Warm air from vents

[DoomsdayJesus]

Originally Posted by FRiSson

Putting recirculation on is not a solution, not only will the air become stale, but humidity builds up in the cabin and eventually fogs the windows.

Only if you do it after running the A/C or live in a humid climate. And if the fan's off, it won't do diddly.

Originally Posted by FRiSson

It reflects poor design on Toyota's part that the outside cabin air intake tubes are insufficiently insulated from engine compartment heat.

Your statement about saving gas is obviated by the fact that even when the temperature outside is 60 farenheit I must turn on my air conditioner to maintain a comfortable cabin temperature. These are times when I keep my windows closed due to traffic noise.

No it doesn't reflect poor design, practically every damn car known to man does this because the intake for every car is behind the hood. So whether you get heat from the engine compartment or off the hood, you're going to get heat. So you can get some foam or rubber weather stripping and seal off the back of the hood if it really bothers you that much (which I did on my old SRT-4 and it worked great since the turbo was below the HVAC intake, but you're negating a great way for your engine bay to dump heat).

Also, dropping your windows below 50 isn't that awful. Your grandparents did it for the first half of their lives at least.

Originally Posted by fistpoint

I never use recirculate, ever. And I shouldn't have to start now.

This is a dumb statement. There are TONS of valid reasons to use recirculate, especially A/C efficiency and reducing vehicle exhaust going into your lungs (which is really, really bad for you over time and in traffic, and is responsible for an awful lot of lung cancer behind cigarettes).

Originally Posted by mike the snake

On my BRZ, my AC is capable of blowing icy cold, but it cycles on and off and never blows super icy cold (issue #1).

With the system off, my car blows warm air like other have stated. It blows harder when at speed, less when sitting. This tells me it has to do with something being open to the atmosphere, as high speeds equals more warm air blowing.

I think part of my issue#1 has to do with the AC having to overcome the warm air that's always blowing into the car.

Switching the fan on, temp to LO, and pushing the recirculating button, and then switching the system off doesn't change this.

The A/C compressor is connected to your engine. Higher RPMs = colder air. Recirculating cold air is why we have central cooling in modern houses that doesn't cost an arm and a leg.

And doing it properly and switching off should fix it.


Seriously, I don't know how this many people are completely void of HVAC knowledge on cars. My CRX did it. My 626 did it. So did my SRT-4, 330Ci, and Outback. This isn't 400 level thermodynamics, it's common freaking sense. Unless you want to put an HVAC intake snorkel on your damn car, it's going to blow warm in the summer.

Man up.

[andrew20195]

It should be noted that this car does not have a heater valve, so when your engine is at operating temperature, there is hot coolant circulating through the heater core at all times. If you aren't using a/c, and the air mix door isn't at full cold, you will definitely get some warm air.

[strat61caster]

Originally Posted by DoomsdayJesus

No it doesn't reflect poor design, practically every damn car known to man does this because the intake for every car is behind the hood. So whether you get heat from the engine compartment or off the hood, you're going to get heat.

I've got a 20 year old POS truck I bought for $1,000, the vents blow air from outside the car without heating it, i.e. I can leave the windows rolled up and still feel refreshed without the A/C on in pretty much anything below 90 degree heat. This is not possible with my FRS even when it's 70 outside.

A lot of people are used to that kind of HVAC system, you list off several cars which blow hot air unless A/C is on, but that does not constitute "every damn car known to man", different cars have different priorities when it comes to budget, it would have been nice to have the fans blow air close to outside temperature but we bought a sports car, not a refrigerator with wheels.

[fistpoint]

Originally Posted by fistpoint

I never use recirculate, ever. And I shouldn't have to start now.

Originally Posted by DoomsdayJesus

This is a dumb statement. There are TONS of valid reasons to use recirculate, especially A/C efficiency and reducing vehicle exhaust going into your lungs (which is really, really bad for you over time and in traffic, and is responsible for an awful lot of lung cancer behind cigarettes).

I do smoke, which is precisely why I never use recirculate. So you see, there are equally valid reasons to NOT use recirc.

Recirculate IMO is only good for when you need it to be colder than what is provided by the fresh air setting. If I drive behind a noxious vehicle, I turn off the fan until I pass. Using recirc after getting smogged out by a diesel piece of shit hickup truck only serves to lock in the stink. No thanks.

Originally Posted by DoomsdayJesus

Unless you want to put an HVAC intake snorkel on your damn car, it's going to blow warm in the summer.

Man up.

You don't say? I think that part is obvious and no one is questioning that. What we are concerned about is that it will keep doing it in the colder climates...unlike every single car I have ever owned. Of course warm air blows through during the summer, we're concerned that the warm outside air is being enhanced by even hotter engine air. If it's 90 outside, it shouldn't blow 95.

Is it really that difficult to comprehend? Warm outside PLUS hotter engine air = the issue we're conmcerned about. Warm outside air not being made hotter by engine air is not the issue.

And as I said with my disclaimer, I can't really comment further until the cold weather arrives. But the initial relatively cool day we had last week is making me worry. I still have 2 cars that I drive daily so I can compare without having to say I may have forgotten how the other car reacts to heat. I'll know in a month or two.

[mike the snake]

I have to disagree here. My last 3 cars (Saturn, BMW 135i, and Nissan Cube) all did not blow air of any kind, hot or cold, when the system was OFF.
If I wanted outside, non-air conditioned air, I turned off the AC, turned the recirculating to outside, and the fan blew fresh outside air.

When the systems were off, no air came out from the vents.

My BRZ blows outside/warm air when the system is off. It blows harder the faster I'm going, so air from somewhere is getting rammed in.
My AC is having to fight against this warm air when it's on.

This does not seem right to me.

Friday morning I'm going to the dealership and I'll find out from them then.

Originally Posted by DoomsdayJesus

Only if you do it after running the A/C or live in a humid climate. And if the fan's off, it won't do diddly.

No it doesn't reflect poor design, practically every damn car known to man does this because the intake for every car is behind the hood. So whether you get heat from the engine compartment or off the hood, you're going to get heat. So you can get some foam or rubber weather stripping and seal off the back of the hood if it really bothers you that much (which I did on my old SRT-4 and it worked great since the turbo was below the HVAC intake, but you're negating a great way for your engine bay to dump heat).

Also, dropping your windows below 50 isn't that awful. Your grandparents did it for the first half of their lives at least.

This is a dumb statement. There are TONS of valid reasons to use recirculate, especially A/C efficiency and reducing vehicle exhaust going into your lungs (which is really, really bad for you over time and in traffic, and is responsible for an awful lot of lung cancer behind cigarettes).

The A/C compressor is connected to your engine. Higher RPMs = colder air. Recirculating cold air is why we have central cooling in modern houses that doesn't cost an arm and a leg.

And doing it properly and switching off should fix it.


Seriously, I don't know how this many people are completely void of HVAC knowledge on cars. My CRX did it. My 626 did it. So did my SRT-4, 330Ci, and Outback. This isn't 400 level thermodynamics, it's common freaking sense. Unless you want to put an HVAC intake snorkel on your damn car, it's going to blow warm in the summer.

Man up.

[fistpoint]

Originally Posted by andrew20195

It should be noted that this car does not have a heater valve, so when your engine is at operating temperature, there is hot coolant circulating through the heater core at all times. If you aren't using a/c, and the air mix door isn't at full cold, you will definitely get some warm air.

Is it really that simple of an explanation? So those of us who have not experienced this on our previous vehicles must have had heater valves?

Is this something that can be added or would that constitute a whole new system?
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If we add Mike the Snake's comment about his previous vehicles not blowing at all when fan is set to off, then we have 3 distinct variations of vehicles HVAC systems:

1) no air leaks in when fan is off
2) air "leaks in when fan is off, but temp is relatively equal to outside air
3) air leaks in when fan is off, temp is hotter than outside air

[andrew20195]

Originally Posted by fistpoint

Is it really that simple of an explanation? So those of us who have not experienced this on our previous vehicles must have had heater valves?

Is this something that can be added or would that constitute a whole new system?

Subaru uses the heater core as a coolant bypass until the thermostat opens, so you'd have to plumb a bypass as well. Other than that, a heater valve would be fairly easy to add. Some manufacturers use cable controls, some use electric. You'd have to add a manual control for it since the HVAC isn't designed with a heater valve.

I should note that it hasn't been cool or cold since I got my BRZ. I'll make sure to check my car and see what I find when it does.

[DoomsdayJesus]

Originally Posted by strat61caster

I've got a 20 year old POS truck I bought for $1,000, the vents blow air from outside the car without heating it, i.e. I can leave the windows rolled up and still feel refreshed without the A/C on in pretty much anything below 90 degree heat. This is not possible with my FRS even when it's 70 outside.

A lot of people are used to that kind of HVAC system, you list off several cars which blow hot air unless A/C is on, but that does not constitute "every damn car known to man", different cars have different priorities when it comes to budget, it would have been nice to have the fans blow air close to outside temperature but we bought a sports car, not a refrigerator with wheels.

I said practically for that specific reason. Trucks are also farther off the ground where you're not picking up as much road heat. We get our air practically right off the asphalt. Old beaters usually had an awful lot of ventilation options as well, like windows behind A pillars and floor vents. I cried a little when they removed those from up-armored HMMWVs because they have a piss poor firewall. But realistically, our vents are intakes are tucked under the hood overhang for aerodynamics and to hide the windshield wipers, so it's a sacrifice for speed and MPGs.

Originally Posted by fistpoint

I do smoke, which is precisely why I never use recirculate. So you see, there are equally valid reasons to NOT use recirc.

Recirculate IMO is only good for when you need it to be colder than what is provided by the fresh air setting. If I drive behind a noxious vehicle, I turn off the fan until I pass. Using recirc after getting smogged out by a diesel piece of shit hickup truck only serves to lock in the stink. No thanks.

You don't say? I think that part is obvious and no one is questioning that. What we are concerned about is that it will keep doing it in the colder climates...unlike every single car I have ever owned. Of course warm air blows through during the summer, we're concerned that the warm outside air is being enhanced by even hotter engine air. If it's 90 outside, it shouldn't blow 95.

Is it really that difficult to comprehend? Warm outside PLUS hotter engine air = the issue we're conmcerned about. Warm outside air not being made hotter by engine air is not the issue.

And as I said with my disclaimer, I can't really comment further until the cold weather arrives. But the initial relatively cool day we had last week is making me worry. I still have 2 cars that I drive daily so I can compare without having to say I may have forgotten how the other car reacts to heat. I'll know in a month or two.

You must have had some fantastic cars if your vent air wasn't heated at least 5 degrees. I smoked for years and it wasn't that big a deal to turn on floor air, crack my window, and then go back to normal unless you chain smoke. Plus the A/C on this car is really damn efficient MPG-wise compared to other cars I've had, probably since the cabin's so small and it doesn't require a big compressor.

If it bothers you that much, like I said. Weather tape the rear underside of the hood (I had to do this on my old SRT-4 after I got a CF hood with no rubber strip in the rear, and I pulled it in the winter). I'm not saying it isn't annoying, I'm saying you expect way, way too much from cars. Particularly this one. It's not an Infinity trying to mimic a luxurious breeze, it's a low slung sports car with a standard HVAC pulling air from a couple feet off hot asphalt and with a recessed intake for aerodynamics. You could always get a bus driver fan.

Originally Posted by mike the snake

I have to disagree here. My last 3 cars (Saturn, BMW 135i, and Nissan Cube) all did not blow air of any kind, hot or cold, when the system was OFF.

I meant all cars heat outside air before/as it enters the intake. I really don't care about blowing when the system's off, mine's always on.

One other thing I found works well is windows down and recirculate on. That or weather stripping under your hood are really your only options.

[mav1178]

Originally Posted by mike the snake

I have to disagree here. My last 3 cars (Saturn, BMW 135i, and Nissan Cube) all did not blow air of any kind, hot or cold, when the system was OFF.
If I wanted outside, non-air conditioned air, I turned off the AC, turned the recirculating to outside, and the fan blew fresh outside air.

When the systems were off, no air came out from the vents.

Originally Posted by fistpoint

.
If we add Mike the Snake's comment about his previous vehicles not blowing at all when fan is set to off, then we have 3 distinct variations of vehicles HVAC systems:

1) no air leaks in when fan is off
2) air "leaks in when fan is off, but temp is relatively equal to outside air
3) air leaks in when fan is off, temp is hotter than outside air

My counterpoint/counterargument to the posted "problem":

- S13 240SX: blows air inside with fans off and recirculation off
- P10 G20: same
- P11 G20: same
- 2005 Camry: same
- 1992 Infiniti Q45: same

The air "leaking in" is a combination of the location of the intake of the A/C system, as well as any leaks in the cabin whether it's windows or something else. I've never found this to be a problem for my BRZ, and frankly it's welcomed as makes the car more fuel efficient, all else equal.

-alex

[fistpoint]

Originally Posted by DoomsdayJesus

You must have had some fantastic cars if your vent air wasn't heated at least 5 degrees. I smoked for years and it wasn't that big a deal to turn on floor air, crack my window, and then go back to normal unless you chain smoke.

'92 Civic Si, '93 Civic Si, '00 Civic Si, '03 RSX-S...all share common denominators: begin a Honda and being the small Honda. That's why my experiences have all been the same over the last 21 years.

Tested a little more in the RSX this afternoon. It was hot as usual but just for the hell of it I turned off the compressor and put my hand up to the vents. The air was relatively cool, definitely cooler than the outside air and absolutely night and day different from last nights FR-S compressorless test which blew warm air, not even remotely cool.

Even if it's hot outside, simply using your hand to fan your face produces "cool" air. I don't agree with your argument that all air is heated more when coming from the outside, I disproved it today for myself.

It's hotter than outside air in the FR-S while the RSX produced cooler than outside air. And yes, my test included parking the car in the heat for 5-10 minutes after turning the compressor off 10 minutes prior to parking. That way I could negate any doubt that there might have been cold air still lingering in the system. 10 mins of off followed by 5-10 minutes parked.

I think I'm just going to go with the lack of heater core argument as it makes the most sense. All this arguing back and forth over "my car did or didn't" only matters if we compare the same previous vehicles, which we clearly aren't doing. Again though, it may prove irrelevant as I won't know until we get actual cold weather.

Originally Posted by mav1178

My counterpoint/counterargument to the posted "problem":

- S13 240SX: blows air inside with fans off and recirculation off
- P10 G20: same
- P11 G20: same
- 2005 Camry: same
- 1992 Infiniti Q45: same

The air "leaking in" is a combination of the location of the intake of the A/C system, as well as any leaks in the cabin whether it's windows or something else. I've never found this to be a problem for my BRZ, and frankly it's welcomed as makes the car more fuel efficient, all else equal.

-alex

Right mav, we got that part covered. Those of us complaining are worried that when it is COLD outside, as in jacket required cold, there should NOT be warm air of any kind leaking or not leaking, blowing or not blowing. It shouldn't even be remotely warm or anything other than COLD until you manually move the temperature dial. If it is all the way on blue and the air outside is 50 degrees or less, warm air should not exist.

The "leak" isn't the concern, it's the temperature of the "leak" being hotter than it should be, especially if it's cold outside. Not the leak, but the temp of the leak. Leak is normal for some car, not others. Apparently hotter than outside is also considered normal due to the lack of the heater valve, which is what I'm going with as the answer.

Again, not the leak itself, but the temperature of the leak.
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edited to add: I was just recalling the memory of when I first discovered "leaking" vents in my cars many many many many many years ago. It was a cold night and I clearly noticed COLD air leaking in on my left hand...not warm I liked the "leak" and always have...until possibly now on this vehicle which has not fully been tested yet by me in this regard. I'm going to be angry if I require A/C during 50 degree nights. I'm expecting this to NOT be the case, but I am worried as it will not be equal to what I have become accustomed to for the last 21 years.

I'm hoping for a best case scenario of using "less dial" on the temp gauge during the sub 50 degree weather when you for the first time all year have to move the temp dial. I think Texas has gotten cold enough outside a handful of times to require a HALF setting of the temp dial, right in the middle of blue/red. Vehicles in Houston do not see all the way red temp dials, it just doesn't happen here, lol.

[DaJo]

Originally Posted by fistpoint

'92 Civic Si, '93 Civic Si, '00 Civic Si, '03 RSX-S...all share common denominators: begin a Honda and being the small Honda. That's why my experiences have all been the same over the last 21 years.

Tested a little more in the RSX this afternoon. It was hot as usual but just for the hell of it I turned off the compressor and put my hand up to the vents. The air was relatively cool, definitely cooler than the outside air and absolutely night and day different from last nights FR-S compressorless test which blew warm air, not even remotely cool.

Even if it's hot outside, simply using your hand to fan your face produces "cool" air. I don't agree with your argument that all air is heated more when coming from the outside, I disproved it today for myself.

It's hotter than outside air in the FR-S while the RSX produced cooler than outside air. And yes, my test included parking the car in the heat for 5-10 minutes after turning the compressor off 10 minutes prior to parking. That way I could negate any doubt that there might have been cold air still lingering in the system. 10 mins of off followed by 5-10 minutes parked.

I think I'm just going to go with the lack of heater core argument as it makes the most sense. All this arguing back and forth over "my car did or didn't" only matters if we compare the same previous vehicles, which we clearly aren't doing. Again though, it may prove irrelevant as I won't know until we get actual cold weather.





Right mav, we got that part covered. Those of us complaining are worried that when it is COLD outside, as in jacket required cold, there should NOT be warm air of any kind leaking or not leaking, blowing or not blowing. It shouldn't even be remotely warm or anything other than COLD until you manually move the temperature dial. If it is all the way on blue and the air outside is 50 degrees or less, warm air should not exist.

The "leak" isn't the concern, it's the temperature of the "leak" being hotter than it should be, especially if it's cold outside. Not the leak, but the temp of the leak. Leak is normal for some car, not others. Apparently hotter than outside is also considered normal due to the lack of the heater valve, which is what I'm going with as the answer.

Again, not the leak itself, but the temperature of the leak.
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edited to add: I was just recalling the memory of when I first discovered "leaking" vents in my cars many many many many many years ago. It was a cold night and I clearly noticed COLD air leaking in on my left hand...not warm I liked the "leak" and always have...until possibly now on this vehicle which has not fully been tested yet by me in this regard. I'm going to be angry if I require A/C during 50 degree nights. I'm expecting this to NOT be the case, but I am worried as it will not be equal to what I have become accustomed to for the last 21 years.

I'm hoping for a best case scenario of using "less dial" on the temp gauge during the sub 50 degree weather when you for the first time all year have to move the temp dial. I think Texas has gotten cold enough outside a handful of times to require a HALF setting of the temp dial, right in the middle of blue/red. Vehicles in Houston do not see all the way red temp dials, it just doesn't happen here, lol.

At that point I would just roll down the windows lol

That being said, I understand where you're coming from though...

[mike the snake]

I have an appointment tomorrow at 8am and I'll find out what Subaru has to say.

All I know is when I turn off my AC, it then is the same as if i turned the heater on. I get hot air from the vents and from the footwell area. The faster I drive, the harder it blows even with the system off.

This doesn't seem right to me.

[DoomsdayJesus]

This is the single dumbest argument I have ever taken part in. With the biggest whiners I've ever seen. This is not a Honda Civic, it's a purpose built car. Purpose built cars have design trade offs. and for the record, my 2011 Subaru Outback doesn't blow hot air (though hotter than ambient, and please don't make me explain wind chill), but I'm not going to feign surprise when a performance car does. Remember E46 grilles in the hood? Those heated up too. Ours are half buried completely underneath the hood and you're wondering why they're hot.

If it seriously bothers you duct tape the part completely under the hood. $10 says it's cooler.

[root]

The warm air even with dial at full blue kind made me wonder too. I asked my friend who has a Forester if his does it & it doesn't. All my other cars don't blow air close to this warm. There is some air flow even if fan is off if set on vent, with the exception of my LandCruiser which doesn't have much of a air ducting & vent design, that one is called flip out foot vent and wing windows.
The warm air bugs me a little because I end up using my A/C more than I might normally. I haven't gotten around to figuring out how the heater mixer works, it does feel like the heater valve isn't completely closed, but if the system on the FR-S doesn't use a valve that might explain things.