Air handler condensate trap: any reason to NOT have one?

[gamp945]

Is there any reason that a professional would NOT install a condensate trap on an air handler (not furnace)?

I had a professional installation of a heat pump, and the tech did not install a condensate trap on the drain line, like so:

My blower is on the supply side of the coils, so the condensate drain is indeed under negative pressure when the blower is on.

I think I should install a trap, but thought I'd ask all the smart guys here first

Any advice is appreciated.

 

[bonneyman]

Water will be produced when running in cooling. And that water needs somewhere to go. Either down the drain, or (eventually) overflow the condensate pan and leak into your unit and house. Mold, bad smells, destroyed drywall - all good reasons to have a proper drain.

The EZ Flow drain system is a good one. I have it on my system. Really liked the P-trap is clear PVC - so you can see when it's getting clogged. Why didn't they think of that earlier?

 

[Big Bad Dad]

Look at the installation /operating manual for the air handler. The professional installer should have left it on site for you. The manufacturer's instructions are what should be adhered to. If they call for a trap, then building code will require it. If they do not call for a trap, you are OK.

 

[BillK]

Water will be produced when running in cooling. And that water needs somewhere to go. Either down the drain, or (eventually) overflow the condensate pan and leak into your unit and house. Mold, bad smells, destroyed drywall - all good reasons to have a proper drain.

The EZ Flow drain system is a good one. I have it on my system. Really liked the P-trap is clear PVC - so you can see when it's getting clogged. Why didn't they think of that earlier?

I think he has a drain. He is asking about the "U" trap.

 

[Jeepster04]

No.

 

[bonneyman]

I think he has a drain. He is asking about the "U" trap.

10-4 I read it too fast. I see his question now.

With all the horror stories I've heard concerning water damage and condensate leaks I just put in EZ traps as a matter of course. They're just so convenient and easy to use.

 

[pcmeiners]

I would put a trap in. Less avenue for mice/bugs, less airflow due to different pressure from the exterior and interior

 

[PoorUB]

Is there any reason that a professional would NOT install a condensate trap on an air handler (not furnace)?

I had a professional installation of a heat pump, and the tech did not install a condensate trap on the drain line, like so:

My blower is on the supply side of the coils, so the condensate drain is indeed under negative pressure when the blower is on.

I think I should install a trap, but thought I'd ask all the smart guys here first

Any advice is appreciated.

A coil on the return side of the fan? You need a trap!
There is no harm putting in a trap on a A coil on either side of the fan. In my city a trap is required, period.

 

[justinjoyal]

If the coil is on the return side you need a trap.

 

[Junkman]

Traps are good, but you need to remember that they need to be cleaned occasionally. When I had my store and the air handler was on the roof, the traps would always clog and ruin the ceiling, even though I paid for a service contract. They would come every spring and check the belts, etc., but never clean the traps. After that first time, I would specifically tell the tech that the trap needed to be serviced. If he didn't do it, and the ceiling tile got ruined, I would call the company and tell them that they needed to send a service tech to clean the trap and also replace the ceiling tiles. That got their attention and they made sure that they were clear every year afterward.

 

[fitter30]

Condensate trap is only installed to over come the negative pressure produced by a draw through coil and has to deep enough to work. A trap on the supply side won't do a thing because there is no negative pressure just positive.

 

[PoorUB]

Condensate trap is only installed to over come the negative pressure produced by a draw through coil and has to deep enough to work. A trap on the supply side won't do a thing because there is no negative pressure just positive.

That is a pretty broad statement. I agree on the positive side of an AHU it will still drain, but there is potential to draw sewer gas up the drain line when the unit is off. In many areas traps are required for the A-coil regardless if on the return or supply side of the fan. There is no harm in putting in a trap. My city requires a trap.

 

[jlrut]

That is a pretty broad statement. I agree on the positive side of an AHU it will still drain, but there is potential to draw sewer gas up the drain line when the unit is off. In many areas traps are required for the A-coil regardless if on the return or supply side of the fan. There is no harm in putting in a trap. My city requires a trap.

Yeah, he is right though. The only other reason is to stop sewer smell from going into the hvac system. Otherwise it’s a point of failure for plugging up. I do not install traps, code and installation instructions call for it and local inspectors have never knocked me for it.

 

[fitter30]

That is a pretty broad statement. I agree on the positive side of an AHU it will still drain, but there is potential to draw sewer gas up the drain line when the unit is off. In many areas traps are required for the A-coil regardless if on the return or supply side of the fan. There is no harm in putting in a trap. My city requires a trap.

If you tie a condensate line directly into a drain line when the trap dries out if the unit is off or on heat ( takes only a few days) the trap dries out and you are correct sewer gas enters the air handler. The only way it works that would be legal is a y adapter between a sink and its trap.

 

[PoorUB]

If you tie a condensate line directly into a drain line when the trap dries out if the unit is off or on heat ( takes only a few days) the trap dries out and you are correct sewer gas enters the air handler. The only way it works that would be legal is a y adapter between a sink and its trap.

How often do you see a condensate line just laying over a floor drain it doesn't have to be plumbed in.
Also, that is the reason our inspection requires it. I'm not going to argue about it or when it can draw sewer gas. Just the reason some places require a trap.

 

[LS6 Tommy]

You need a trap by CODE, regardless of which side of the fan the coil is on. It has to be an indirect drain with an air break or gap, depending on the receptacle. You cannot "lay it on a floor drain" or tie it directly into a sanitary line.

 

[mike93lx]

You guys have condensate going to sewer lines? Mine drain outside and I have them plumbed to drop into a channel that takes them away from the house

 

[PoorUB]

You guys have condensate going to sewer lines? Mine drain outside and I have them plumbed to drop into a channel that takes them away from the house

That would work great in North Dakota!

Where else would you drain condensate in a part of the country that is well below freezing for months?

 

[mike93lx]

That would work great in North Dakota!

Where else would you drain condensate in a part of the country that is well below freezing for months?

Yeah, the condensate for my furnace in MA did drain to the septic, but the a/c drained to daylight since it only made condensate in the summer. Freezing up isnt an issue for that