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View Full Version : Heat - is it warm, or hot and cold?



idreamofmazda
11-26-2004, 05:58 PM
Maybe it’s just me, but when I have the heat on, and the car is warmed up, it feels like cold air is mixed with hot air. I found out that you couldn’t select re-circulate on, while any selection that defrosts the windshield. It just feel like I can get my feet warm, and the rest of me is cold, or vise versa. Am I crazy, or has anyone else experienced this so far? Maybe I am just getting old.:(

Xenon
11-26-2004, 06:26 PM
Automatically, Hot air is vented at the bottom vents and cold air is vented at the upper vents... This is because hot air rises and cold air sinks. Theoretically, the cabin\'s air should be well mised since the cold air will have the tendency to sink to the floor and the hot air will have the tendency to rise to the roof.

The only exception to this is when the knob for heat control is turned to one extreme or the other. Then it will he pure hot or cold (depending on where the knob is) coming out of all the vents.

So if the knob is in the middle,. your feet will be in a tropical rainforest while your head is in the arctic circle.

billyfo
11-26-2004, 06:41 PM
I have no problem about the heat. but still at the 1st speed is as weak as A/C, lucky I can adjust the temp to highest one (red zone)

S.F.W.
11-26-2004, 07:36 PM
I can never get the temp right....it drives me nuts, it goes from warm to hot very quickly.

Xenon
11-26-2004, 09:03 PM
I find that 2 white dashes left from centre is perfect for me. But I have it totally to the right until my cabin reaches to a comfortable level. Then I drop it to that point.

everfeb
11-30-2004, 12:21 PM
Just read on another forum that even if the A/C is turned off the A/C automatically comes on when the mode selector is on \"floor\" and any setting to the right of \"floor\".
I probably read that in owner\'s manual but forgot about it. Any setting to the left of \"floor\" and A/C does not come on unless you turn it on. This winter, to try to get some heat to my floor I\'m going to use the \"floor/dash vent\" mode but close the vents . Last winter, at under -15C or so, at idle and slow speeds around town when I had it in \"floor\" mode it felt like I was getting barely warm air to my feet regardless of fan setting. But when I switched to dash vent mode the air coming out of the dash vents was quite hot. As I used mostly the floor mode (which unbeknowst to me at that time automatically turned the A/C on) last winter, my gas mileage must have been affected also?

everfeb

Xenon
12-01-2004, 07:57 PM
yes, A/C affects gas milage.

However, it sounds like you are saying because of the A/C your feel were cold...

That is untrue. AC does not greatly affect the temperature of the air, especially when you are in the redzone of the temperature dial. when warm air flows through the compressor, it just removes the moisture in the air. When it does that it gives the impression that the air is cooler, but it isn\'t...

Just like 30 C in summer feels much worse when there is humidity (moisture).

Ther\'s no sense in getting hot air from the engine, and cooling it with the A/C if it\'s hot air that the driver wants in the cabin.

everfeb
12-04-2004, 01:12 PM
Xenon...Last winter I did not know that when mode was at floor heat the A/C was on.
I learned this just recently. All I am saying is that last winter in very cold weather when I compared how warm my floor heat \"felt\" to how warm the air \"felt\" coming out of the dash vent....it \"felt\" like the air from the dash vent was much much warmer than floor air. In fact, in an attempt to get more heat to the driver\'s floor I blocked my rear seat heater ducts off. I have also complained to my dealer about this. You are right...it is my impression that air going to floor is cooler. Perhaps air coming out of the floor vent is at the same temperature as the air from the dash vents but feels cooler because of the A/C. I don\'t know. All I know is that air coming out of dash vents \"feels\" much warmer than floor air and I would like to have this nice warm air \"feeling\" on my feet as well as my face. So I\'ll experiment with heater settings this winter and hope for the best. Maybe just knowing that floor heat is actually quite warm but just doesn\'t \"feel\" warm because of the A/C will somehow help???

Regards, everfeb

Melenium
12-05-2004, 12:25 AM
Originally posted by everfeb


Xenon...Last winter I did not know that when mode was at floor heat the A/C was on.
I learned this just recently. All I am saying is that last winter in very cold weather when I compared how warm my floor heat \"felt\" to how warm the air \"felt\" coming out of the dash vent....it \"felt\" like the air from the dash vent was much much warmer than floor air. In fact, in an attempt to get more heat to the driver\'s floor I blocked my rear seat heater ducts off. I have also complained to my dealer about this. You are right...it is my impression that air going to floor is cooler. Perhaps air coming out of the floor vent is at the same temperature as the air from the dash vents but feels cooler because of the A/C. I don\'t know. All I know is that air coming out of dash vents \"feels\" much warmer than floor air and I would like to have this nice warm air \"feeling\" on my feet as well as my face. So I\'ll experiment with heater settings this winter and hope for the best. Maybe just knowing that floor heat is actually quite warm but just doesn\'t \"feel\" warm because of the A/C will somehow help???

Regards, everfeb



When you flip the dial to \'floor\', the A/C turns on and affects all the air, not just the air coming out of the floor vents.

I noticed too that the air coming out of the dash vents seems warmer than the floor vents. Does it maybe have something to do with volume (ie more air going through floor vents, but not as warm)?

Xenon
12-05-2004, 02:41 AM
just a thought...

but also I think the floor air won\'t be felt as much, since (especially in the winter) there is no bare skin exposed, where as the dash vents blow on the skin on your face and hands.

All I\'m trying to say is that perhaps you don\'t feel the heat at the bottom because your body is insulated by your shoes/boots, pants etc. So it takes time for the air to penetrate the material of your clothing.

Again, jsut a thought, but I may be misunderstanding what you are saying... if so then don\'t mind me :sarc

everfeb
01-02-2005, 09:05 PM
XENON...a month later I reply, sorry. When I use \"dashvent\" mode and hold my hand near the dash vent then I switch to the \"floorvent\" mode and hold my hand to the floor vent...the heat coming out of the dash vent feels much warmer than the heat from floor vent. This is subjective, I\'ve never used a thermometre to measure. Just feels like floor air not as warm as dash vent air.

Since my last post on this thread I\'ve discovered that when I\'m in \"floor\" mode a lot of air comes out the \"defrost\" vent onto the windshield. One notch to left of \"floor\" and less air comes out of the \"defrost\". In the \"floor-dash\" mode little or no air comes out of the \"defrost\" vent. When I\'m in \"dashvent\" mode no air comes out of the \"defrost\" vent. So when in \"floor\" mode a lot of air blows out of my \"defrost\". This is probably why when in \"floor\" mode the air doesn\'t feel as warm as I think it should.

BTW...I do have an Oct/03 built 3 and I\'ve seen many posts from people with early builds complaining about HVAC...particularly A/C. But those with newer built 3\'s seem to be much happier. So this may be a \"quirk\" particular only to early built 3\'s?? Possible??

Anyway...I\'m DONE VENTING.

everfeb