Requirement for Condensate drainage

[Greg Subick]

Did a home today that has two HVAC systems that were installed in 2002. The one pictured is in a hallway closet, second floor. The EV coil drain line goes into a vent stack that terminates through the roof but also has an open end inside the closet. There is no secondary catch pan.

My questions are:
1. In a 2002 installation over a living area, should there not be a secondary drain pan beneath unit and shouldn't it have a drain to the exterior?
2. Condensate line from EV coils should not be drained into a vent stack, but a waste stack, correct?

The other unit has a pan but does not have a drain line to exterior (nor anywhere else that I can see) and the condensate drain line off the EV coils goes directly to a waste line. While this appears acceptable, shouldn't the secondary pan still be drained to exterior?

[Scott Patterson]

Did a home today that has two HVAC systems that were installed in 2002. The one pictured is in a hallway closet, second floor. The EV coil drain line goes into a vent stack that terminates through the roof but also has an open end inside the closet. There is no secondary catch pan.

My questions are:
1. In a 2002 installation over a living area, should there not be a secondary drain pan beneath unit and shouldn't it have a drain to the exterior?
2. Condensate line from EV coils should not be drained into a vent stack, but a waste stack, correct?

The other unit has a pan but does not have a drain line to exterior (nor anywhere else that I can see) and the condensate drain line off the EV coils goes directly to a waste line. While this appears acceptable, shouldn't the secondary pan still be drained to exterior?

If it is over a living area of the home that could be damaged by water overflow from the condensation, it needs to be in a pan.

The condensation line connection in the photo is wrong. You need to have an indirect connection with an air gap so that you can not get any cross contamination into the air supply.

If the pan can not be drained to the exterior a float switch should be installed.

[Barney Bienz]

Hey Greg, long time, no see.
In answer to your questions:
1. There should be a secondary pan under the unit if installed over a finished space; however, the exception (at least in Shelby Co. and around here) is if the unit draws return air thru the bottom. Unclear from your picture whether this is the case or not. Secondary pan must have a drain line to the outside except where this isn't possible and then a float switch would be acceptable.
2. You are technically correct about the drain, but code here will allow drain into either as long as it is first run thru an 18" trap (min. 1 1/2" diam). Shelby Co. also requires a 3/4" running trap at evap and an air gap between the 2 traps.
Hope this helps.

[Greg Subick]

Barney, yes it has been a long time.....and the kids are growing up way too fast, don't ya think!?!

Anyway, thanks for your reply. The air is being draen through the bottom (the filter is in the base of the unit) and the trap sequence fits what you have described, so it looks like this will fly as is.

Thanks for the replies guys!:D

Greg

[Scott Patterson]

Barney, yes it has been a long time.....and the kids are growing up way too fast, don't ya think!?!

Anyway, thanks for your reply. The air is being draen through the bottom (the filter is in the base of the unit) and the trap sequence fits what you have described, so it looks like this will fly as is.

Thanks for the replies guys!:D

Greg

You really don't want it connected directly to the vent. You want an indirect connection with a trap so that air from the sewer can not be sucked back into system. Think Legionnaires disease.

The in-line or running trap does not do very much. They dry out fairly quickly when the system is in the heating mode and not in the cooling mode. Once it is dry, it will allow air to be sucked back into the conditioned air and then into the living area.

[Jerry Peck]

The in-line or running trap ...


Is not even allowed.

[Barney Bienz]

Scott, I actually agree with you. I hope I was clear in my original reply to Greg that I was referring to code in Shelby County,Tn where we are. This would not apply to some of the surrounding jurisdictions. According to code officials here, the 18' deep seal trap is not supposed to dry out, thus preventing air from the sewer being pulled into the system. This also appears to be an upflow furnace w/coil on top which would have positve static pressure in the supply plenum/coil case. As for the running trap, to me it's just a drain stoppage waiting to happen. Been beating my head against this brick wall for years.