Amazing climate control

<div class='quotetop'>QUOTE(jmann @ Jan 28 2007, 04:51 PM) [snapback]382085[/snapback]</div>

I totally agree. It is great if you don't screw it up by trying to modify it to work like your last car. It is a state of the art system designed specifically for the prius.

See http://www.denso.co.jp/AR-e/1998/TW/climate.html

There have been several posts complaining about the lack of heat or cooling. It works great if you just set it and forget it.

Many fail to realize that the traction battery temperature is maintained by the inside temperature of the cabin. The more comfortable you keep the cabin the happier the hybrid car battery will be.

 

I remember reading the new features list and here's why I think the climate control system works so well: It isn't just a simple thermostat that turns the heat on or off depending on a single temperature sensor. Rather it takes lots of inputs: humidity, temperature in cabin, temperature outside, and sunlight level (via the round sensor on the dash). It then has a complicated fuzzy logic computer program that integrates all those inputs together to get the right temperature.

It knows that if the sun is really strong, then the sunlight striking the skin of the humans inside will make them warm even if the cabin temperature is perfect. So I think it lowers the cabin temperature so that the human feels like they are at the set temperature.

Similarly it knows that if the outside temperature is low then it will have to heat the air coming in more than it would if the outside temperature was warm. So it reacts quickly when you take your car out of a heated garage out into winter weather, or vice versa.

In other words the car is not just looking at what the actual cabin temperature is, but rather it looks at what are the factors that will make the occupant feel a particular temperature, so it can react before the cabin temperature changes uncomfortably.

It really works best when you set it and forget it.

 

<div class='quotetop'>QUOTE(tmorrowus @ Jan 28 2007, 09:03 PM) [snapback]382110[/snapback]</div>

It needs another sensor for my perimenopausal wife; I haven't seen a system yet that can cope with those hot flashes (picture us driving through the Northern Michigan snow, windows down, me freezing my a$$ off!)

Tom

 

<div class='quotetop'>QUOTE(Tideland Prius @ Jan 28 2007, 05:31 PM) [snapback]382097[/snapback]</div>

OOPS, Sorry. Here is a Quote from the old site that lists some of the features of the system.

Air-conditioning systems should not rob torque from hybrid powertrains on hot summer days. And they need to be able to heat interiors on cold days with little help from engine heat. For the Toyota Prius hybrid car, we developed an ultra efficient air-conditioning system that consumes minimal power.

Our new sub cool condenser and scroll compressor, equipped with oil separators, allow the air-conditioning system to run on 30% less power than conventional systems. And a two-layer flow heating, ventilating, air conditioning (HVAC) unit saves energy by re-circulating heat already in the cabin.

Air conditioners consume as much as 5% of engine output in passenger cars.
The climate-control system we created for the Toyota Prius consumes 30% less power than conventional systems of comparable performance. That improvement in energy efficiency is the result of advances in individual components and--equally important--improvements in overall system configuration.

Concern for the environment spurred automakers to create more efficient engines. But more-efficient engines mean less heat for warming vehicle interiors. Heating units have had to become even more efficient to compensate for lack of the waste heat that conventional systems use.

We have developed a system for the Prius that gets the same performance as conventional systems despite the lack of engine heat available for the system. Ventilation loss--heat that escapes from the cabin as fresh air comes in--accounts for 60% of the heating load placed on air-conditioning systems. Our two-layer flow air-conditioning system re-circulates warm air in the cabin to raise heating efficiency.

By using a 50/50 ratio of fresh and re-circulated air we were able to reduce the ventilation load 50%. At the same time, we were able to achieve the same cabin temperatures possible with conventional systems. Warm cabin air has a high moisture content. So, simply re-circulating the cabin air would fog up the windows. The new system sends re-circulated air out at foot level. Drier fresh air flows near the windows, which prevents moisture from condensing on the glass.

 

Just a quick question. A careful reading of how it works says that, for heating the interior cabin, an electric pump is used to circulate the hot water from the engine when the engine is not running.

I had read on other posts that the Prius had electric heaters to be used when the engine is not running.

Given that I have a 2006 model, which is it? electric heaters or electric pump? Electric heaters would use a lot of battery juice, whereas electric pump would use a nominal amount.

 

<div class='quotetop'>QUOTE(John in LB @ Jan 29 2007, 02:10 AM) [snapback]382209[/snapback]</div>

Both! The electric heating elements work at startup before the ICE is warm. After warm up when you stop at a light the electric pump ccntinues to circulate hot water while te ICE is off.

 

<div class='quotetop'>QUOTE(seasalsa @ Jan 29 2007, 05:40 AM) [snapback]382232[/snapback]</div>

So, given that I live in Southern California, I could unplug the electrical heaters - and improve the gas mileage slightly... Heating of the passenger cabin would occur at the same rate as other typical cars (that is as the engine warms up).

Does that sound right? or am I just wasting my time with a miniscule amount of power during the coldest of months? Your thoughts?

 

Well.... I don't know about anybody else here but it's been sub 20F here for the last two weeks and I find that my car can take 15-20 minutes to get warm. The electric heaters must be pretty tini I guess although I'm used to the old Volvo I used to have which would have super hot air pumping into my car within two blocks.....

 

The prius ICE runs very cool and it takes time for it to heat the cabin. One thing that really helps if you live in cold weather is to block the front grill so that less air cools the engine down. I did this a few weeks ago and it REALLY help with warming up the car. Maybe not as good as an old-tech volvo but still.

I used this link to understand how to block the front grill

 

The electric heaters are pretty mingy, as they run off the 12V circuit. You've got a total of 660W of electric heating power. Might sound like a lot, but it's nothing like as much as the main heater core, which has 5300W heating capacity.

Here, we don't get the electric heaters at all, or heated mirrors, or hot coolant storage. So stop whinging and appreciate what you've got!

 

The climate system is definitely cool, but not when somehow mold has gotten into it and now smells up the car when the air has been too warm and too moist for a while

No help toggling between outside/recirculate or cleaning out the filter. I'm at a loss and I dread turning on the A/C on a warm day.

 

<div class='quotetop'>QUOTE(Manksgloob @ Jan 30 2007, 12:48 PM) [snapback]382966[/snapback]</div>

A search on smell revealed the following. Maybe it will help

http://priuschat.com/index.php?showtopic=2...;hl=air+intakes

 

<div class='quotetop'>QUOTE(seasalsa @ Jan 30 2007, 01:03 PM) [snapback]382976[/snapback]</div>

Ah, thanks.
I wasn't so much stating my incompetence but rather just complaining.

But thanks for finding it for me, I'm looking into it now. Smell begone!

 

I don't know. I've had my Prius 2+ years and have never used the Climate Control. There's a couple of things I can't stand about them in general:

1. Why can't we set a temperature range? I'm fine if the cabin is anywhere between 68 and 78. My home thermostat allows my to set it up like this. If it drops below 68, turn on the heat. If it gets hotter than 78, turn on the AC. If it's between these two setpoints, please don't waste gas trying to change the cabin temperature.

2. When I get into my car that's been sitting in the sun and the cabin is 100 degrees, the auto-climate goes into ape-sh*t mode trying to get the cabin down to the setpoint. I can roll down the windows at first to get the hot air out and while this is happening I don't need the AC running full-blast. There should be some ECONOMY setting that understands you can't get a 100 degree cabin down to 78 in 5 seconds.

That said, I'm willing to give the thing another try. Here's my question: No matter what, when I engage the auto climate control, the AC button lights up (ie yellow bar on the display). Should we be concerned about this? Is the AC actually running at all times? When the cabin is being heated, the AC button is still illuminated. Are they working against each other or is the yellow bar just indicating that the AC is in "ready" mode and able to activate as needed?

 

<div class='quotetop'>QUOTE(dgstan @ Jan 31 2007, 11:55 AM) [snapback]383440[/snapback]</div>

There are other threads that describe in detail how the whole system works. However, the short answer to your question is that the yellow bar is just indicating that the ac is in "ready" mode - and will activate as needed. (It is not always on).

 

<div class='quotetop'>QUOTE(dgstan @ Jan 31 2007, 11:55 AM) [snapback]383440[/snapback]</div>

Read this thread so you can understand what the system is trying to do and then try it again. This should answer most of your questions.

http://priuschat.com/index.php?showtopic=28975&hl=