Air Handler Condensation Drainage


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Old 11-29-22, 07:05 PM
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Air Handler Condensation Drainage

Hello All,

The condensation drain from my Air Handler was blocked. After digging up the PVC 'periscope' protruding from the ground next to my Heat Pump, I discovered a vertical pipe rise of more than 18-inches. Following removal of this vertical pipe, the water flowed freely.

What I'd like to do, is let the water drain from the 18-inch depth down into the ground, rather than the uphill climb to the surface. I've thought of inserting a large diameter pipe or plastic container with drilled drainage holes, into the ground below the drain pipe level. But my previous experiences have resulted in the dirt
passing through the holes and filling the container which results in pipe blockage. Even when I fill the container with rocks. Does anyone have suggestions how I can accomplish this without the dirt falling down and blocking the water flow?

Thanks for taking the time to read my message.

Tom
 

Last edited by taneal1953; 11-29-22 at 07:09 PM. Reason: clarity
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Old 12-03-22, 05:18 PM
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You have two refrigerant lines. The larger one gets cold and the smaller one gets warm/hot.
I severely doubt there could be enough cold to freeze the condensate.
 
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Old 11-29-22, 07:15 PM
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Can't visualize what you have.
Can you post a picture or two of what you have there ..... How to insert pictures.
Typically the condensation line just dumps out on the ground.
 
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Old 11-30-22, 05:34 AM
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Sorry, I didn't take any photos, and I'm a long way from the house at the moment.

The condensation drain pipe is not functioning, i.e. no water is coming out, although the pan under the Air Handler is overflowing. The copper piping and the PVC drain line from the Air Handler to the Heat Pump pass through a large underground pipe. This large horizontal pipe is 18" below ground level. The PVC drain pipe exits the horizontal pipe and after several inches is attached (via a 90-deg coupler) to a vertical PVC pipe. This vertical pipe extends about 8-inches above ground level. A short horizontal piece is attached to it and a 90-deg coupler at the open end directs the water flow downward onto the ground.

To check the piping for blockage, I cut the horizontal PVC pipe where it exits the large pipe (which is 18-inches below ground level). As soon as I removed this snorkel- or hook-shaped piping, the drain water gushed out of the pipe. I confirmed there is no pipe blockage by pouring more water into the drain pipe at the Air Handler location. The drain water simply can't make that more than 18-inch climb required to drain the pipe onto the ground.

My preference at this time would be to set up a small underground drainage field 18-inches below ground level. This would assure adequate drainage. The problem is how to prevent the sides of the hole from collapsing, yet allow drainage. I've considered a large diameter pipe (or a plastic box) placed vertically into the hole. If I leave the bottom end of the pipe open to allow drainage, dirt will backfill the pipe and at best reduce drainage efficiency. If I cap off the bottom of the pipe and drill holes, dirt will fill the pipe through these drain holes. I've seen this happen where my sprinkler system manifold and various underground wiring pass upward through a plastic box at ground level. Filling the boxes with rocks slows the process, but eventually they boxes are filled with dirt.

Any suggestions will be greatly appreciated.

Tom

 

Last edited by taneal1953; 11-30-22 at 05:38 AM. Reason: clarity
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Old 11-30-22, 09:57 AM
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I have a vague vision but why is the condensation going underground with the refrigerant lines ?
It sounds like a large trap is being created and that will stop the water flow.
The condensate line should be as short as possible and a straight shot to daylight.
 
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Old 11-30-22, 11:09 AM
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I have no idea why they did it this way. The heavy underground pipe emerges from the rear side of the foundation slab so I have no access. The alternative would be to start at the Air Handler and route a new pipe. This would require opening a full height section of finished wall and penetration of the outside cinderblock wall. It will be less work to make the current drain pipe function...I hope.
 
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Old 11-30-22, 08:19 PM
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Can you see the refrigerant lines and drain line in the basement or crawlspace enter that pipe sleeve that goes thru the foundation ? (yellow circle)

The drain line shouldn't be underground. Your system is getting air bound.
Just allowing air in at a tee (blue line) above the drain line may allow the line to drain.
You've cut where the purple line is and now the water is filling the ditch.... correct.
 
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Old 12-01-22, 10:53 AM
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PJmax: Can you see the refrigerant lines and drain line in the basement or crawlspace enter that pipe sleeve that goes thru the foundation ? (yellow circle)
Tom: I'm in a Florida Townhouse with no basement. The Air handler is on the second floor at the top of the staircase. It is between two bedrooms on the right-hand side of the house as seen from the front. The Heat Pump is in the backyard at the centerline of the house.
The refrigerant lines and the PVC drain line both disappear into a finished wall a few inches to the *left* side of the Air Handler. The exterior wall is on the *right* side of the AH, so the refrigerant/drain line may go straight down an interior wall to the slab, or over to the exterior wall and then down. They both drop vertically about 9 feet into the slab (at an unknow location) and continue about 25 feet in a horizontal run. Neither is visible at any point. I can only approximate where they emerge from the slab because the piping extends another 12 feet through the backyard until it reaches the Heat Pump.

PJmax: Just allowing air in at a tee (blue line) above the drain line may allow the line to drain.
Tom: There is a capped tee in the Drain Line at the Air Handler (your blue line). Even with the cap off, there was virtually no drainage until I cut the vertical hook-shaped pipe off the horizontal drain line as depicted by your purple line. Once the pipe was cut, water exited the pipe in a solid stream at full pipe diameter.


I'm reluctant to start tearing walls apart, but the best route for the drain pipe *would* have been from the Air Handler to the interior side of the exterior cinder block wall, then down to the slab and exit through the exterior wall. HOA rules do not allow any exterior piping above ground level on the front or sides of the house, so this interior route is required.

Assuming the PVC drain line is now functioning adequately, how much of an issue is it, if I leave it running along with the refrigerant lines as it is now? Is relocating it worth all the required work?
 
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Old 12-03-22, 08:47 AM
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PVC Drain Line - Air Pump Refrigerant Lines

My Air Handler is on the second floor, so the Condensation Drain Line and the copper Refrigerant Lines do a 10' vertical drop and a 25' horizontal run to the Heat Pump. The Refrigerant Lines are lightly wrapped with insulation and the 3/4" PVC pipe is zip-tied to them. All three are inside a larger pipe for the run to the Heat Pump. At the end of the horizontal run the Drain Line goes vertical for 18" with a hook-shape at the end of the pipe for drainage onto the ground.

Due to this 18" vertical rise at the drain end, I imagine there is a considerable amount of water remaining in the pipe when the unit s not running. I'm in Florida, so freezing temperatures aren't an issue, but I'm wondering if proximity to the refrigerant lines could freeze or form ice crystals in the drain line.

Thanks for taking the time to read this message and any thoughts are appreciated.

Tom
 
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Old 12-03-22, 12:18 PM
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It's helpful to keep all posts on the same topic in one thread otherwise all the same questions that were already answered.... get asked again in the new thread.

If your condensate line was freezing next to the horizontal lines it wouldn't flow when the "snorkel" was cut open. I don't really know what you can do there now. You can leave the snorkel cut off so that the condensate discharges in the open ditch but that will allow water to run back into the sleeve keeping the underground lines in water. That's not good.

An alternate....
If your ground percs well...... dig the ditch a few feet longer. At the end dig a pit with rock for the water to drain into. You need to make sure that the water drains well or when it rains that pit will fill up. This video shows a similar setup.
 
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Old 12-03-22, 01:53 PM
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PJmax:If your condensate line was freezing next to the horizontal lines it wouldn't flow when the "snorkel" was cut open.
Tom: When I cut the "snorkel" off the water flowed freely - but the AC hadn't been run for several days, so there was no chance of the Refrigerant Lines causing ice blockage at that time. I haven't run the AC for any length of time since then, so I don't know if normal usage will produce a blockage or not. I hadn't actually thought of icing in the drain line until you mentioned the issue in your earlier reply.


My plan at the moment is to create a "dry well" for the drainage water at the location of the cut off horizontal pipe. Or, if opinions are that ice is expected to be an issue, I will put in a new drain line that exits at the side of the house at ground level. The new pipe will mount on the interior side of a concrete block wall and will require opening up and then repairing the drywall at that location.

Anyone think that ice will be an issue if I leave the drain pipe at its present location?
 
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Old 12-03-22, 08:01 PM
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Great!

Thanks for the help.
 
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Old 12-04-22, 07:24 AM
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New Question:

The insulation below the Air Handler that lines the chamber behind the intake air filter is falling apart and saturated with water. It was so bad I removed it. Can you make a recommendation as to what material I should use to replace this? How important is this stuff for system operation?

Thanks in advance,
 
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Old 12-04-22, 04:15 PM
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If the air handler is in a conditioned location.... it's not important to replace.

I use Scotch 77M spray contact adhesive and foil backed insulation.
You can use foam.
Thin pieces of Roxul would work.
In the link is a bubble wrap. That would work too.
air handler re-insulating video
 
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Old 12-04-22, 09:40 PM
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Sounds good -- thanks for the info!
 
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Old 12-05-22, 04:03 PM
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Air handler drains lines often clog creating problems. Sometimes is bugs, debris, etc..There are many types of traps. But if that water becomes ice in freezing weather cracking trap, may resulti n leaks

https://www.google.com/search?client=opera&q=3%2F4"+HVAC+Air-Trap&sourceid=opera&ie=UTF-8&oe=UTF-8

When DH 1967 AC handler refrigerant coil support legs rusted away, propped it up with spray foam.
https://www.grainger.com/product/2PE...B&gclsrc=aw.ds
Still good29 year later. Now worry bottom of handler cabinet will rust out.
 
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Old 12-08-22, 02:10 PM
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Thanks for the info "doughess."

My Carrier FX4DNF Air Handler does NOT have a P-Trap, and has had condensation overflow problems in the past. P-Traps have their own issues: clogging, slime, evaporation, etc. If I put a capped tube in the drain line prior to the trap, and monthly, pour enough vinegar into this line to completely flush out the trap I could avoid some of these woes. I'm already doing the monthly vinegar pour to clean the line so it wouldn't be any extra work.

As an alternative, what does anyone think of the various "waterless" traps?

PS, To install a Waterless Trap, the Air Handler's "Max Plenum Pressure" is required info. I just called Carrier and was informed they don't have any technical info, I need to call a service technician. Seriously?
 

Last edited by taneal1953; 12-08-22 at 03:02 PM.
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Old 12-09-22, 09:20 PM
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Yes, air handler drain line trap/devices have problems. But bugs and other things entering handler through drain can create even more.

To easily see trap status Installing on exterior line with clear plastic unions on either side make cleaning easy: https://www.supplyhouse.com/DiversiT...IaAtUbEALw_wcB
 
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Old 12-10-22, 02:00 AM
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Not sure Doug understands what the problems are that you are having due to your unique situation.
The condensate line rarely drains underground.

I would think your drain line requires air like I've illustrated with the addition of the blue pipe.
 
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Old 12-10-22, 08:37 AM
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Post the model number of your air handler.

Most air handlers require a trap to drain.
If the evaporator coil is before the blower it will be under negative pressure.
A P-trap will help the air handler drain properly.

If you manage to get rid of that oversized P-trap you will likely need to install a regular P-trap.





 
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Old 12-10-22, 02:31 PM
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taneal1953issue is condensation water drainage was blocked.

Blockage may arise from improper pipe sizes, pitch and material clogs I.e particles of insulation from handler or debris in drain lines I.e bugs, mold, etc. Various type of traps are installed to keep debris out of drain lines also get blocked.

Rarely is adequate venting an issue. Pjmax post#19 about adding separate pipe ,may facilitate venting, but does not eliminate blockages, and also may detract from solving problem, or help to understand it..

DH understands the issue. Was engineer for manufacture of specialized industrial AC systems with 1degee F and 1 % humidity control. Posts #16 & #18 explained the issues with trade-offs and ways to deal with blockage..

Houston204 post #20 is helpful with diagram to understand trap installation.
 

Last edited by doughess; 12-10-22 at 04:12 PM.
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Old 12-10-22, 02:43 PM
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Have you guys read post 6 ?
The condensate goes down thru the house..... thru the foundation and discharges 18" below ground.
 
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Old 12-10-22, 04:48 PM
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The condensate goes down thru the house..... thru the foundation and discharges 18" below ground.
Yes, water flows down hill when there is no dam or blockage.

Bugs and other things need water. Drain lines are two way streets.

When fixing a problem it is often an opportunity to avoid it in the future and make system more reliable, easy to maintain.

That is what some of these post are about. Do no assume permanent fix. Murphy's Law

Some do not assume they have found the ultimate permanent solution
 
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Old 12-10-22, 05:42 PM
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Long traps hold a lot of water and should be blown out annually. Pouring bleach into the drain at the cleanout that PJ drew in should also be done at least once a year.

The cleanout would need to be capped if it is a negative pressure application like most.

The termination should be reinstalled as it originally was so that it looks like PJ's picture.

With regular maintenance it should drain as shown in PJ's picture as long as the added cleanout is capped.

A condensate pump added at the air handler would help drain the unit if it fails to drain as shown in the drawing but it likely has run this way for years.

Adding a condensate pump might allow you to drain the unit into the plumbing instead of dumping it outside.

If an AC drain terminates outside in my area we are required to add a french drain at the drain termination. (Digging a hole and filling it with pee gravel). I would still terminate it in the air above the gravel with a 90 down.
 
 

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