Is the Solar package worth the extra money?

Out of curiosity... can you use the solar fan while driving?

 

Unfortunately no. It shuts down as soon as you hit the start button.

 

Although I didn't get it, the solar fan unit is the ONE option I may regret not having. It gets around 98 to 109 on somes days during the summer here and the large front and rear windows let in a lot of sun.

 

I just bought a package IV and got the solar package. I was most interested in having the sunroof, which is mainly why I opted for this package. That said, a buddy who does have one swears by it. He says the inside of his car never gets to 130 degrees on the hottest of days...like his other car did. Granted, it still gets plenty warm inside the car on hot days, but freom everything I've read, it stays within about 5 degrees of whatever the outside temperature is...and that helps on the car's heat load, and cooling when you first start out (ie cools down quicker). I also have to believe that keeping the inside of the car cooler, as much as you can, helps on the longevity of most everything inside the car.

 

Ditto. Could have had the rear camera w/o the solar but with summer temps in North Carolina it's an easy choice -- though now I spend more time trying to figure out whether, according to time of day, it's better to park in shade or sun.

 

The biggest problem with the Solar Pkg is that Nav is required, too, jacking the price up to a cost prohibitive level for some people. The Solar Pkg isn't exactly cheap at $3830, but if you subtract what the lame-nice person Nav Pkg costs, it brings it down to a more manageable $1800 (Invoice = $1440).

I'm sure they'd sell a lot more of the Solar Pkg if you could order it separate from Nav. That's exactly what I would have done if I could have. But then, Toyota wouldn't make as much money, either.

 

Question - I didn't see a need for the solar fan, although its nice. Why not just crack two opposing windows (the front windows, or the rear windows) down about 3/4-1 inch? That allows the wind through the car, and allows the heat to exhaust out of the car as well. Its still warm when you get in of course, but its not enough to be a big bother, since you can justh roll all the windows down immediately afterwards. Works for me, at least when temps have reached into the low 90's over here. Have a White Prius with dark grey cloth interior.

 

I don't know where the thread went, but I posted a link to an article in Pediatric in Review where they discussed such things, and how hot the interior of a car can get in the Summer. One of the conclusions they mentioned was that "cracking the windows a bit" does NOT significantly lower the interior temperature of the car, which on 90 degree days can reach into the 130's in the interior of the car. This is especially true on the hotest of days, where the air is usually stagnant, anyway.

The thermodynamics of why, go something like this - The car heats up due to radiative heating from the sun. Some heat trapped inside the car escapes via convection...much like heat escapes from your hot coffee mug. However, the amount of heat that is removed by convection, say via cracked windows, is far less than the heat generated from radiative heating....and as a result, the temperature inside the car continues to rise until some quilibrium is established beteeen the heat being generated by the sun, and that removed throught the cracks in the windows, etc. Opening your windows more does remove more heat, but then increases your chance of someone breaking into your car, or water getting in during a T-storm.

Much like having an attic fan, which sucks heat out of your attic, and helps to reduce the overall heat load for your AC....the Prius solar cooling system draws in outside ambient air, and pushed out (via vents in the car) the hotter interior air. That is, the amount of heat that is removed by convection is much greater because air is moving in/out of the car's interior. The net result is the temperature of the interior of the car is nearly equal to the outside temperature. That, in turn, reduces cool down time when first driving off, and, reduces the thermal (cooling) load on the AC, which then reduces drain on the battery, and therefore, helps gas mileage (a bit). Ah, those clever folks from toyota? But not for everyone, for sure. For me...I wanted the sun roof. The solar cooling system was just a bonus.

 

Or, in short, the answer to the original question is, "Yes".

 

I understand the finding that cracking the windows will do little on a normal, non-forced air vented car. But what about cracking the windows in conjunction with the solar venting?

 

I suspect that will help cool the interior quicker and more efficiently. The reason why i suspect that is I've noticed when I run the cars fan at some speed, and then crack my sunroof, therefore creating more area for the air to escape, that it feels like the fan speed has been kicked up a notch (ie the velocity of the moving air "seeps" a bit faster, or at the very least, the volume of air being circulated is greater). I have no proof that this is what's happening, but that's what it seems to me. So, if the amount of air moving in/out of the cabin is incrreased, then it stands to reason that the temperature will come down to near ambient a bit quicker than with no window cracked. But it's not going to go below what the outside ambient temperature is. It just should make the system work more efficiently, and cool to the ambient quicker.

By the way, there's an approximate 10 minute delay after you turn off the car, before the solar cooling systemn begins to do it's job. In a way, that makes sense - If you've been running the AC while driving, and say have it set to 74 degrees. When you turn the car off, even if the outside temperature is 95, it's going to take about that length of time before the interior heats up to the point that the inside is hotter than the outside. There's no sense running the system if the inside air is at 85 degrees, and the outside air is at 95, for example. It would make no sense to pull hot air from the outside into a cooler cabin. I'm sure the Toyota engineers have determined what the average length of time it takes for the interior to heat up on very warm days, when the cabin is set around the mid-70's. Coincidentally, I'll bet that times is around 10 minutes to rise about 20 degrees. Clever Toyota engineers.

 

Proof is easy to get...
just drive your car on ventilation only... no fan... and then crack a window or the sunroof and the amount of air coming from the air vents dramatically increases...:cheer2:

 

For me in SoFla it is a no brainer over, lets say, the Prius V...
but worth the extra money is a personal issue...

I love it, but I would be hesitant to insist to my fellow forum members to go for it... because it is very pricey considering the package you need to get...

I can enjoy the sunroof in winter and the solar roof ventilation system in summer...

one big caveat: in a very hot but cloudy day the darn thing does NOT work!!!

 

It needs solar radition to generate the juice to run the system.

But that said, on cloudy days, even if hot outside, the solar radiation that can drive the interior of your car to well over 130 degrees, is, for the most part, absent. Ergo, with no radiative heating, you don't need the solar cooling system.

Think of it as parking your car under a tree on a hot day. It's still hot, but not even close to what it would be if you move the car out into the sun, where radiative heating cooks the interior of the car.