Electric Heater

as i remember. the only step was to set temp to max heat

 

<div class='quotetop'>QUOTE(DaveinOlyWA @ Feb 4 2007, 11:33 AM) [snapback]385120[/snapback]</div>

It's a bit more complicated. There are two small PTC heaters, each about 150W. There is a slight difference in when either comes on, although Dave is on the right track. Here is the page from the service manual (2006 vintage) that explains it:

[attachmentid=6441]

With so little watts available, I'm not sure why they bothered. I guess the one is useful for a slight boost for an early start on defrosting.

- Tom

 

well the reason is to get warmer air nearly instantly. if in sub zero weather, that is a valuable option.

but basically to max the benefit, set to max heat and have air control with feet involved

 

for a total of 300 watts and the fan blowing cold air over them your probably better off rubbing your hands together. A block heater is more usefull as you have heat nearly instantly as the ICE temp is above the threshold of the PTC heater.

 

660 watts.

 

150 x 2 = 300.

Anyway, I can assure you that in temps of -25 C, especially -40, I can't tell the difference. Without a winter front, my sad pointy bits almost fell off. However in temps *above* freezing say +8 C, they really do help.

Now if the ptc heaters were say 2,500 watts, that would completely change the picture.

 

<div class='quotetop'>QUOTE(jayman @ Feb 4 2007, 07:36 PM) [snapback]385303[/snapback]</div>

OK, my fault for not being precise. The actual value for each heater is 165 Watts. So the total is a whole 330 watts. A person puts out about 100 Watts of heat at rest, so this is like having 3 passengers in the car with you. That's not going to heat the cabin up much. I use the block heater and have real heat as I back out of the garage most mornings.

Here's a picture of the heater core from the technical training info that I posted the last time this came up:

[attachmentid=6446]

- Tom

 

Someone on anothe thread made the following statement,"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."

Can anyone varify this info? If so it would sem t support the 660 watt statement.

 

<div class='quotetop'>QUOTE(Tom_06 @ Feb 4 2007, 07:35 PM) [snapback]385335[/snapback]</div>

Where are you getting these documents? I would really like to get my hands on the whole collection!

 

<div class='quotetop'>QUOTE(Display Name @ Feb 4 2007, 08:57 PM) [snapback]385394[/snapback]</div>

those are out of the NCF manual. Toyota techinfo has them for download. costs money.

 

One thing I can say from experience... for what it is worth:

If I have the HVAC in manual control (AC button off, no auto, but I have the fan running ambient air) and thdn I press the button (either on the wheel or screen) for front windshield defrost, I get warmed air hitting the windshield. I am *guessing* that the resistive heater is always used in this situation. And I'll tell you this - I'm glad for it. Works great for a quick 30-second clearing of the windshield when I don't want to add heat to the cabin or wait for the heat pump to do its thing.

 

<div class='quotetop'>QUOTE(darelldd @ Feb 5 2007, 01:36 AM) [snapback]385430[/snapback]</div>

I've learned to use AC Auto all the time, which varies the fan speed by what temp you have set, and dries the air enough that I pretty much don't need to use the defrost all the time like I did the first few weeks driving the car. Then if I need to defrost I just press the button on the wheel and when it's done I press the same button again and it goes into AC Auto again. If I don't need any more air I press AC Auto again and the system shuts off.

Pretty cool, huh.

Dave

 

<div class='quotetop'>QUOTE(seasalsa @ Feb 5 2007, 04:53 AM) [snapback]385370[/snapback]</div>

Figure 6.2 above shows the core PTC heaters; figure 6.3 is showing the footwell heaters. For some reason the text there doesn't mention the footwell heaters; perhaps it's on the next page.

And also the table shown on page AC-17 above clearly distinguishes the two types of PTC heater.

The two heaters in the core take the form of film strips slotted into the vanes of the core. The footwell heaters are honeycomb shaped ones that the footwell air passes through.

 

<div class='quotetop'>QUOTE(Frank Hudon @ Feb 5 2007, 12:16 AM) [snapback]385403[/snapback]</div>

$10 if you are in the USA (look for the Toyota techinfo website). And you need broadband and about a day to snag all the files.

 

<div class='quotetop'>QUOTE(KMO @ Feb 5 2007, 04:43 AM) [snapback]385451[/snapback]</div>

It is not on the next page. After searching both the service manual and electrical manual (aka wiring diagrams) I am fairly sure that there are actually only the two PTC heaters in the heater core. One is in the duct that goes to the front footwells, the other the "core" that ends up at the defroster. There is a place that talks about right and left footwell heaters, but I suspect that is one of many Japanese-> English manual funnies.

The wiring diagrams (which include a very confusing "where things are" picture) only show two heaters, both in the heater core distribution box. There are two fuses in the box under the hood, one for each heater. The fuses are 30 A each. If each fuse supplied 330W from their 12V feed, that works out to 27.5 Amps. At least when I was doing circuit design, you never put a 27.5 A load through a 30 A fuse - fuses aren't that precise. A 100% derating was common, and that matches a 165W load for each heater.

The manuals are confusing. I interpret the bulk of the material to say there are only the two heaters located in the heater core box, each 165W. It states in a couple of places that one of these is the footwell heater. I can't find any separate footwell heaters, connectors, fuses, or parts locations. So I conclude the total electrical heater wattage is 330W, not 660W

- Tom

 

<div class='quotetop'>QUOTE(DaveinOlyWA @ Feb 4 2007, 11:33 AM) [snapback]385120[/snapback]</div>

Must be something about Prius units operated in the US Northeast because I have NEVER obtained MPG like these. The best was 49 mpg on the first 600 miles after I picked up the 06 vehicle in September. Mileage steadily dropped into the high 20s, then built up to its current 37-39 mpg. I spoke with my Toyota service department. They were mystified. They said a Prius technical specialist would be visiting the dealership in early December and would ask me to bring in my Prius for a look see. It is now mid-February. No call from the dealership. So I've stopped reading all these seemingly 'out of this real world' mileage figures posted and have settled for what the mileage my little doodlebug is getting. It is more than double what the Dodge Grand Caravan got, the Prius is a delight to drive, very comfortable on long trips, and so far does amazingly well for such a light vehicle in the deep, heavy snow and bitterly cold weather we're experiencing in Upstate New York. -- Chuck Kershner, executive editor, Clinton (NY) Courier Newspaper

 

<div class='quotetop'>QUOTE(chuck kershner @ Feb 10 2007, 07:54 AM) [snapback]388025[/snapback]</div>

Read this article: "Why Don't I get the EPA Mileage"?? (Written by efusco)

 

<div class='quotetop'>QUOTE(IsrAmeriPrius @ Feb 10 2007, 11:35 AM) [snapback]388033[/snapback]</div>

Thanks for the reference. There is some good information about maximizing mileage, and yet there are plenty of stated reasons why this may not occur, among them my very short trips (a mile or less about town with each trip). After nearly six months of owning the Prius, I just enjoy driving this vehicle. My wife nicknamed it "Zippy" because, unlike her Volvo V70AWD wagon, the Prius just zips around town. My college son nicknamed the GPS system "Victoria" - he loves listening to her voice on imaginary trips around the country he sets up just to see how Victoria would lead him to his destination! So we all have our little stories about this amazingly interesting, entertaining, fuel-efficient, fun-to-drive car.

 

<div class='quotetop'>QUOTE(chuck kershner @ Feb 10 2007, 11:45 AM) [snapback]388036[/snapback]</div>

Did you block your grill?