Air conditioning noise

Has anyone else noticed a very loud hum when using your air conditioner? I am assuming it is the compressor running but it can easily be heard a good 5-10 feet from the car. It is coming from the far left side of the engine compartment when facing the car and even causes a slight but noticeable vibration in the car. It will start almost as soon as you turn on the A/C and then gets louder until it is just down right irritating. After 10-15 minutes of running then it will shut off, but starts right up again if you turn off the system.

This is my first prius and I am not sure if this is normal or not. I took it in and a couple techs listened to it, but of course it was much better behaved around them. They set up an appointment for one of the prius techs to look it over but admitted they had yet to work on any 2010s. I'm just worried that they will come back and say it is nothing and then down the road I'll end up with a bigger problem.

Thanks!

Is it fan noise?

It could be, but when you open the hood I can't see anything that looks like a fan running in that section of the engine compartment. I did notice that it will start off high pitched and then after a few minutes will drop down a bit, but it seems to go up and down while running.

It's the ionizer or something like that ... coming from the driver's side vent, correct?

I know it's hard to say without hearing it, but is your compressor loud enough to be heard over the gas engine and 10 feet from the car? My salesman, who sells tons of prius, listened to it and said he had never heard one make that loud a noise. I just want to make sure I'm not making a big deal over something that is normal.

Thanks!

Ours is real noisy as well. You can turn the A/C off and it goes away. Has kind of a metallic air plane sound.

Its definitely the compressor, mine makes the loud metallic buzzing noise too when the AC is on. Didn't realize how loud it was from the outside when its on full blast until earlier today.

The fan makes more of a "whooshing" sound.

Just thought I would give an update. They looked it over and did confirm that the A/C compressor is bad. He said that it would probably have worked fine, but just been louder than normal. They had to order a new one and it should be all fixed by the middle of next week.

My prius is making a noise (kinda like baseball cards in the spokes of a bicycle) over by the glove box... i am fearing the ac is going out and im out of warranty maybe its the filer?

Buzzing sound when the AC is ON.

I hear a loud buzzing sound when the AC is on. I have 8000 miles on my 2010 Prius III and didn't notice this until just recently. The dealer told me this is normal for all Prius and mine was actully not as loud as most others! This really bugs me and I plan to go to a different dealer and test drive one of their Prius to hear for myself....Do any of you hear this also?

Re: Buzzing sound when the AC is ON.

Yep, mine does it too.

Re: Buzzing sound when the AC is ON.

I've been using my AC heavily (this *is* Austin) and don't hear anything unusual. What do you mean by buzzing sound? Does it sound like something in the fan? I've had odd debris caught in the fan of many cars over the years. I doubt that is what you mean, but I'm having a hard time knowing exactly what you are referring to.

Re: Buzzing sound when the AC is ON.

The AC compressor motor on the Prius runs on a variable speed inverter. The buzzing you hear is probably the inverter modulating frequencies. It is probably going to be loudest when the AC and the fan are running at full speed.

Re: Buzzing sound when the AC is ON.

The Prius A/C compressor is run with an electric motor, instead of being attached by a belt the gas engine, to allow it to run whether or not the gas engine is running.

It does make a different noise than regular A/C compressors, and it is more noticeable when the gas engine is off.

Usually, A/C compressors are either on or off. The Prius electric A/C compressor is of variable speed, to gain efficiency. The more cooling you require, the louder the sound will be.

Conclusion: all is normal.

Re: Buzzing sound when the AC is ON.

Don't wish to be a naysayer by mine is almost silent - I get a buzzing noise at startup which I put down to hybrid startup - but in usual operation, no noises I can put down to the A/C.

Re: Buzzing sound when the AC is ON.

If you press the A/C remote (included on solar), you'll hear the buzzing. It's the A/C running without the ICE.

Re: Buzzing sound when the AC is ON.

The Pruis AC compressor is a scroll compressor (reference page AC-12 in the factory service manual) which is the most efficient compressor technology currently available.

Scroll compressors produce a characteristic buzzy noise at initial start up. They will quieten down after a bit of running...

Scroll compressor concept [ame="http://en.wikipedia.org/wiki/Scroll_compressor"]Scroll compressor - Wikipedia, the free encyclopedia[/ame]

So chalk it up as one of the technologies used to improve car's efficiency..

Re: Buzzing sound when the AC is ON.

Thanks all for the insight into Prius opperation. I just never noticed this w/ AC on before... but then again this is my first summer driving it in a Texas Summer.