When did the mechanical code first state this?

[John Goad]

When did the mechanical code first state this?
Section 310.0, 310.1 Condensate Disposal:
Condensate from air washers, air cooling coils, fuel-burning condensing appliances, the overflow from evaporative coolers and similar water supplied equipment or similar air conditioning equipment shall be collected and discharged to an approved plumbing fixture or disposal area.
If discharged into the drainage system equipment shall drain by means of an indirect waste pipe. The waste pipe shall have a slope of not less than 1/8 inch per foot (10.5 mm/m) or one percent slope and shall be of approved corrosion-resistant material not smaller than the outlet size as required in either Section 310.3 or 310.4 below for air-cooling coils or condensing fuel-burning appliances, respectively. Condensate or waste water shall not drain over a public way.

[Fred Weck]

The oldest one I have is the 1991 UMC, Section 510 (a), is word for word the same as 310.1 (except for the internal reference section numbers.

[John Goad]

Is it in any of the Mechanical editions of the IRC?

[Fred Weck]

It is not worded the same in the 2006 IRC
M1411.3 Condensate disposal. Condensate from all cooling
coils or evaporators shall be conveyed from the drain pan outlet
to an approved place of disposal. Condensate shall not discharge
into a street, alley or other areas where it would cause a
nuisance.
M1411.3.1 Auxiliary and secondary drain systems. In
addition to the requirements of Section M1411.3, a secondary
drain or auxiliary drain pan shall be required for each
cooling or evaporator coil where damage to any building
components will occur as a result of overflow from the
equipment drain pan or stoppage in the condensate drain
piping. Such piping shall maintain a minimum horizontal
slope in the direction of discharge of not less than 1/8 unit
vertical in 12 units horizontal (1-percent slope). Drain piping
shall be a minimum of 3/4-inch (19 mm) nominal pipe
size. One of the following methods shall be used:
1. An auxiliary drain pan with a separate drain shall be
installed under the coils on which condensation will
occur. The auxiliary pan drain shall discharge to a
conspicuous point of disposal to alert occupants in the
event of a stoppage of the primary drain. The pan shall
have a minimum depth of 1.5 inches (38 mm), shall
not be less than 3 inches (76 mm) larger than the unit
or the coil dimensions in width and length and shall be
constructed of corrosion-resistant material. Metallic
pans shall have a minimum thickness of not less than
0.0276-inch (0.7 mm) galvanized sheet metal. Nonmetallic
pans shall have a minimum thickness of not
less than 0.0625 inch (1.6 mm).
2. A separate overflow drain line shall be connected to
the drain pan provided with the equipment. This overflow
drain shall discharge to a conspicuous point of
disposal to alert occupants in the event of a stoppage
of the primary drain. The overflow drain line shall
connect to the drain pan at a higher level than the primary
drain connection.
3. An auxiliary drain pan without a separate drain line
shall be installed under the coils on which condensate
will occur. This pan shall be equipped with a water
level detection device conforming to UL 508 that will
shut off the equipment served prior to overflow of the
pan. The auxiliary drain pan shall be constructed in
accordance with Item 1 of this section.
4. A water level detection device conforming to UL 508
shall be provided that will shut off the equipment
served in the event that the primary drain is blocked.
The device shall be installed in the primary drain line,
the overflow drain line or the equipment-supplied
drain pan, located at a point higher than the primary
drain line connection and below the overflow rim of
such pan.

SECTION M1412
ABSORPTION COOLING EQUIPMENT
M1412.1 Approval of equipment. Absorption systems shall
be installed in accordance with the manufacturer’s installation
instructions.
M1412.2 Condensate disposal. Condensate from the cooling
coil shall be disposed of as provided in Section M1411.3.

G2427.9 (503.9) Condensation drainage. Provisions shall be
made to collect and dispose of condensate from venting systems
serving Category II and IV appliances and
noncategorized condensing appliances in accordance with
Section 503.8, Item 4. Where local experience indicates that
condensation is a problem, provision shall be made to drain off
and dispose of condensate from venting systems serving Category
I and III appliances in accordance with Section G2427.8,
Item 4.

G2427.8 (503.8) Venting system termination location. The
location of venting system terminations shall comply with the
following (see Appendix C):
4. Through-the-wall vents for Category II and IV appliances
and noncategorized condensing appliances shall
not terminate over public walkways or over an area
where condensate or vapor could create a nuisance or
hazard or could be detrimental to the operation of regulators,
relief valves, or other equipment. Where local expe-
rience indicates that condensate is a problem with
Category I and III appliances, this provision shall also
apply.