Condensate from air washers, air-cooling coils, condensing appliances, and 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.
Where 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 (10.4 mm/m) or 1 percent slope and shall be of approved corrosion-resistant material not smaller than the outlet size in accordance with Section 310.3 or Section 310.4 for air-cooling coils or
condensing appliances, respectively. Condensate or wastewater
shall not drain over a public way.
Where approved by the
Authority Having Jurisdiction, condensate pumps shall
be installed in accordance with the manufacturer's installation
instructions. Pump discharge shall rise vertically to
a point where it is possible to connect to a gravity
condensate drain and discharged to an approved disposal
point. Each condensing unit shall be provided with a separate sump and interlocked with the equipment to
prevent the equipment from operating during a failure.
Separate pumps shall be permitted to connect to a single
gravity indirect waste where equipped with check valves
and approved by the Authority Having Jurisdiction.
Where an equipment or appliance is installed in a space where damage is capable of
resulting from condensate overflow, other than damage to
replaceable lay-in ceiling tiles, a drain line shall be provided
and shall be drained in accordance with Section 310.1. An
additional protection method for condensate overflow shall
be provided in accordance with one of the following:
- A water level detecting device that will shut off the equipment or appliance in the event the primary drain is blocked.
- An additional watertight pan of corrosion-resistant material, with a separate drain line, installed beneath the cooling coil, unit, or the appliance to catch the overflow condensate due to a clogged primary condensate drain.
- An additional drain line at a level that is higher than the primary drain line connection of the drain pan.
- An additional watertight pan of corrosion-resistant material with a water level detection device installed beneath the cooling coil, unit, or the appliance to catch the overflow condensate due to a clogged primary condensate drain and to shut off the equipment.
Where insulation
or appurtenances are installed where damage is capable
of resulting from a condensate drain pan overfill, such
installations shall occur above the rim of the drain pan
with supports. Where the supports are in contact with the
condensate waste, the supports shall be of approved
corrosion-resistant material.
Condensate waste pipes from air-cooling coils shall be sized
in accordance with the equipment capacity as specified in
Table 310.3. The material of the piping shall comply with the
pressure and temperature rating of the appliance or equipment,
and shall be approved for use with the liquid being
discharged.
For SI units: 1 ton of refrigeration = 3.52kW, 1 inch = 25 mm
The size of condensate waste pipes is for one unit or a combination of units, or as recommended by the manufacturer. The capacity of waste pipes assumes a 1⁄8 inch per foot (10.4 mm/m) or 1 percent slope, with the pipe running three-quarters full at the following pipe conditions:
For SI units: °C = (°F - 32)/1.8
Condensate drain sizing for other slopes or other conditions shall be approved by the Authority Having Jurisdiction.
| EQUIPMENT CAPACITY IN TONS OF REFRIGERATION |
MINIMUM CONDENSATE PIPE DIAMETER (inches) |
| Up to 20 | 3⁄4 |
| 21-40 | 1 |
| 41-90 | 11⁄4 |
| 91-125 | 11⁄2 |
| 126-250 | 2 |
The size of condensate waste pipes is for one unit or a combination of units, or as recommended by the manufacturer. The capacity of waste pipes assumes a 1⁄8 inch per foot (10.4 mm/m) or 1 percent slope, with the pipe running three-quarters full at the following pipe conditions:
| Outside Air - 20% | Room Air - 80% | ||
| DB | WB | DB | WB |
| 90°F | 73°F | 75°F | 62.5°F |
Condensate drain sizing for other slopes or other conditions shall be approved by the Authority Having Jurisdiction.
Condensate drain lines shall be
configured or provided with a cleanout to permit the
clearing of blockages and for maintenance without
requiring the drain line to be cut.
Condensate drain lines from individual condensing appliances shall be sized as required
by the manufacturer's instructions. Condensate drain lines
serving more than one appliance shall be approved by the
Authority Having Jurisdiction prior to installation.
Air-conditioning condensate waste
pipes shall connect indirectly, except where permitted in
Section 310.6, to the drainage system through an air gap or
airbreak to trapped and vented receptors, dry wells, leach pits,
or the tailpiece of plumbing fixtures. A condensate drain shall
be trapped in accordance with the appliance manufacturer's instruction or as approved.
Where the condensate waste from air-conditioning coils
discharges by direct connection to a lavatory tailpiece or to an
approved accessible inlet on a bathtub overflow, the connection
shall be located in the area controlled by the same person
controlling the air-conditioned space.
Female plastic screwed fittings shall
be used with plastic male fittings and plastic male threads.