How Stout is the Prius in the Summer Heat

<div class='quotetop'>QUOTE(yyyiiikes @ May 12 2007, 05:38 AM) [snapback]440461[/snapback]</div>

As many have suggested ... a lighter car color helps, tinting is a must, and a windshield shade is also a must. However, the Prius A/C is more than enough for the S. Texas heat. You'll take about a 10% FE hit if you run it all the time, but that's a small price to pay to be comfortable when it's 100 outside. As many claim, running the A/C when at highway speeds is more fuel efficient than driving with the windows down. Slow driving is another matter, but use the A/C at your own discretion (based upon what you want to take/endure).

 

I live in South Florida, and test drove a Prius in Ft Myers. The car was scorching hot after being out on the lot all day, with no tint, no sunshade, and a dark color, but within a few minutes, the A/C had the temp down to a comfortable level. By the time we went around the block, it was cool inside the car.

 

<div class='quotetop'>QUOTE(McShemp @ May 14 2007, 10:39 AM) [snapback]441657[/snapback]</div>

Keep in mind that the traction battery and its electronics are cooled by cabin air (the vent to the right of the rear seats). If you are uncomfortably hot, they probably are also, meaning that they will work less efficiently. In other words *not* using the AC on a hot day could actually reduce fuel economy.

 

Since the Prius A/C compressor does not depend on engine RPM to run, I think it is actually better at cooling a very hot, slow moving car than a regular A/C. I've had to rev the engine on my little Ford Fiesta in the past to get it to cool quickly on very hot days. The Prius just revs up the compressor using the battery, regardless of engine RPM.

 

It'll do fine however you have to tint the windows or you will cook surface areas exposed to direct sunlight.

 

I live in the same valley as F8L, The San "F'ing Hot" Joaquin Valley or sometimes call the Central Valley, and last year we had 10 days in a row of 110+F days in a row. If you point the vents directly at you its quite comfortable almost immediately. However, the back seat passengers have to suffer a bit longer, say 4 blocks. It was so hot at times that I would leave the windows slightly cracked and not shut it down if I was only going to be a short while. Usually with a good charge the engine wouldn't start but thats the nice thing about the Prius, it the bat got to low it would automagically start, recharge and then shut itself off.
Nice thing about the newer models is that the Air conditioner compressor motor has it's own electric motor, ergo no loss of cool air at stops and the mileage only takes a small hit this way. I'm pretty sure thats how it works anyway, check the board plenty of knowledgeable people around.

Wildkow

 

We live in Scottsdale and find our Prius air conditioning is just fine. It might take a little while to cool the car if you've been parked in the sun. but otherwise no problems. My wife (the primary driver) reports her gas mileage improves in hot weather compared to our "cooler" winter. It was around 48+ in winter and now is up to 49.4. The car is garaged at night and usually parked in the shade during the day.

It's not as good as the air conditioner in my 1988 Olds Delta 88 I owned in Florida years ago. That would blow snow out of the vents on a hot summer's day! However, I suspect power from at least three of the eight cylinders was driving that big old GM AC compressor and was at least partly responsible for my 14 MPG.

Mike

 

I lived in El Paso (very dry heat) for 2 years and now Killeen, TX (humid heat similar to Austin). I have had no problems with the A/C. The wife manages to freeze me out of the car and still get about 50 mpg. I tend to be more frugal in my use of A/C and get around 57 mpg.

I also have ceramic tinting on my windows to reflect more heat back than normal tinting. It cost twice as much but I rarely need to use my A/C above the lowest setting.

 

I drove home in 91 degree weather today. No problem. Use a Priuschat heat shield in the front window, which is parked towards the sun at work at the end of the work day. I also cracked the windows 3/4 of a inch today. One finds that with the temperature control, one can run at a warmer temp, and the dryness of the AC output will keep you cool. I had the control set to 83 F today. Better than 58 mpg, even driving into a 25 mph head wind. Side-drafting works quite well.

Supposed to cool off tonight. Tied a record. Minneapolis was this warm yesterday. Yikes!

No shade used on the hatch, but needed to warm the car up from 50 in the morning anyway. In the morning the Sun shines into the hatch.

Airconditioning system uses a variable speed electric motor driven compressor. So, the motor only runs fast enough as required by the temperature setting requires. If you drive into a shaddow, the motor slows down. Drive back out in the sun and it speeds up. This is the most efficient A/C available in a car.

 

<div class='quotetop'>QUOTE(jonz @ May 13 2007, 11:53 AM) [snapback]441141[/snapback]</div>

You go to the film mfgr's web site and look up the specs for the film. For example:

http://www.huperoptikusa.com/products_ceramic.cfm

http://www.suntekfilms.com/specs_auto.htm

 

<div class='quotetop'>QUOTE(yyyiiikes @ May 13 2007, 10:08 PM) [snapback]441400[/snapback]</div>

Normally I would agree with you that a black car will absorb more heat than a red car. However, from experience a red car seems hotter. I do not know if a red car tends to absorb more of the infrared radiation due to the close proximitry in the spectrum.
I often wonder why arabs living in hot deserts wear either white or black garments. Perhaps it distinguishes the goodies from the baddies.

 

SE Florida here...and no probs or complaints with the A/C at all. It cools better than some far more expensive cars I've had. When the fan is on full it is a bit noisy though.