window unit question

[Cybrvanr]

Here's a question for those HVAC gurus out there

A neighbor gave me an old window unit that wasn't cooling really well to mess around with. Frequently, I have found many times that the only thing wrong with them is that the condenser coils get all clogged up with leaves and other trash. Cleaning them restores them to perfect working order.

This on however is showing the classic signs of low refrigerant I believe. The high-side line straight out of the compressor is plenty warm, but the condenser coil is not very warm after the first few turns. The end of the condenser coil goes into the much smaller liquid lines. At that point, it's still at ambient temp. Inside, the tiny liquid lines get a thin coating of ice on them just before they go into the larger evaporator coil. The first half of the evaporator coil line gets a thin coating of ice, but the evaporator coil doesn't really get cool.

Now, I always thought window units have hermatically sealed coolant loops, and cannot really leak refrigerant. Where could it have gone? If it did leak out, where could it be added. I don't see any service fittings on it anywhere. I am thinking there is a restriction in one of the lines maybe...that sounds more logical.

...what do you guys think? I just got this thing to experiment with, if I mess it up BFD...but I figure it's something to learn MVAC work with!

 

[tomturbomatic]

"Have hermetically sealed coolant loops and cannot really leak refrigerant" I have some magic beans I would be willing to sell you after you explain why any system cannot have imperfections, why a line that is not properly anchored cannot have a connection loosened by vibration or why, especially with aluminum coils, corrosion cannot set in and eat into them. Sealed systems do leak, more often than the owners of same would ever dream. Sometimes the refrigerant is contaminated and will eat the system from within. When the refrigerant leaves the system, it goes into the air since the pressure in the system is higher than the pressure outside. Sometimes you can find traces of the oil that lubricates the compressor on some area in the lines where it escaped with the refrigerant. Leaking refrigerant or its careless release is why there has been a big effort to reduce atmospheric levels of flurocarbons by changing to less reactive refrigerants.

 

[petek]

I don't believe they're as hermetically sealed as the Hellmans Mayonaisse jars left on the doorstep of Funk & Wagnalls containing the questions to which Carnac the Magnificent will divine the answers.