 62, ASHRAE 15, and
Where maintenance requires the lifting of heavy parts
Table 5-1 of this chapter. Water lines shall not be located
[45 kg (100 lb) or more], hoists and hatchways shall be
above motor control centers or disconnect switches and
shall comply with requirements of NFPA 70 Chapter 1.
Mechanical rooms shall have floor drains in proximity to
Horizontal Clearances. Mechanical rooms shall be
the equipment they serve to reduce water streaks or drain
configured with clear circulation aisles and adequate
lines extending into aisles. Mechanical rooms shall not
access to all equipment. The arrangement shall consider
be used as return air, outdoor air, or mixing plenums.
the future removal and replacement of all equipment.
Mechanical equipment rooms must be designed in
The mechanical rooms shall have adequate doorways or
accordance with the requirements of ASHRAE Standard
areaways and staging areas to permit the replacement and
15: Safety Code for Mechanical Refrigeration.
removal of equipment without the need to demolish walls
or relocate other equipment. Sufficient space areas (noted
Chiller Equipment Rooms. All rooms for refrigerant
by outlining manufacturer's recommendations) for
units shall be constructed and equipped to comply with
maintenance and removal of coils, filters, motors, and
ASHRAE Standard 15: Safety Code for Mechanical
similar devices shall be provided. Chillers shall be placed
Refrigeration. Chiller staging controls shall be capable of
to permit pulling of tubes from all units. The clearance
DDC communication to the central building Energy
shall equal the length of the tubes plus 610 mm (2 ft). Air-
handling units require a minimum clearance of 762 mm
(2 ft 6 in) on all sides, except the sides that filters and coils
Electrical Equipment Rooms. No water lines are
are accessed, where clearance shall be equal to the length
permitted in electrical rooms, except for fire sprinkler
of the coils plus 610 mm (2 ft).
piping. Sprinkler piping lines must not be located directly
above any electrical equipment.
132 F A C I L I T I E S S T A N D A R D S
5.7 Mechanical and Service Space Requirements
Revised March 2005 PBS-P100