House AC Coolant noises?

[Russ Filtz]

My AC runs from outside over a bedroom and into the inside unit. Whenever it's running I can hear what sounds like liquid gurgling/running through the pipes in the ceiling. Might be coming from the register in the ceiling though, hard to tell. Pretty loud and annoying in the bedroom though. Now the question, is this normal noise coming from the evaporator, or a sign the "freon" might be low or something?

[Al Willits]

The liquid line should be full of freon and fairly quiet, is charge gets low their may be gaps in the freon flow, this would give you a noise, also when the unit shuts down the boiling off of the freon in the liquid line may cause noise.

Be a simple matter to hook a set of gauges to the unit and check.

Units usually lose their cooling power as the freon level decreases.

Cure ii that's not it may be to wrap both lines in a insulated covering, might help the noise.

Al

[Russ Filtz]

Problem is this house is built with no attic access! High-ceilings and all. I'd have to rip down ceilings to get at any pipes I think.

[Jim O'Dell]

Unless you have access to either side and the insulation will slide down the pipe. But I'm guessing there is already some insulation on it to cut down sweating problems on the ceiling, so this probably won't be a viable possibility. Jim.

[Randy Denby]

Unit could be low on refrigerant...or it could be running high head pressure. Have you cleaned the "outside" condensor coils? Could also be a problem with the expansion valve....if it has one. Check the entering air temp at the return air grill, then the closest supply air temperature and compare the difference. Should be between 18-21 degrees.Use a good quality thermometer and try and stick it up inside the grill/diffuser for accuracy.
Might be a good time to have the unit serviced.