Is it just too hot for the A/C to function?

parking in the shade ,

when its' 110 it just takes a long time to cool it down if it's been parked in the sun
using a wind screen and sometimes rear deck shade helps

for years i worked downtown, and gladly paid 40 bucks a month to park in a multi storied thick cement parking garage, by the time i got out to the street it was nice and comfortable in the cabin

 

At least on the v, and I think on the liftback, PHV, and c as well, Eco mode limits the A/C. If you are in Eco mode turn it off and see if the A/C does not ramp up. I use Eco mode 8 months a year, but not on summer afternoons.

 

Lots of Prius in Phoenix, and no real complaints from what I've seen. Parking in shade with windows cracked does make a huge difference. Parked in the sun, cabin temp can reach 180 degrees. It will take a while for any AC system to pump out that much heat, but within a minute or two the air coming out of the vents should feel cold even if the air in the cabin is still hot. If it doesn't feel cold right at the vent you might want to get your system checked. If it is cold but just takes time to cool the cabin, usually opening the windows part way and setting the system to fresh air and max cold should help speed up the process. Once its pushed the hot air out of the cabin and its down to about the same temp as outside close the windows and set the ac to recirculate. Pretty common procedure on most vehicles in Phoenix

Rob

Good call on checking eco mode, my Gen 2 doesn't do that and we haven't had our v through the summer yet.

 

The ECO mode defaults the A/C to recirculate function and eliminates outside air from mixing with the cabin air. It also lowers the fan speed slightly. In this mode the cabin air is constantly re-cooled to keep the A/C compressor from running excessively. I know that when I run my car in ECO mode with the A/C on it deals quite nicely with high outside temps. Right now it 100 degrees in my area and the A/C will darn near run you out. I attribute the cooling efficiency to the fact that I have highly reflective window tint installed. It makes a huge difference. I guess what I am saying is, "Get your windows tinted".

 

POINT -- Regarding: Window Tinting & Windshield Sun Screen = "...keeping the HEAT outside by not letting it get inside in the first place, as much as possible."

Just remember that solar energy accumulating inside a glass enclosure is *how* a green house "works."

 

To recap and simplify:

Be sure you are NOT in ECO mode when you need MAX AC.
Also be sure that you are not in RECIRC mode for the first few minutes.
If the outside air is 110, the air trapped inside likely is 150 or more.
If possible, drive with the windows down for a few minutes.......to help exhaust that super-heated air inside.

If none of that helps, you probably need your AC system serviced.

 

One tip I've heard, for A/C start up in a hot car:

Set the system on Auto, with A/C on, and raise the target temperature until the fan speed drops from full speed. As the A/C starts to become effective and fan speed drops, lower the target temperature, but never so much that fan speed reverts to full speed. Keep doing this until you get to a comfortable level.

 

For hot summers I use a heat shield and with window visors I can leave the windows open slightly. This helps reduce the super hot air. I start with the windows down and the AC set for 72. Once the cabin temp has cooled somewhat and the AC is blowing cold I close the windows. Auto AC will have the vents in recirc. Once on the highway it does not take long to cool the cabin and the AC fan starts throttling back. The quicker I get the cabin cooled the slower the increase in battery temps.

ECO will not cut it in a hot car. Once the cabin is cool you can go back to ECO. If the cabin is hot your batteries are hot.

 

i've heard that opening one door and quickly opening and closing the opposite door will remove excess heat before starting.

 

That's a myth, it's just not true. You get the most BTUs out of the highest fan speed. Doesn't always feel that way because the air coming out is warmer than if it were on a slower speed. But the cabin will cool down faster because of the greater volume of cool air.

All you're doing is distracting yourself while driving while limiting the efficiency of your air conditioner.

 

In the summer, I roll down all windows initially when entering the car to let the out the hot air. Even in 100 degree weather it helps reduce the heat load on the a/c system. I have my temp normally set at 74 degrees and for a few minutes it will blow out full blast in recirc mode. Some people think you should set the temp to it lowest setting but it won't cool off any faster in doing so. Once the temperature come down, 74 is just about right in maintaining a comfortably cool cabin.

 

How about putting in a manual mode with low speed fan? Sounds much simpler than your Auto workaround.

 

My wife always laughs at me because I open a door on each side and sometimes open the rear hatch for a minute. Getting the hot air out is my first priority. With the recirculate set it will keep cooling the cabin air. If you keep it on outside air, it will have to cool down the outside air. When air moves slower across the coils, the air is cooled down better. That is why in your house, the fan is set lower for AC and higher for heat. It gets hot here in Oklahoma too. 100 to 115 on a bad day.

 

What you are doing is reducing the A/C temperature differential by evacuating hot air from the interior. Anything you can do to reduce the differential will help the A/C do a better job of making the interior more comfortable. Using the recirculate mode, reducing radiant heat (thermal window tint)and shade are going to help. The air conditioner is only capable of aproximately 20 degrees of temperature differential. This means, if you introduce ambient outside air into a confined space at the same volume as the air conditioner the temperature will reduce by 20 degrees. The more you re-refrigerate the air in this confined space the cooler the interior temperature will get. When an A/C is working properly the registers will get to about 45 to 50 degrees F. However, the differential will not allow the interior to attain that temperature. So the the more you can keep the outside air and radiant heat out of the car, the better off you'll be in the hot weather. Phewwwww! What a rant!

 

Summary: Keep HOT outside, Keep COLD inside.

 

That is what I said but without all the good details

 

I couldn't take a picture. I opted for a 1000 words.

 

Your AC needs a recharge of coolant (maybe).

Also I leave my windows open at work (secure area). It stops the temp going over 100.


iPhone ?