How Stout is the Prius in the Summer Heat

Well I live in Northwest Ohio (15 minutes south of Toledo) where we have temperatures that range from -2 this winter to as high as 90-95 degrees in the peak of summer... the prius has an excellen Air conditioning system for both extremes... the ac will begin to cool within a minute... many of my passengers have been amazed at how quickly the AC blows out cold air... Grated Austin is a bit warmer then here, but I would feel more comfortable with the Prius AC than that of other cars...

 

The A/C unit is pretty fast and efficient. However the hit on fuel mileage depends on how long your daily commute is. On 90+ days, it take about 10 -15 minutes before the A/C brings down the temp to a comfortable level ( My Prius is Black). During this time you would definitely be taking a mileage hit. Once the temperature in the car stabilizes, the A/C compressor slows down and mileage jumps up to "normal" for the way I drive.

 

<div class='quotetop'>QUOTE(syclone @ May 12 2007, 06:29 AM) [snapback]440475[/snapback]</div>

I live in Dallas and I have been impressed with how cold the system is. When the system is first turned on it gives the impression that it's just not going to be able to keep up but within a minute it's very cold. Another priuschat member lives in Arizona and commented on how well his A/C does in the desert heat.

Hope that helps.

 

<div class='quotetop'>QUOTE(TimCarlos @ May 12 2007, 09:08 AM) [snapback]440529[/snapback]</div>

Also consider some heat shields for at least the front
windshield and rear hatchback window.

 

I agree that the number of acronyms here can be sort of ridiculous. It may be helpful to have this page open when you're starting to browse.

As far as the A/C, while we don't have anything like TX-level heat here in the northeast, I have been very impressed with the A/C performance so far.

 

well we're heading into our 3rd NC summer with a prius and we've had pretty decent experience with the car's performance. basically, as far as a/c goes it's fine. my last car didn't have functional a/c so i can't compare much, personally. but the battery likes about the same temp range that people like, so a/c use may take charge out of the battery (and therefore drop mpg) but it puts it in optimal operating temp range as well as keeping you comfy.

my prius is black with tinted windows (~30%), btw.

 

Since we are talking about battery care in the Sunbelt, I'll chime in.

I park under a tree at work with the windows cracked down slightly.

Hot temperatures is one factor that could threaten battery life, so driving out the hot air at the beginning of a trip could be justified.

I know of one Insight owner that runs a hose from his A/C to help cool the battery pack - I need that mod worse.

 

It does fine. It won't chill a six-pack held in front of one of the vents, like some cars can, but it keeps up fine in the desert southwest (Las Vegas, Phoenix, 115F) in the summer.

The biggest challenge is to cool the car quickly after it's been sitting in the sun for a while. Due to the large, sloped windshield, there is a lot of heat built up due to solar gain. A tight fitting sunshade and tinting your windows with a film with high heat rejection are a huge help - the car cools down much sooner when it's not allowed to build up to 150 plus degrees F inside. Without a sunshade, you might wish for a stronger A/C for those first few minutes after getting into a Prius that has baked in the sun for a few hours, but with one, you' won't think twice about the A/C.

 

Heat shields and tinted windows will help quite a bit.

Although I bought my Pri in February and therefore have not
really tested the a/c yet, I have found it to be extremely
efficient so far.

I have not had to lower the temp setting below 78 yet.

 

I live in the California Central Valley and it gets quite hot here in the summer (95-119deg) and I have not had any problems. On those extremely hot 110deg days the AC does take some time to cool the interior down but no different than any car. Invest in a good sun shade for the windshield and tint the windows like everyone else said. Lighter colored paint and interior help a bunch. A black car's paint can be 50deg hotter than that of a white car. We tested this on 8 different Camaros of the same model, on the same fender (metal) but with different colored paints.

 

<div class='quotetop'>QUOTE(priusenvy @ May 13 2007, 01:37 AM) [snapback]440945[/snapback]</div>

How do you find tint/film with a high heat rejection numbers? I personally don't trust the tinted window salesmen and would like to find out what I need without asking them. Yesterday was over 100 (our first day with the car) and the a/c was o.k. in front but weak in the back.

Jonz

 

Though I live in Los Angeles I spend a fair amount of time in Las Vegas. I am admittedly a big heat weenie and am very very very pleased with the A/C performance, particularly in the hot desert sun. Sure it takes a while to cool the car down, that's normal. However, it does not behave like other cars I've had - with the a/c nearly dying and literally heating up the car at stop lights, particularly the L-O-N-G Las Vegas stop lights, it continues to blow very cold when the car is sitting still.

For that reason alone it's the best a/c I've ever had.

 

Speaking from not too much experience... it's just starting to push 90 degrees here in Abq. Since I've been running my AC, my traction battery has been going purple (near minimum) a lot faster, especially after the car has been sitting a while. And it takes longer for the charge to go back up when I'm actually moving. After the initial engine warmup and cabin cooldown, it returns to just about normal with the exception of being stuck in stop-and-go driving or in line for 10 minutes at a driveup window. Then the traction battery goes purple (40%, as low as it goes) and the ICE (Internal Combustion Engine) kicks on more frequently to keep the battery from dropping too low, and ICE starts every time the car moves forward. When I go purple, my acceleration is slower too, I notice the difference from not having the elec motors assist as much. I expect a hit on mpg, but I'm not sure how much it will drop, I suspect maybe 4-5 mpg on my normal commute this summer. So I'll ONLY be getting 51 mpg.

I suspect that a good many of the highest hypermilers are in regions with moderate temperatures, not too low and not too high. Either that or they don't use their climate control and suffer a great deal. Since I started using the AC, I've been setting it at 78, that keeps it comfortable for me. When it starts getting into the high 90's... I'll have to wait and see.

 

Get yourself a white Prius. It wil absorb heat at a much lower rate than a dark colored car. Red seems to be the worst for heat absorbtion.

 

<div class='quotetop'>QUOTE(Orf @ May 13 2007, 09:07 PM) [snapback]441369[/snapback]</div>

Anyone know how much this is true and how much it's just a psychological thing? I thought that most of the heat absorption was because of the greenhouse effect inside the car. However, if the color of the car does significantly affect heat absorption, then black should be the worst.

This seems like something the Mythbusters should have tried. . .

EDIT: Indeed, the Mythbusters did try it. They found that a black car does get hotter, but only modestly. My next question would be if inside color or outside color is more important.

 

<div class='quotetop'>QUOTE(yyyiiikes @ May 13 2007, 09:08 PM) [snapback]441400[/snapback]</div>

You can get a heat shield through the PruisChat store. I highly recommend it. As far as AC, works great and once the car is cool you can manipulate the climate control to maintain a comfortable temperature while lessening any potential MPG decrease.

I opt ed for the light interior, cloth, simply because I have fried my legs on the leather, even wearing jeans, and dark interior should also absorb and retain heat longer than a light interior.

 

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

There's a fair bit of insulation between the skin of the car and the interior. Interior temperature is dominated by the Sunlight pouring through the windows at the rate of 1,400 Watts (1.9 horsepower) per square meter. Even the color of the interior fabric hardly matters; a dark interior will heat up faster but the final temp will be nearly the same. Five minutes versus ten minutes, more or less, hardly seems worth worrying about. In Dallas I bought the colors I liked (along with a Sunshade for the windshield).

 

Me and my maroon Prius live in Houston, which is at least at close to the sun as Austin (heh), and I have been VERY impressed with how quickly the AC cools the car down, and with a (so far) very minor hit on the mileage.