Air conditioning condensation drain line

[aweeks]

The inside part of our upstairs air conditioner (is that the air handler?) is in our attic. The air handler condensation drain runs into a reservoir and that reservoir is pumped about 50 feet across our attic then outside. The drain line just lies on the floor of the attic running across joists and lying in the insulation.

The system was installed before we owned the house and looks like it was installed by a 4th grader, but that's another story.

When we bought the house the drain line that runs across the floor of the attic was 3/8 inch copper. Almost every spring I've found water damage on our ceiling, gone up to the attic to investigate and found water squirting from a crack in this drain line every time the pump activates.

I would dutifully cut out the cracked part of the 3/8" copper line and solder in a new piece of copper. It would last until the next spring when I'd do the same ritual.

At first I thought the copper line was cracking because I was stepping on it while I was doing other stuff in the attic. However, I took the cracked piece of tubing to our local Ace Hardware stor to find a replacement and the helpful clerk suggested it was freezing.

Ah hah! That's exactly what was happening. The drain line still had water in it from the summer, it's in the attic, the temperature drops below freezing and the line splits. As a temporary fix, I replaced the copper tubing with clear vinyl tubing. Seems to have worked fine so far, but we haven't had winter yet.

The question is: What is the right material for this drain line? The nature of the install and layout of the attic prohibits setting up a decline over the whole length of the drain tubing, so the line cannot gravity drain and there will almost certainly be standing water left in this line come winter.

Thanks for your help.

 

[coffeesnob]

The inside part of our upstairs air conditioner (is that the air handler?) is in our attic. The air handler condensation drain runs into a reservoir and that reservoir is pumped about 50 feet across our attic then outside. The drain line just lies on the floor of the attic running across joists and lying in the insulation.

The system was installed before we owned the house and looks like it was installed by a 4th grader, but that's another story.

When we bought the house the drain line that runs across the floor of the attic was 3/8 inch copper. Almost every spring I've found water damage on our ceiling, gone up to the attic to investigate and found water squirting from a crack in this drain line every time the pump activates.

I would dutifully cut out the cracked part of the 3/8" copper line and solder in a new piece of copper. It would last until the next spring when I'd do the same ritual.

At first I thought the copper line was cracking because I was stepping on it while I was doing other stuff in the attic. However, I took the cracked piece of tubing to our local Ace Hardware stor to find a replacement and the helpful clerk suggested it was freezing.

Ah hah! That's exactly what was happening. The drain line still had water in it from the summer, it's in the attic, the temperature drops below freezing and the line splits. As a temporary fix, I replaced the copper tubing with clear vinyl tubing. Seems to have worked fine so far, but we haven't had winter yet.

The question is: What is the right material for this drain line? The nature of the install and layout of the attic prohibits setting up a decline over the whole length of the drain tubing, so the line cannot gravity drain and there will almost certainly be standing water left in this line come winter.

Thanks for your help.

can't you just disconnect the line on both ends and blow out the water then reattach next spring.

 

[Mr_David]

You can try insulating the line. plastic, vinyl, or rubber tube will be just as vulnerable to freezing splitting or cracking as copper. You could blow it out before winter comes.

 

[phishfood]

PEX would probably be the least susceptible to freeze damage. But I would still try to get as much water as possible out of the pipe in the late fall. If you have a shop vac you could use that to suck it out of the outlet.

 

[IFIXH20]

Kudos to the ace hardware clerk for the diagnosis. Do you run a humidifier (in the winter) that is attach your heating system ?

 

[aweeks]

Kudos to the ace hardware clerk for the diagnosis. Do you run a humidifier (in the winter) that is attach your heating system ?

No, no humidifier in the system.

I guess removing the water from the line is the obvious answer, not the answer I wanted, because it's such a pain to climb up there, disconnect it, blow it out, etc. Also, in our part of the country, we'll have a freeze, then need the AC again, then freeze again, so it's more than one trip up there a year.

Maybe it's time to re-engineer the drain so that water can't stay in the line.

On the other hand, I shouldn't complain too much about trips to the attic. Last time up there I found a 1950s vintage stamped steel fishing tackle box someone discarded half a century ago, so the house giveth back. I'm going to be the envy of everyone on the river with their cheesy plastic Bass Pro tackle boxes.

Thanks for all the answers. Very helpful.

 

[johnjh2o]

I would take phishfood's advice and use a shop vac on it. That way it can be done without going into the attic.