Thread: condensate line and pan

Is it required to have a secondary condensate line and a galvanized pan with a drain line on a second floor or just in an attic? I would think that it should be required on second floor also because you have finished living space below.

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Originally Posted by Tom Rees

Is it required to have a secondary condensate line and a galvanized pan with a drain line on a second floor or just in an attic? I would think that it should be required on second floor also because you have finished living space below.

*It is* already required there too.

From the 2006 IRC. (underlining is mine)
- 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:
(then it the options available, 1., 2., 3., and 4.)

No where in there does it say "when installed in an attic" ... also includes units installed on the first floor.

Thanks Jerry, It's just that when you see things done improperly so often that you start to wonder if you are wrong. I see furnaces with evaporator coils on second floors all the time with only one condensate line and no condensate pan. It makes you wonder if these people even bother to read installation instructions or code requirements.

An auxillary drain pan is not required in ALL situations.

As Jerry posted underlining is Jerry's BOLD is mine.
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:
(then it the options available, 1., 2., 3., and 4.)

So if the unit has a secondary drain, which all that I have seen have provisions for a secondary drain, then a auxillary pan is not required as long as option 2 or 4 is provided.

Option 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.

Option 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.

So if you use option 2 or 4 a auxillary drain pan is not required.

Originally Posted by Wayne Carlisle

An axillary drain pan is not required in ALL situations.

As Jerry posted underlining is Jerry's BOLD is mine.
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:
(then it the options available, 1., 2., 3., and 4.)

So if the unit has a secondary drain, which all that I have seen have provisions for a secondary drain, then a auxiliary pan is not required as long as option 2 or 4 is provided.

Option 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.

Option 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.

So if you use option 2 or 4 a auxiliary drain pan is not required.

Wayne,

Correct, except that option 4, while allowed, will not stop the overflow of condensate which will not stop the damage to building components, which is what the entire section is predicated on doing - not allowing the overflow to damage the building components.

Now, if ... *IF* ... that section included a requirement for an anti-freeze shut off switch placed on the coil to shut the unit down before the coil reaches 34 degrees F, then I could grudgingly buy into that as there would never be (supposedly, anyway) an iced up coil, in which case there would be no ice to melt into water with no place to go other than ... overflowing and damaging the building components.

On the other hand, option 2 will allow for the run off of melting ice, as long as that secondary drain line does not clog up ... which it will if left to drain water for a long period of time when the occupant has no idea what water dripping from the line down past the window means, so, what should be required (but is not) is for option 2 to require a shut off switch such that when the primary condensate line backs up, the water overflowing into the secondary condensate line shuts the unit off, and, if the unit is also iced up, the secondary condensate line serves as a drain to allow for that water to run off without causing damage.

The above said, the codes are "minimum" requirements and not basic construction knowledge, nor good, better, or best construction practices.