Most efficient A/C mode?

Use auto and recycle. Do use fresh when first getting in the car and it's hot inside, then switch to recycle once it's cooler inside the car than out. Set temperature as high as you feel comfortable. Accept that even gas only cars use more gas with the AC on. Enjoy.

 

Also if you get too hot inside your car, most likely so will your HV battery as the air vent for drawing in cooling air is beside the rear seatback. I don't know know what temperature the HV battery finds comfortable though.

 

Rather than an ideal 'mode', a few tips to increase efficiency:

A higher fan speed will make it feel cooler than it is, so that helps a bit.

If you're coasting down hill and the battery's full, adjust the air to 'max cold' temporarily to take advantage of the 'free' energy.

When you first start out, roll down all the windows to let the hot air blow out, then start the ac.

Side window visors let you leave a small gap for the heat to escape, without making it obvious you left the windows open. They'll keep out most of an unexpected shower, but the bugs will still find their way in.

 

Off.

That's the most efficient AC mode. It is not the most comfortable.

I don't use auto. Instead I will use temp control but manually set the blower on the 1st or 2nd setting when it is too warm or stop and go traffic requires AC. At higher blower settings the ICE tends to turn on at lights.

 

Here in middle Tennessee, "the bowl of humidity, South", it gets really hot.........I leave my ac on auto, set on 74 degrees. I know my mpg will suffer, but I won't as much.
I just let the computer do the controling.

 

SHAWN - OOUCH. it's 91 degrees here in hollywood today. come on..............

 

It's been a bit toasty here too. I have the home AC at 81 F. We've been in the 90's for the past seven straight days. Today was 96. I drove across the metro area today (interstate) at 91 F w/ 60% humidity. No AC, window cracked, 57 mpg for the round trip. It's no problem as long as the vehicle is moving. I run the AC for the kids though.

When I was in Texas I would do 5K runs at lunch with the sun beating down, mercury well over 100. Had to cut my pace back considerably though... We had one stretch of over 30 days that hit 100 F. After getting accustomed to 110 F days, I feel like a sissy complaining about high 90's.

 

102 for 3 days and I rolled the windows down. I have done this for 6 years with my Civic hybrids. When my wife is in the car the AC goes on.

 

Pussies!
I drove across the Nulabour Plain in my Prius, the temperature outside was a lovely 48 degrees celsius. (118.4 f)

 

HAHAHAHA.....wow. cheers to you all. for me, i dont want to feel like i've just finished a 5 set tennis match, so the air goes ON.

man, you guys are hardcore. isn't life too short not to enjoy our drive??

 

Question...

I've been assuming that you can crank up the fan and it uses less energy than cranking down the temperature. Anyone have any specifics on this or tradeoffs?

For example, is running at 78 degrees, but fan on it's highest setting, more efficient than running at 72 degrees with the fan on a low setting? I know there are a lot of variables, but does anyone have any data points?

 

No data points, but that seems to work.

 

How tough is that, driving in the car with the air conditioning blasting?

The hottest I've cycled in was 44 celsius. I sat in the air-conditioned restaurant at the top of the hill for an hour, drinking root beer and chewing on ice cubes, before half-coasting the last few km.

 

Re: Question...

I might add that when I first saw someone mention keeping the temp at 78 degrees, I thought they were really fanatical. But I've found that it actually does keep it comfortably cool. It would be uncomfortably hot in the house, but with the vents right in front of you -- even without the air blowing straight onto you -- it's a good temperature. Point the air straight onto you when you need more cooling.

 

I have the least MPG hit by, setting the fan and temperature to lowest setting, set air flow selection to face, point the two driver vents to blow on the driver and if your by yourself close the two passenger vents. If you start getting cold increase the temperature, I have also tested this by listening for the wine of the A/C compressor and this appears to make it run less.

 

Re: Question...

81 in the house is actually comfortable as long as the humidity is under 50%. The main problem is that some points in the home have a lot more heat gain and will hit 83 or 84 during peak sun with the setpoint at 81. That's why I had to turn the set point down from 82...

Running 78 F in the home is pretty low. The only time temps like this feel stuffy to me is when I'm getting a lot of radiative heating from windows, or more importantly when the indoor humidity is rising because the home is near the balance point and the AC has not run in 12+ hours.

Comfort in the car is influenced a lot by radiative heating through the windows. Direct sun with the car temp at 78 can be pretty uncomfortable...while a shaded passenger will have a different impression.

 

Yay, root beer, I can't get it here in the UK. :Cry: Although that's probably a good thing as I gave up soft drinks.

 

Shawn, it was 95 (that felt to be 97) here in Nashville yesterday and it's still June.
And the humidity is so bad, I've been in Hollywood in the summer and I know it gets hot, too, but setting auto AC on 74 has pretty much kept me fairly comfortable with the auto fan setting, also.

:drama: