Air Conditioning

orr4hoos · 04-02-2005, 07:04 PM

I'm seriously considering buying a Prius, but as I live in the South (N.C.), air conditioning is a must. Can anyone give me some help with the following Prius a/c questions:

1. When you come to a complete stop and the gas engine is not running, does the a/c run? If so, does it use battery power? If is uses battery power, does the a/c run just as well (e.g. cool) as when the gas engine is running?

2. What experience have you had with mileage when the a/c is running? Does a/c significantly impact mpg on a Prius?

thanks,

Todd

**Tideland Prius** · 04-02-2005, 07:11 PM

1) Yes. It has the world's first Electric Inverter which allows the A/C to provide cold air when the engine is off.

2) I haven't seen significant mileage but then again my A/C use varies greatly so I can't compare.

DanP · 04-02-2005, 07:52 PM

<div class='quotetop'>QUOTE(orr4hoos\";p=\"77940)</div>

Quote:

I'm seriously considering buying a Prius, but as I live in the South (N.C.), air conditioning is a must. Can anyone give me some help with the following Prius a/c questions:

1. When you come to a complete stop and the gas engine is not running, does the a/c run? If so, does it use battery power? If is uses battery power, does the a/c run just as well (e.g. cool) as when the gas engine is running?

2. What experience have you had with mileage when the a/c is running? Does a/c significantly impact mpg on a Prius?

thanks,

Todd[/b]

The AC is wholly electric and does not directly depend on the gas engine at any time. I have found that it works just as well as the AC on my other cars (Camry and Windstar). As for the AC's effect on fuel use, it's bound to cause some reduction since the gas engine will have to run more to keep the batts charged. My batt level regularly dips below 5 bars (out of 10 on the display) when using AC, while it rarely dips below 7 when not using AC. I've only started using the AC regularly over the past week or so, and I have noticed a bit of a decline in fuel economy. For the first 150 miles on the current tank I did not use AC and averaged about 47 mpg (according to the computer). For the past 70 miles or so I've been using the AC a lot, and my average mpg is down to about 45. I can't say that my driving pattern has changed significantly in the past 70 miles, so I would attribute most or all of the change to the use of AC.

jeromep · 04-03-2005, 01:39 AM

The Prius a/c works great. Auto climate is a nice touch and a rare feature in vehicles of the Prius price point. Show me a Corola or a Focus with auto climate.

The Prius a/c is also very efficient. It uses a variable speed compressor which means that the system runs the A/C compressor at the speed necessary to acomplish whatever goal is set for the climate control system. a/c in cars today is run off from the pullys on the engine. The Prius design is such that there is no engine drag or pull down that you feel from some vehicle a/c systems, especially on smaller vehicles. Plus most vehicle a/c systems don't cool as well, while idiling or at a stop. The Prius system is consistant whether at speed or at rest.

Sure there will be a fuel economy hit, but I don't think it is nearly as much as on a conventional vehicle. And there is certainly a performance boost by having the a/c not dependant on engine speed.

KTPhil · 04-03-2005, 01:08 PM

"there will be a fuel economy hit, but I don't think it is nearly as much as on a conventional vehicle."

I would like to see numbers on this. Considering the inefficienciues of conversion from kinetic to electrical and back (vs. direct drive of the compressor from the conventional ICE), the net effect may be positive or negative.

KMO · 04-03-2005, 01:27 PM

This presentation specifically claims a 19% reduction in fuel consumption over the belt-driven air-conditioning system in the old Prius.

TucsonPrius · 04-03-2005, 01:37 PM

Here we use the A/C in the car pretty much year round. And yes, you do get a hit in MPG, but it's not too great. During our 100+ days (May, June, July, August, part of September, and sometimes early October), I see a drop of 3-4 MPG.

Thanks,
Shawn

Tempus · 04-03-2005, 05:17 PM

There are numbers posted here. I've posted the engineering papers on the A/C a couple of times.

Bottom line is it's about 40% more efficient than conventional AC.

sk66 · 04-03-2005, 05:45 PM

get that back window tinted..big heat draw ...

bobc · 04-03-2005, 05:55 PM

Hijack:

sk66. Here's all my points for you being a Bronze sponsor of the site with only 7 posts under your belt!

Now, back to air conditioning:

04-02-2005, 07:04 PM	#1
orr4hoos Join Date: Apr 2005 Posts: 3 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Air Conditioning I'm seriously considering buying a Prius, but as I live in the South (N.C.), air conditioning is a must. Can anyone give me some help with the following Prius a/c questions: 1. When you come to a complete stop and the gas engine is not running, does the a/c run? If so, does it use battery power? If is uses battery power, does the a/c run just as well (e.g. cool) as when the gas engine is running? 2. What experience have you had with mileage when the a/c is running? Does a/c significantly impact mpg on a Prius? thanks, Todd

04-03-2005, 01:39 AM	#4
jeromep Join Date: Dec 2004 Location: Eastern Washington State Posts: 821 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Re: Air Conditioning The Prius a/c works great. Auto climate is a nice touch and a rare feature in vehicles of the Prius price point. Show me a Corola or a Focus with auto climate. The Prius a/c is also very efficient. It uses a variable speed compressor which means that the system runs the A/C compressor at the speed necessary to acomplish whatever goal is set for the climate control system. a/c in cars today is run off from the pullys on the engine. The Prius design is such that there is no engine drag or pull down that you feel from some vehicle a/c systems, especially on smaller vehicles. Plus most vehicle a/c systems don't cool as well, while idiling or at a stop. The Prius system is consistant whether at speed or at rest. Sure there will be a fuel economy hit, but I don't think it is nearly as much as on a conventional vehicle. And there is certainly a performance boost by having the a/c not dependant on engine speed. __________________ It has been said: Hybrid drivers come in 3 flavors, greenie, techie and cheapie. Pick any 2. 2005 Prius, Millenium Silver over gray, package 5 (AI)

04-03-2005, 05:55 PM	#10
bobc Senior Member Join Date: Jan 2005 Location: Durham, NH Posts: 360 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Re: Air Conditioning Hijack: sk66. Here's all my points for you being a Bronze sponsor of the site with only 7 posts under your belt! Now, back to air conditioning:

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04-02-2005, 07:11 PM	#2
Tideland Prius Super Moderator Join Date: Oct 2004 Location: Canada Posts: 13,909 My Car: 2005 Prius Package: B Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 11	1) Yes. It has the world's first Electric Inverter which allows the A/C to provide cold air when the engine is off. 2) I haven't seen significant mileage but then again my A/C use varies greatly so I can't compare.

04-03-2005, 01:08 PM	#5
KTPhil Senior Member Join Date: Jan 2005 Posts: 1,213 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	"there will be a fuel economy hit, but I don't think it is nearly as much as on a conventional vehicle." I would like to see numbers on this. Considering the inefficienciues of conversion from kinetic to electrical and back (vs. direct drive of the compressor from the conventional ICE), the net effect may be positive or negative.

04-03-2005, 01:27 PM	#6
KMO Senior Member Join Date: Apr 2004 Location: Cambridge, UK Posts: 911 My Car: 2005 Prius Package: T Spirit Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	This presentation specifically claims a 19% reduction in fuel consumption over the belt-driven air-conditioning system in the old Prius.

04-03-2005, 01:37 PM	#7
TucsonPrius Senior Member Join Date: Mar 2004 Location: Tucson, AZ Posts: 157 My Car: 2004 Prius Package: #7 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Here we use the A/C in the car pretty much year round. And yes, you do get a hit in MPG, but it's not too great. During our 100+ days (May, June, July, August, part of September, and sometimes early October), I see a drop of 3-4 MPG. Thanks, Shawn

04-03-2005, 05:17 PM	#8
Tempus Senior Member Join Date: Feb 2004 Location: Washington DC Posts: 1,693 My Car: 2004 Prius Package: #9 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	There are numbers posted here. I've posted the engineering papers on the A/C a couple of times. Bottom line is it's about 40% more efficient than conventional AC.

04-03-2005, 05:45 PM	#9
sk66 Join Date: Mar 2004 Location: Las Vegas Posts: 13 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	get that back window tinted..big heat draw ...