Moody new compressor.

[Psycho0124]

Well we recently replaced the 20+ year old 15,000BTU Amana window unit in our living room/den. The old compressor finally seized up after 2 decades of reliable and honorable service in the South Texas heat (the fan motor will live on to run my new cartridge tumbler ).

Anyway, the new unit is a slightly smaller Haier unit (I think it's a 13,000BTU) and, although it's been cooling wonderfully, I've noticed the compressor in the unit gets moody occasionally. First it starts humming slightly. The humming will slowly escelate into a buzzing and the vibration from the unit can be felt in the wall several feet away. After a while, the buzzing may decline until the compressor cannot be heard at all over the fan noise (the unit cools wonderfully through this whole cycle). The sound is not caused by the fan as changing fan speeds has no impact on the vibration or noise.

What could be causing this? Is the compressor in this unit defective somehow? There doesn't seem to be any correlation between the heat load on the unit and the strain sounds of the compressor. Running it in the evening is just as likely to get it humming loudly. I'm not too sure what to make of this unit..

[HayZee518]

the refrigeration charge is probably R-134a. It has a higher boiling point than R-12 or R-22. The charge also has a mineral oil that travels with the freon. when the unit starts a lot of the oil settles in the compressor then as the unit reaches operating pressures evens out. its purpose is to lubricate the rotating parts of the compressor and cools the windings. you say its cooling good - then - IF IT AIN'T BROKE, DON'T FIX IT!

[Psycho0124]

Yeah that was also my thinking. Let sleeping dogs lie. :P It's just worrisome when a compressor can go from perfectly silent to being heard 2 rooms away and nearly vibrating my window-panes out onto the floor. It's not just at startup either so I'm not sure what to make of it. Ahh I guess if it does die off this or next summer, I can use it for target practice. Is R-134a harmful to the atmosphere?

[HayZee518]

R=134a is a flourocarbon but it is less hazardous then R-22 and R-12 which also are hydrocarbons but R-134a doesn't harm the ozone layer. hey I got a cousin that lives in corpus christi! He used to live on Anderson Place but moved about a mile from there.

[Psycho0124]

Ahh nice! Yeah I'm over off Santa Fe. Older houses over here so I get plenty of chances to practice my handy-man skills. This old place was built to house officers and their families out on the air force base in the late 1930s. After WWII they sold it off and it was moved into the city as residential housing. I love the giant timbers they used to build this place. You could park a tank up on the roof and I doubt you'd even hear the place creak. Now I've got it wired for the 21st century with Cat-5 network ports in every room!

Hey I've been listening to the unit and when it's being quiet, it sounds like it struggles slightly for a few seconds every minute or so, then quiets back down. Sometimes the struggling gets louder and takes up to an hour to subside. If it turn it off for 10+ minutes and fire it back up, it continues struggling for a while. Could a contaminant in the system be clogging the orifice and working its way through as the pressure behind it rises?

Hey I really appreciate the help! I've found machines will usually tell you when there's a problem forming. When you don't quite speak (insert machine type) fluently, it's nice to be able to ask somebody that might!


P.S. I can't stand it any more.. What is that device in your avatar? At first I thought it was the generator on top of a hydro-electric turbine or something but from the wires, it looks too small for that. Some kind of beefy electric motor?

[HayZee518]

it IS a hydro generator. I work part time for a guy that owns a small two unit hydro station. That particular unit is an Allis-Chalmers hydro unit. Its output is only 375Kw max and the other unit is less than a megawatt. We operate at a 40 ft head in upstate NY.