Air Conditioner compressor noise

What are you setting the temperature at? And have you got the system on Auto? Is it cooling well? ( just some thoughts)

I'd get in touch with the dealership first, take advantage of your warranty, see what they say.

 

I don't recall ever hearing mine run. Running all the time may be the variable speed function. Old technology types have to cycle on and off but the Prius can just lower the speed.

 

scroll compressors make quite a bit of noise on initial startup if the temperatures are hot... tend to quieten down after they have run a bit.. Home A/C systems using scroll type compressors can do the same....

 

Yep it's a common concern and perfectly normal. The a/c compressor is driven by the HV battery so doesn't require the engine to run to power it, though as it draws about 4kw it quickly runs the battery low causing the engine to fire up. Normally the a/c noise of a traditional car is masked by the engine and fans. The noise settles down as the car cools down inside. If it continues to buzz then might be worth checking the gas level.

 

has the noise gotten louder, or has it always been loud? a few people have had new units installed under warranty because of noise increase. i guess it can be a sign of impending doom.

 

I don't think I've ever heard our AC compressor. My hearing's not the greatest, and we're not using AC much... Also, I'm wondering if what you're hearing is in fact the fans just in back of the radiators.

 

Quite normal for your car and climate. It is an advanced variable capacity system that has a lot more in common with a commercial 3 phase system than most average automobiles. Rather than cycle on and off, it is more efficient to keep the compressor running, it is variable, and will make more noise when it is running at full speed.

All the normal things that you can do to help it applies.... park in shade if you can, open windows/doors to let the hot built up blast of heat escape, consider window tinting and sun shields for the front and possibly back window as it is sloped so much that it is almost a skylight.... you know, you live in Texas.

Your system will run a little more conservatively, and efficiently if you use Eco mode.... but I know that when I was driving in 50 Celsius temps that I wanted it to blast.... but give it a try, and not to worry, nothing is wrong with that loud humming, it will tone itself down as it comes closer to satisfying whatever you have set the interior limit to.

And don't be afraid to take it to the dealer and hear that it is normal.... you did them a favour when you purchased the car from them.

Roland

 

I agree with all of the above. Even our compressor is a little noisy, especially if it is running full speed. It is a variable speed unit, and makes more noise the harder it works. Depending on your settings of your climate control will affect the sound you are hearing.

I suggest you run your climate control to a setting of somewhere around 76. Also use the "Auto" setting. If you are too warm or too cold, adjust the temperature a couple of degrees warmer or cooler. Running the system on "Lo" will cause the compressor to run all of the time and at full speed. You will also notice that on very hot days when using "Auto Mode" the fan will run very fast and the compressor will be noisy. Once the temperature in the cabin begins to cool down, the noise will quiet down and the fan will slow down also.

If you feel that your compressor is excessively noisy, I suggest two things. First, visit your dealer and ask to test drive a similar Prius. If you find the sound is the same, then you should have a pretty good idea that everything is okay. But if you still feel your compressor is too noisy, at that point ask your service writer to have the system checked. Depending on when you purchased your Prius and the amount of miles on her, the work they do might be covered under warranty. Your service advisor can give you all the details on that aspect.

Enjoy your Prius. It is the best midsize five door hatchback and the most economical out there IMO.

Regards,
Ron (dorunron)

 

50C! We are finally experiencing 30C days and everyone is melting. But we're NOT complaining. If you EVER hear me complain about it being too hot, please, just slap me upside the head!
In Edmonton Alberta we must not complain about it being too hot!
So maybe my experience with the A/C system is not in your ballpark.

 

I don't think your compressor will ever be noisy. Not with the temps you folks have up there!

Regards,
Ron (dorunron)

PS If you think it is hot, try living in the desert like Las Vegas or Phoenix. Now that is hot! Or you could just come visit me and we can compare Prius stories and enjoy the Texas heat. We have two seasons here. Summer and Winter... Not really, but usually spring and fall are short lived. This year seems to have been a exception...

 

I also had the same concern, and notice it is loudest when I first turned on the A/C, and I do keep my setting at low. However, recently I have noticed a vibration in the steering wheel when the A/C is first turned on too. And the car is nut moving......anyone experence this in the C?

 

These two messages are right on target. This is one of the advantages of a hybrid or electric car with an electric AC compressor, it's more efficient that many ppl are used to & behaves differently from what is expected.

 

It was 33 around here yesterday inland, and what made it more uncomfortable was the humidity. Not as bad as Toronto where I grew up, or down Florida way in summer... geez I can remember taking a jog around 7am in Lauderdale and just sweating buckets. I like a/c

My experiences with high heats in this car was during a long summer road trip that included parts of California, Arizona and Nevada... with the obligatory exploration of Death Valley during a heat wave.

If the car broke down in some of those places I think we all would have died, but it handled it like a champ.

The fact that it is a 'dry heat' really does make a huge difference to your personal ability to tolerate it.

Roland

 

Might the noise be from the AC condenser / radiator fan running ? That runs any time the AC is on.

Also, the electric AC compressor in my 2010 Prius Does not turn totally off, it runs at different speeds to handle large or small cooling loads. The compressor is powered by a 3 phase electric motor. The Prius inverter must have a Variable frequency drive built in that runs the compressor only fast enough to meet the cooling needs for any temp or fan setting.

I was playing with the AC system this summer on a hot day while parked and sitting in the front passenger seat with the window open so I could hear the compressor. I also wondered if the compressor just cycled on / off like a conventional system, or was it variable speed because it is electric powered ? With the car in ready mode, I switched on the AC. The compressor ran at full speed until the AC evaporator cooled to near the low limit. The compressor started to step speed down in about 50 rpm steps (stepped down about 5 times to about 1/2 speed). As I either increased blower speed or increased the temp setting, the compressor would step up the operating speed until the evaporator temp again neared the low temp limit.
A very slick operating and efficient system IMO.

 

To add to what John just wrote above, in many instances the compressor will cycle on and off once the cabin reaches the preset temperature. What seems to make it do that easily is if it not real hot outside. Example 85 Ambient 76 A/C Auto Setting. I have seen this happen more than once on our Prius. I also seem to recall the Gen II did something like too in certain situations.

Ron

 

Thanks Ron, makes perfect sense. While my 2010 Prius AC compressor only went down to the low speed setting on that 85 degree July day, I can see where if the AC load was very low, it would need a way to totally stop the compressor to prevent over cooling the evaporator and clogging it with frost.

 

Patrick,

I have found my Prius has exceptional operation within an incredibly tight window of parameters. Move too far out of those, and you're cooked. My fuel economy drops in both winter and summer -- the a/c uses a lot of electricity and the heater requires a lot of engine running. Spring at fall, between 45-50 mph, dry, and overcast seems to be the proverbial "sweet spot".

 

The above is exactly what I too observe.

Ron (dorunron)