Condensate drain blowing cold air

[Brian E. Kelly]

Originally Posted by cbottger

I am not disputing that fact, it is as it should be trapped at the A-coil.



Are you saying this is the only time a trap is installed at the A-coil if it is connected to a lavatory. I hope not.

Lets look at another situation

upflow or downflow furnace installed in a hall closet the A-coil has a P-Ptrap on the condensate line at the coil the line then travels into a crawl space and connects hard piped into lets say the bathtub drain line after the tub P-trap.

What would you report or would you report anything.

After the trap report as wrong Charley.

[Charley L. Bottger]

After the trap report as wrong Charley.

Thank you finally someone is seeing the big pic

[jlybolt]

Deleted

[Robert J. OConnor]

The original picture posted has the condensate service/vent stub incorrectly located before the condensate line trap. The correct location for the service/vent stub is after the condensate line trap as shown in the diagram Barry posted.

The purpose of the condensate line trap is not to prevent sewer gas from entering the building ... it is to seal the line so the system doesnt lose excessive pressure (yes, AC systems are pressurized). And the service/vent stub should not be capped, as that can result in condensate trap siphoning which would defeat the purpose of the trap.

The primary drain from the unit can discharge into the house septic system, but only before a septic system trap (again as per the diagrams Barry posted). That is what prevents sewer gas from coming out of the service/vent stub ... not the condensate line trap.

I also sometimes see attic AC systems with the stub before the trap (similar to the original post picture) and the condensate line tapped into the main septic vent in the attic. I guess the installers also thought the trap was to prevent the escape of sewer gasses ... ... gets written up as a defect every time ...

Also ... The secondary condensate pan can have either a drain to a visible location (no trap required) ... or there can be a stut-off float switch in the pan with no secondary drain line.

JMO

[Charley L. Bottger]

I also sometimes see attic AC systems with the stub before the trap (similar to the original post picture) and the condensate line tapped into the main septic vent in the attic. I guess the installers also thought the trap was to prevent the escape of sewer gasses ... ... gets written up as a defect every time ...

Hi Robert where you been hiding missed you.

That is the point I have been trying to make to many Hi's just check for a trap at the coil for the primary drain or the lack of and do not check where it is being discharged to. Many times I find them connected to a stack vent or in a crawl space after a building trap. I also write up every one.

[Robert J. OConnor]

Hi Charley ... just been working and lurking. There are a few good HVAC guys on here, but I still check in on the HVAC section occasionally.

In addition to checking for the presence of a condensate line trap and acceptable discharge point, it should also be checked that there is a service/vent stub and that it is downstream of the condensate line trap. The condensate trap is essentially useless if you put the service/vent stub upstream of the trap, as in the original post/pictures.

JMO