What you will learn from How to Fix Sweating Copper Pipes article:

  1. One of our readers submitted the question: How to Fix Sweating Copper Pipes - and we will answer her question
  2. A description of the problem with the sweating pipe
  3. The name of the copper pipe causing the problem and why it is sweating
  4. The repair of the sweating copper pipe to stop it from sweating
  5. What you need to know about sweating pipes and any moisture problem in your house
  6. Lots of resource and related links to help you learn

Fix Sweating Copper Pipes

How to Fix Sweating Copper PipesHow to Fix Sweating Copper Pipes - Richard, we have an air handler in a finished attic closet. We use the attic for our home office and TV room. I noticed the last time I went into the closet, the copper pipes that go into the air handler were sweating and dripping on the floor. It is a wooden floor, but I think if this continues, it will eventually ruin the floor and possibly the ceiling downstairs. What can I do to fix this problem of sweating pipes?

Does it mean there is a problem with our air conditioner? Will I have to call my HVAC service guy to fix this or is it something I can fix myself? We have used your site for many years to answer questions about our HVAC system. Thanks and I look forward to your reply. Joanna K. Hibernia FL

Fix Sweating Copper Pipes | Answer

Joanna, You are talking about the suction line that goes into the air handler. Somehow it lost its insulation and is sweating in the closet. The suction line typically operates below the dew point. When you have something that has a temperature less than the dew point temperature, then it will sweat. The moisture in the air is condensing, changing from a vapor to a liquid.

An excellent example of this is a glass of ice water sitting on the table. The temperature of the glass is so cold it is below the dew point temperature. A cold glass sweats and leaves a wet spot on the table. Thankfully someone invented coasters to protect the wood from cold drinks. Now, let’s fix those pipes to protect the floor in your closet.

Anyhow, Joanna, this is something you can fix yourself very quickly. Find your local hardware store and ask them for Rubatex pipe insulation. It’s black foam insulation. Additionally, please get the kind with a split on the side, the seam on the split has a type of adhesive with a protective plastic strip on it. You will trim the length of Rubatex needed to cover the bare copper pipe and then peel the protective plastic off of the adhesive strip after placing the insulation over the pipe.

Line the split up and make sure the adhesive glues the Rubatex split together. You want to create a vapor barrier to keep the humidity out and away from the pipe. That should fix your problem with the sweaty copper pipe.

Related Link: An Air Conditioner caused severe water damage (opens in a new window)

Water Dripping Pipes Cause 1
Wood to rot
Pipe Moisture Dripping Pipes Cause 2
Drywall to become waterlogged and eventually crumble
Wet Dripping Pipes Cause 3
Mold and mildew to grow inside your walls

Health and Prevention

How to Fix Sweating Copper Pipes

You must know a few things about this repair to your air conditioner lines:

  1. If the pipe has been leaking long enough, then it is possible that some of the moisture dripped down the pipe and went into the chase where the pipe runs. Sometimes, especially in new construction, the installer will use the void in the wall as his chase to run the pipes to the condenser. If that moisture got inside the walls, possibly created a problem with mold and mildew. Mold and mildew love dark, moist areas.
  2. It is vital that you only insulate the suction and not the liquid line. The suction line is the bigger of the two pipes that run to your condensing unit. Even the part of the suction line pipe that runs in the chase should be insulated with Rubatex and have a good vapor barrier quality of insulation on it; otherwise, you get the problem described above in number one. Never insulate the smaller pipe. It should never sweat. If it does sweat, that will defy physics.

Related Link: Another problem with an air conditioner and a leak (opens in a new window)

Central Air Conditioning Pipes Sweating or Leaking?

How to Fix Sweating Copper Pipes

Moist, humid air will get inside the pipe insulation, even a pinhole leak, and cause the pipe to sweat. That can lead to water damage because the moisture it creates will accumulate. It may appear that the copper pipe is leaking water. In the case of a central air conditioner or heat pump, the pipe itself does not carry water. It carries refrigerant inside. The water is coming from condensation from the cold pipe and the humid air. That happens on the outside of the pipe.

To rectify this, you or your family handyman need to insulate the pipe creating a vapor barrier around the pipe. Any cold water pipe or cold pipe that is below the dew point will sweat. That includes the suction lines on your central air conditioning system, which should be a copper pipe. Water damage can be severe and needs mitigation; otherwise, you run into other problems that can affect your health and the structure itself.

If you suspect mold or mildew in your walls, then you will have to call a professional to look into it. Most HVAC companies in Florida are well aware of these problems, as the humidity in Florida is something they have to deal with sometimes. At least the problems that come with high humidity and removing it from a conditioned space.

Related Link: Indoor Air Quality in your home or business (opens in a new window)

HVAC Cooling Repair - Conclusion

How to Fix Sweating Copper Pipes

Some companies specialize in water damage, and sometimes that includes dealing with the mold and mildew inside closed spaces. I know these companies use a special spray that kills the mold and mildew and prevents it from coming back anytime soon.

I know that some molds and mildews are not suitable for health, especially not breathing them every day. There are some people with severe allergies to mold and mildew, so make sure you protect yourself. In this case of the sweating pipe, the fix is easy. Or at least I hope it’s repaired easily. Good Luck, Joanna!!! I hope this helps!!

What Does Wikipedia say about Mold and Mildew Problems?

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How to Fix Sweating Copper Pipes | HVAC Cooling Repair