Air Conditioning - small line is HOT!!!!

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View Full Version : small line is HOT!!!!

mrfranclemont86
08-22-07, 11:34 AM
I'm having a problem with my a/c. I checked the lines outside and the larger one is sweaty and cool to the touch, the other one is very hot to the touch. The repair guy added freon and told me evrything was alright but adding freon did not change anything. Why is the smaller line so hot?

Beachboy
08-22-07, 11:54 AM
Its normal for the liquid (small) line to be warm/hot to the touch. The hotter the ambient temperature outdoors, the hotter the line will be. You did not say what troubles you were having with your AC other than your observation that the small line was "hot".
timjimbob
08-22-07, 11:59 AM
Line should be warm. It's dependant on how much heat the outside unit is rejecting. Could be too little freon or dirty outside coils. Your ac guy should have done a calculation to determine subcooling- this will tell him if this pipe is too hot or normal.

mattison
08-22-07, 12:43 PM
If you haven't cleaned the outdoor coils it should be done. they may look clean but dirt will impact inside of it. Also if he added refrigerant and it did not need it the head pressure will also increase raising the temp of the liquid "small" line.
Jay11J
08-22-07, 02:26 PM
How old is the unit?

Older equipment had higher pressure/hotter line than the newer equipment. As Matt said, make sure the coil has been back flushed from the inside out.
tobor8man
08-30-07, 09:33 AM
What's the best way to clean outside coils?
mattison
08-30-07, 10:03 AM
The best way would be to power down the outside unit all together and remove the top "be very careful not to damage the fam motor wires". Then hose it from the inside out. It's also a good idea to get some coil cleaner from the hardware store and wet the coil down, spray it good with coil cleaner, wait a few minutes then hose it out good.
Jay11J
08-30-07, 01:13 PM
If you are not able to get the coil cleaner, Simple Green will work as well.. Just won't get the foaming action to "push" the dirt out of the coil.

I know we have them at my Home Depot store, it's in a blue can, and will be by the Window A/C stuff.
gremlin
09-01-07, 07:36 AM
What kind of moron adds freon to a system with a hot liquid line? It was drilled into my head from day one, you walk up to a system, clean the coil, inspect for leaks, then check the charge. The other day I walked up to a two ton system that someone had stuff 18 lbs of gas into. Adding gas is always the last resort, preferably after fixing the leak. I'd love to know what this guy's excuse was.
john125
09-02-07, 02:50 AM
When is it to warm in general? 100 degree day
Ed Imeduc
09-02-07, 11:49 AM
john125 To warm to do what???? If you just let the unit set off for a short time. Then you can hose out the outdoor coil. Around here we run into a lot of units that hit high head. That is just from the pollen from the trees in the coils. A hose down and the PSI is back to where it should be
john125
09-02-07, 03:24 PM
The liquid line temp? To properly cool a house when its 100 outside.
ecman51`
09-03-07, 01:44 PM
100 in the shade most likely? Isn't it most effiecient for the unit's ability to cool, if the outdoor unit is in the shade and maybe where some breeze can get to it? And does't high outdoor humidity also lessen the ability for good heat transfer?
john125
09-03-07, 06:18 PM
Its beside the unit in full sun. My units subcooling is 7. The line temp was 124 with outside temp at 95 to 100. The compressor is kicking off at day(probably around 90). Its shaded at 6pm. 3am is when it feels like it is working.