Amazing climate control

<div class='quotetop'>QUOTE(KMO @ Jan 30 2007, 02:45 PM) [snapback]382844[/snapback]</div>

I believe the electric heaters only work on the front window defrost vents. This is to clear the windshield of fog so you can drive, before the heating system gets up to temperature.

It bothers me that the MFD doesn't display the actual cabin temperature, only what you set it at. The computer has to know the internal cabin temperature in order to control it. On the other hand, it was stated in another thread that because the computer also monitors the cabin humidity, it sets the cabin temperature to what "feels like" what you set it to, not to that temperature exactly. So if it showed the actual internal temperature, people would complain that it's not working properly.
I suppose someone could verify this assertion by bringing a thermometer into the car's cabin and seeing what the actual temperature is after the car has had time to get a stable temperature. However the only temperature the computer would be attempting to measure would be close to the internal temperature sensor, wherever that is.

 

I give a big thumbs up to the climate control in my Prius. I've had the vehicle almost two weeks, and I've not yet needed to access the Climate Screen.

 

<div class='quotetop'>QUOTE(seasalsa @ Jan 31 2007, 12:30 PM) [snapback]383472[/snapback]</div>

Well, I spent some time using the ACC and here's what generally happens.

Outside Temp: 65
Setpoint: 75

I get in the car and drive away. Heater fires up, pointing at my feet - first the fan is at 3, then after a few minutes it goes to 2. After about 10 minutes (including some freeway), it switches from my feet and starts blowing cold air into my face (fan still on 2). The air blowing on my face sure felt like is was cooled by the AC, but I guess it's possible it was the 65 degree outside air. The system went straight from blowing warm air on my feet to blowing cold air in my face.

So here's my problem, there's no middle ground. It's either heating or it's cooling. Why, once it reached it's 75 degree setpoint, did it not turn off (or at least the fan turn off or to it's lowest setting). It sure seems to me that it's wasting a whole bunch of gas to keep that cabin at EXACTLY 75 degrees. This is not acceptable and seems like a huge oversight on Toyota's part.

 

<div class='quotetop'>QUOTE(Leo @ Feb 1 2007, 01:25 AM) [snapback]383572[/snapback]</div>

That's wrong. There are 330W of electric heaters inside the heater core itself, so the heat is applied at the same point as the engine coolant. Then there is a 165W heater in each front footwell duct.

The front demister actually relies on the AC compressor - it uses dry air to clear it.

 

<div class='quotetop'>QUOTE(dgstan @ Feb 2 2007, 07:03 AM) [snapback]384284[/snapback]</div>

It doesn't sound to me like it's actually using the compressor there, it's just blowing the fan. The power for that is negligable. Don't you want fresh air in the cabin?

And to maintain temperature will always require a small amount of power. If you turned off for a while, you'd just need more power when you turned back on, as you'd have drifted further away from the desired temperature. I see no evidence that the system ever wastes power fighting with itself, as you seem to assume it does.

I think the main problem with the climate system is people trying to interfere with it because they don't understand it; I suspect that's why they left the internal temperature display off. It's always worked beautifully for me. My only two requests would be:

1) Economy mode - don't run the engine when stopped just to supply cabin heat; I believe some other HSD cars provide this now.

2) Allowing a temperature range - I'd be happy with 20C if it's freezing outside, and I'd be happy with 22C if it's baking outside.

 

My Pree has done well in the somewhat mild winter of Austin. (We had snow and ice this year though.) I want to see how well the auto air does in the hot Central TX summer.

My 1994 Grand Am blew cold air in Northern California where it was almost never needed in winter or summer. The A/C went out last spring. I put in a new system. It blew cold air again. I'm not sure what changed between 1994/2003 (besides two generations). When I say it blew cold air, it blew cold air in Austin.

I'm curious how well the Pree will perform. It's got to be better than a Honda or a Volvo. Those two are the pits as far as A/C! General Motors and Lexus have great A/C's. I will personally see. Any of you all have black Priuses with grey interiors in HOT climates? (Los Angeles and San Diego don't count!)