Johnson Controls GG9S'MP UIM-H-0712, Condensate Drain Termination, To Open Or Vented Drain

364861-UIM-H-0712

The furnace, evaporator coil, and humidifier drains may be combined and drained together. The evaporator coil drain may have an exter- nal, field-supplied trap prior to the furnace drain connection to prevent conditioned air leakage. All drain connections (furnace, evaporator coil, or humidifier) must be terminated into an open or vented drain as close to the respective equipment as possible. Regular maintenance is required on condensate drainage system.

Condensate must be disposed of properly. Follow local plumbing

or wastewater codes. The drain line must maintain a 1/4" per foot (20 mm/m) downward slope to the drain.

If an external vent tee is being installed, then it must have its own condensate trap before it is disposed into an open or vented drain.

This is not to be considered as a second trap as referenced else- where in this document.

Open Stand Pipe (Anti-siphon air vent)

5” Min.

Tee

To Open Or

Vented Drain

FIGURE 23: Typical. Condensate drain, vertical installation

The condensate will flow to the drain better if an open stand pipe is installed in the drain line. See Figure 23.

If evaporator coil or humidifier drains are combined with the furnace drain, then the open stand pipe could be raised higher, above the 5” minimum.

NOTICE

A loop has been added to the pressure switch vacuum hose. How- ever, ensure that all pressure switch hoses are routed such that they prevent any condensate from entering the pressure switch.

It is possible for condensation to form inside the combustion air (intake) pipe in the summer months if significant length of combustion air pipe passes through conditioned space. This problem can be averted by the addition of a simple drain tee, or a drain tee with a drain on the combustion air pipe as close to the furnace as possible, as shown in Figure 24. This is true for all long horizontal venting in any furnace configuration. This will prevent the condensate from entering the furnace.

Exhaust Pipe

Combustion Air Pipe

Tee with Drain Trap

Trap

Connect to Drain

FIGURE 24: Typical. Combustion Pipe Drain Tee

CONDENSATE DRAIN TERMINATION

A condensate sump pump MUST be used if required by local codes, or if no indoor floor drain is available. The condensate sump pump must be approved for use with acidic condensate.

DO NOT terminate the condensate drain in a chimney, or where the drain line may freeze. If the drain line will be exposed to temperatures below freezing, adequate measures must be taken to prevent the drain line from freezing. Failure to provide proper protection from freezing can result in improper operation or damage to the equipment and possible property damage. When exposed to temperatures below freezing, use of a 3 to 6 watt per foot at 115 VAC, 40°F (4.4°C) self-regulating, shielded and waterproof heat tape is recommended on the drain line outside the furnace.

DO NOT trap the drain line at any other location than at the conden- sate drain trap supplied with the furnace.

Liquid anti-freeze will cause damage to internal plastic parts of this furnace. DO NOT attempt to winterize the furnace using liquid anti-freeze.

Johnson Controls Unitary Products 17