Liquid line is cold and sweating


  #1  
Old 06-06-10, 10:40 AM
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Liquid line is cold and sweating

I just had my evaporator coil replaced. After the guys got finished replacing it, I noticed that the liquid line is cold. It wasn't that way before they replaced the box coil. I'm concerned--it is dripping slightly at the lowest point in the line. The guy couldn't figure out what was causing the coldness in the line. He said that the pressure measured okay, and they he couldn't find anything blocking the line. Is this something I should be worried about?

Additional notes: The line is warmest near the condenser outside. It gets colder as it gets closer to the unit in my attic. The condensation on the line appears on the last 20 feet or so, getting worse the farther it gets from the condenser. The line is probably about 35 feet long.
 

Last edited by jimmarq; 06-06-10 at 10:59 AM.
  #2  
Old 06-06-10, 11:50 AM
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its not a heat pump is it? is it cooling? sounds like it should be heating your house. maybe u have a blockage in the condenser. that is very odd. or maybe the guy put the wrong kind of freon in your system, it most likely should be r22 system.
 
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Old 06-06-10, 12:20 PM
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it's cooling, but not as well

Before replacing the coil, a guy added freon and my house had no trouble staying at 75 degrees. Now, the house is struggling to stay below 78 degrees. So, it's definitely not cooling as well, but it is blowing cold air.

The guy said he didn't have to add any freon to the system. He said that if anything, the system was 1/2 pound heavy. I'm not sure what to think.
 
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Old 06-06-10, 07:05 PM
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Yes you should be worried.

Looks like a restriction to me, probably in the drier.
 
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Old 06-07-10, 11:50 AM
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The guy who did the work said he couldn't find the drier, so he installed one. From what I read about my unit (a Goodman), it already has one. So, I think I have 2 driers, now. Could that be causing the problem, too? Are 2 driers necessarily a bad thing?
 
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Old 06-07-10, 07:27 PM
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Originally Posted by jimmarq View Post
The guy who did the work said he couldn't find the drier, so he installed one. From what I read about my unit (a Goodman), it already has one. So, I think I have 2 driers, now. Could that be causing the problem, too? Are 2 driers necessarily a bad thing?
Yes, definite problem. You are correct about Goodman having an internal factory installed drier. If as I suspected in my earlier post that one is restricted it needs to be removed. You need someone who knows what they are doing.
 
  #7  
Old 06-08-10, 04:41 PM
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Thanks. The guy removed one of the filters, and that helped, but didn't fix the problem. It turns out that the new box coil came with a certain part (can't remember the name--restriction valve?) that had a bigger opening than the old one. The condenser needed a .083" opening, and the replacement box coil came with one that was .092". He replaced that part with one that was rated for my condenser, and everything worked fine. No more sweating. The house appears to be colling correctly, now.

Thanks everyone for your help.
 
  #8  
Old 06-09-10, 10:23 AM
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The piston has to be sized to what the condenser calls for

Originally Posted by jimmarq View Post
Thanks. The guy removed one of the filters, and that helped, but didn't fix the problem.

It turns out that the new box coil came with a certain part (can't remember the name--restriction valve? Piston flow-rater) that had a bigger opening than the old one.

The condenser needed a .083" opening, and the replacement box coil came with one that was .092".

He replaced that part with one that was rated for my condenser, and everything worked fine.

No more sweating. The house appears to be colling correctly, now.
Thanks everyone for your help.
The evaporator comes with a piston sized for its tonnage rating, which was probably higher than the condenser.

The piston has to always be sized to what the condenser calls for.

In the warmer environment, the oversized piston was dropping the liquid-line pressure enough that it was vaporizing a little.
 
 

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