2 condensate lines into sanitary drain - best practice

[Hamberg]

Doing a rehab with new HVAC (attic space) and tankless WH.

We have an HVAC (3/4") and WH (1/2") condensate lines we need to exit into a 1-1/2" line (already) plumbed into the utility room. (the house is slab on grade)

What are the requirements (if any), other than a trap attached to the 1-1/2" sanitary line? Sketch attached...

 

[Geofd]

2" stand pipe is better traped and vented

 

[Mitchell-DIY-Guy]

Around these parts it’s common to have the condensation lines (from equipment in attic) plumbed with an air gap to drip right into the standpipe used for the washing machine.

 

[MicEd69]

Don't forget to include at least a 2" trap for the HVAC drain line at the air handler.

 

[Twowaxhack]

Doing a rehab with new HVAC (attic space) and tankless WH.

We have an HVAC (3/4") and WH (1/2") condensate lines we need to exit into a 1-1/2" line (already) plumbed into the utility room. (the house is slab on grade)

What are the requirements (if any), other than a trap attached to the 1-1/2" sanitary line? Sketch attached...

City sewer or septic ?

 

[Hamberg]

City sewer or septic ?

City…

 

[Hamberg]

Around these parts it’s common to have the condensation lines (from equipment in attic) plumbed with an air gap to drip right into the standpipe used for the washing machine.

Hey @Mitchell-DIY-Guy - the hvac and WH are on the other side of the room and we specifically plumbed a line just for these two.

 

[Hamberg]

Am I over thinking this? Can I just use a floor drain and dump both directly into it?

 

[MicEd69]

Am I over thinking this? Can I just use a floor drain and dump both directly into it?


View attachment 44779

Sure, that would work just fine.

 

[Hamberg]

Here is a pic of the utility room, before it was drywalled. You can see the (capped) standpipe connection at the lower left

 

[MicEd69]

Is that a one of the drain lines running down towards the stub out?

When you say "standpipe" is there a P-trap in the slab?

Basically, all you need is a P-trap between the sewer and an air gap between the drains and the standpipe. The two drain lines can be combined into one if it is easier.

 

[Hamberg]

Is that a one of the drain lines running down towards the stub out?

When you say "standpipe" is there a P-trap in the slab?

Basically, all you need is a P-trap between the sewer and an air gap between the drains and the standpipe. The two drain lines can be combined into one if it is easier.

Yes that is the hvac line, the WH’s line is not there (yet).

So we “could” bring the 1/2” WH line over, tee (or wye) it to the 3/4” HVAC and just drop one line into a floor drain?

 

[MicEd69]

Yes that is the hvac line, the WH’s line is not there (yet).

So we “could” bring the 1/2” WH line over, tee (or wye) it to the 3/4” HVAC and just drop one line into a floor drain?

Yes, but won't you have to break up the slab to install that floor drain?

And I would use a wye to combine the two lines.

 

[Hamberg]

Yes, but won't you have to break up the slab to install that floor drain?

And I would use a wye to combine the two lines.

Thought was to connect the floor drain right to the standpipe line in the wall.

 

[Hamberg]

Another option would be something similar to this... Thought the floor drain option looked better?!

 

[Twowaxhack]

Don’t combine the two drains, run the hvac and the tankless separate until they independently drain into the receptor. Understand the difference between air gap and air break.

 

[Hamberg]

Don’t combine the two drains, run the hvac and the tankless separate until they independently drain into the receptor. Understand the difference between air gap and air break.

(please) correct my thought process...

typically there (or there shouldn't be) will not be any obstructions coming from the condensate lines, so (my thought) is you can extend the line(s) into the receptacle (air break?).

If there were the potential for something (food, sludge) then there would need to be an "air gap" so the line(s) would need to sit above the receptacle.

Am I at least on the right track?

 

[breplum]

Air gap of 1” IS required. And believe me, we encounter AC and acidic condensate lines frequently that clog with slime sludge. There are commercial tablets on the market to inhibit slime.

 

[TomFOhio]

I would also run the line's seperately and then do like your picture with the trap. Almost like a prep sink drain setup.