Air conditioning in Prius

Not sure if it's true that other hybrids do not have this feature, but it is certainly true in the Prius that you don't need ICE to run AC.

 

Yes. The A/C pump is powered by the high voltage DC system - and it's a variable speed system, so it runs at the speed necessary, not the speed available as most systems driven off the engine do. This results in much higher efficiency.

The high voltage DC system does get its' energy from the engine eventually, but it can run for several minutes from the "traction battery" without the engine running, and the engine is never connected to the A/C pump mechanically.

 

Here is the manufacturers description of the compressor.

DENSO's electric compressor is driven by an integrated motor and is able to provide air conditioning even while the vehicle is stopped. As a result, in hybrid vehicles with engines that automatically shut down when the vehicles stop, the electric compressor provides a comfortable air-conditioned cab environment in addition to fuel efficiency.

The newly developed electric compressor combines a scroll compressor, a DC brushless motor, and an inverter for activating and controlling the motor. Because of its optimized scroll form, the compressor improves efficiency in compressing refrigerant and reduces energy loss, leading to higher performance. "

 

Let me add to this thread by saying that I live in Dallas, TX and have been very, very impressed with the ability of the A/C system to cool down the car, even in our hot Texas summers. My other many vehicles that I've owned since moving here in 1980 have never been able to accomplish it as efficiently as my Prius.

Tim

 

I'm in Adelaide, South Australia.

It was 100 Degrees Fahrenheit here today and my pregnant wife and I spent the day driving around town looking at child seats and change tables.

Stinking hot outside, very very pleasant inside.

A couple of times I went out to the car early to turn the a/c on - this doesn't start the ICE but does drain the battery. Combined with lots of stop-start driving the battery eventually got down to two bars. As a result the ICE would stay running to recharge the battery even when we stopped. This didn't cause the car any problems, and only lasted a few minutes.

And we're still averaging 4.5 l/100km (62.7 Imperial MPG, 52 US MPG)...

I understand that the Honda Civic drives it's a/c from the ICE but don't quote me on that.

 

Has passed the test for me in South Florida for the past two summers. However, expect to open the windows for a while and wait an extra few minutes if you park your Prius in the direct summer sun.

 

my Dad also lives in Texas in Mission which is about a touchdown throw from Mexico so A/C was a MAJOR issue in any car purchase decision. he says he has no issues with the Prius A/C in any way whatsoever.

very short trips are frequent with him and the A/C provides him nearly instant comfort. there is only a few seconds wait from car start to cool air, not the 1-2 minute delay frequently found in belt driven A/C systems

 

Let me add my .02-cents. Have freon license, and worked on many a conventional car a/c. Thought I knew my mess till I messed with a Prius a/c. As to original question, yes compressor totally electric. Only time ICE plays in this is when batteries get down to 2-bars, and then ICE recharges them.

I have an 04 and also 05 Prius. When I bought the 05, used, with 37k, noticed a/c not quite as cold as wife's 04. No big deal. I work on car a/c's, right? I also bought the complete CD shop manual Toyota gives to it's mechanics to work on these cars with. I was totally shocked at all the sensors sending information to the computer that, in turn, tells the compressor what to do. I had to literally take all I knew about conventional a/c's and throw it out the window. It basically boiled down to taking it to the mechanic to have him put in just the perfect amount of freon with the special oil for the electric compressor before my a/c put out that big blast of cold air in the hot parked car when getting off work in the summer. I love it now. But you simply cannot look at gages and do this. The amount that goes in is critical. An ounce or two too much or too little will throw off the whole system.

Any mechanic who has the shop manuals for this car can testify to the advanced technology Toyota put into it, from everything from the Smart Key to the Senergy Drive to the Air Conditioner, and on and on.

Just off the top of my head, that little round marble glass ball on dash up in corner of driver side is telling a/c computer if the sun is shinning in car or not. There is a "humidity" sensor in center console. The temperature sensor is in return air chamber, or something like that in dash. I think there was a total of 5-input sensors going to the a/c computer. If it is raining out, and not too hot or cold, in the automatic mode, the a/c will remove moisture form the car without making the people feel cold or hot. Same for defrost mode, looking at humidity levels, not temperature. Cool, huh?

 

Having electric drive and the motor inside the compressor means there is no shaft seal to fail and leak. This is the most common place for refrigerant loss in automotive air conditioning. When was the last time you had a fridge regased? Unfortunately there are still flexible hoses in the system, the second biggest source of slow leaks. Protect the condenser with some mesh and there is little to go too wrong.

 

I live in Pensacola, and my 04 Prius is black. No problems. This car has the best AC of any car I've owned in the 30 years I've been driving. Because the compressor can "do its own thing" and is not dependent upon ICE rpms, the system is at its best when other cars may be struggling. Next time you're caught in an Orlando traffic snarl, notice what happens. Though you may be inching along for some time (your ICE is mostly off; other cars are idling at low rpms) your AC will turn your Prius into a mini meat locker pretty much on demand.

Another nice feature of the system: unlike the AC in other "small engine" cars, the Prius design has none of the sag-and-surge behavior that results as an AC compressor clutches and declutches from a conventional small I-4. It's operation is almost imperceptible, except of course, for the nice blast of arctic air it provides.

It's a tad ironic that there are worries about hybrid AC, mostly resulting from the unacceptable (to me anyway) characteristic of earlier designs (in which they required the ICE to idle to make cold air). The current Prius design is vastly superior to that (and conventional designs too).

Don't worry -- you'll like it.

 

When I shopped several years ago, the Honda Accord "hybrid" (which no longer exists, BTW) had an electric AC compressor.

 

Well, I guess the ill-conceived Accord Hybrid did have that virtue -- not enough to keep it alive, though. That said, earlier Honda hybrids did not have electric compressors, and IIRC, the Prius-I did not either. The current system is far-and-away superior, and is, in my opinion, a necessity to make the hybrid viable in all markets. In my climate, sitting with the AC off in the summer, for any length of time, is not acceptable at all.

 

My a/c was not working on my trouble free 2005 prius,I took it into the dealer and told me I need an A/C inverter. The repair estimate is 5339.00. I will never buy another Prius.

 

There is no such part as an "A/C inverter"

 

LOL, you think repairs are cheaper on other modern cars? Pretty much any major repair on modern cars will cost $3k+ if you go to the dealer.

You may want to look at your options. The dealer is not the only one but will definitely be the most expensive.

Luscious Garage | Blog | 270k Mile Prius: Dead A/C Compressor

 

I believe he/she is talking about the regular inverter which affects the A/C compressor. I thought the same thing as you though.

 

How about, "I will never again visit this service department that tried to rip me off in such an outrageous way."

If the inverter cooling pump has gone out, A/C will not work. Did you get yours replaced for free yet under the recall?

If the inverter has gone out, the car will not work.

It may be the compressor, which is an expensive repair, but on the order of $1500, not $5339.