Page 44 - 2018_IMC

GENERAL REGULATIONS

10. Access to ladders shall be provided at all times. of discharge of not less than one-eighth unit vertical in 12
units horizontal (1-percent slope). Condensate shall not
Catwalks installed to provide the required access shall be
not less than 24 inches (610 mm) wide and shall have railings discharge into a street, alley or other areas so as to cause a
as required for service platforms. nuisance.
Exception: This section shall not apply to Group R-3 307.2.2 Drain pipe materials and sizes. Components of
occupancies. the condensate disposal system shall be cast iron, galva-
nized steel, copper, copper alloy, cross-linked polyeth-
306.5.1 Sloped roofs. Where appliances, equipment, fans
or other components that require service are installed on a ylene, polyethylene, ABS, CPVC, PVC, or polypropylene
roof having a slope of three units vertical in 12 units hori- pipe or tubing. Components shall be selected for the pres-
zontal (25-percent slope) or greater and having an edge sure and temperature rating of the installation. Joints and
more than 30 inches (762 mm) above grade at such edge, a connections shall be made in accordance with the applica-
ble provisions of Chapter 7 of the International Plumbing
level platform shall be provided on each side of the appli-
ance or equipment to which access is required for service, Code relative to the material type. Condensate waste and
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repair or maintenance. The platform shall be not less than drain line size shall be not less than / -inch internal diam-
30 inches (762 mm) in any dimension and shall be pro- eter and shall not decrease in size from the drain pan con-
vided with guards. The guards shall extend not less than nection to the place of condensate disposal. Where the
42 inches (1067 mm) above the platform, shall be con- drain pipes from more than one unit are manifolded
structed so as to prevent the passage of a 21-inch-diameter together for condensate drainage, the pipe or tubing shall
(533 mm) sphere and shall comply with the loading be sized in accordance with Table 307.2.2.
requirements for guards specified in the International TABLE 307.2.2
Building Code. Access shall not require walking on roofs CONDENSATE DRAIN SIZING
having a slope greater than four units vertical in 12 units EQUIPMENT CAPACITY MINIMUM CONDENSATE
horizontal (33-percent slope). Where access involves PIPE DIAMETER
obstructions greater than 30 inches (762 mm) in height, Up to 20 tons of refrigeration 3 / inch
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such obstructions shall be provided with ladders installed Over 20 tons to 40 tons of refrigeration 1 inch
in accordance with Section 306.5 or stairways installed in Over 40 tons to 90 tons of refrigeration 1 / inch
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accordance with the requirements specified in the Interna- Over 90 tons to 125 tons of refrigeration 1 / inch
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tional Building Code in the path of travel to and from 2
appliances, fans or equipment requiring service. Over 125 tons to 250 tons of refrigeration 2 inch
306.5.2 Electrical requirements. A receptacle outlet shall 1 inch = 25.4 mm, 1 ton = 3.517 kW.
be provided at or near the equipment location in accor- 307.2.3 Auxiliary and secondary drain systems. In addi-
dance with NFPA 70. tion to the requirements of Section 307.2.1, where damage
to any building components could occur as a result of
overflow from the equipment primary condensate removal
SECTION 307 system, one of the following auxiliary protection methods
CONDENSATE DISPOSAL shall be provided for each cooling coil or fuel-fired appli-

307.1 Fuel-burning appliances. Liquid combustion by-prod- ance that produces condensate:
ucts of condensing appliances shall be collected and dis- 1. An auxiliary drain pan with a separate drain shall be
charged to an approved plumbing fixture or disposal area in provided under the coils on which condensation will
accordance with the manufacturer’s installation instructions.
occur. The auxiliary pan drain shall discharge to a
Condensate piping shall be of approved corrosion-resistant conspicuous point of disposal to alert occupants in
material and shall not be smaller than the drain connection on the event of a stoppage of the primary drain. The pan
the appliance. Such piping shall maintain a minimum hori- 1
shall have a minimum depth of 1 / inches (38 mm),
zontal slope in the direction of discharge of not less than one- 2
shall be not less than 3 inches (76 mm) larger than
eighth unit vertical in 12 units horizontal (1-percent slope).
the unit, or the coil dimensions in width and length
307.2 Evaporators and cooling coils. Condensate drain sys- and shall be constructed of corrosion-resistant mate-
tems shall be provided for equipment and appliances contain- rial. Galvanized sheet steel pans shall have a mini-
ing evaporators or cooling coils. Condensate drain systems mum thickness of not less than 0.0236 inch (0.6010
shall be designed, constructed and installed in accordance mm) (No. 24 gage). Nonmetallic pans shall have a
with Sections 307.2.1 through 307.2.5. minimum thickness of not less than 0.0625 inch (1.6
Exception: Evaporators and cooling coils that are mm).
designed to operate in sensible cooling only and not sup- 2. A separate overflow drain line shall be connected to
port condensation shall not be required to meet the the drain pan provided with the equipment. Such
requirements of this section.
overflow drain shall discharge to a conspicuous
307.2.1 Condensate disposal. Condensate from all cool- point of disposal to alert occupants in the event of a
ing coils and evaporators shall be conveyed from the drain stoppage of the primary drain. The overflow drain
pan outlet to an approved place of disposal. Such piping line shall connect to the drain pan at a higher level
shall maintain a minimum horizontal slope in the direction than the primary drain connection.

2018 INTERNATIONAL MECHANICAL CODE  27
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