[Sportstick]

Originally Posted by morphomeman

Let's call it a draw.

Appreciate your intent, but it's not a competition, nor a challenge. Given the detrioriation in post #984, I've relegated it to a dismissal. As said earlier, everyone can reach their own conclusions, no matter how diverse, understanding the risks/benefits.

[albertw]

Originally Posted by Xi-Xi

By what manner does the A/C somehow add condensation to the interior of the car or to the HVAC system itself?

Well, I suppose it's possible you really don't understand this. Apparently neither does Sportstick. On the possibility that your earlier post (which I took as derogatory and was mainly what prompted my fanboy comment) and this one are genuine requests for an explanation, I'll expand on my earlier post (#974).

The dew point is the temperature at which air holds all the water vapor it can. If the temperature is reduced further, some of the water vapor condenses - into suspended droplets as fog or cloud, or onto any surfaces it contacts.

When the air conditioner compressor is running, the surfaces of the evaporator coil (heat exchanger) get very cold (that's how it cools the air flowing through it). Air touching the coil is cooled well below the dew point, unless the relative humidity is extraordinarily low. In most places in North America, at temperatures high enough that air conditioning or dehumidification is desirable, condensation is forming on the coil whenever the compressor is running.

That condensation builds up on the coil until it runs off onto the housing and eventually out the drain port. When the compressor stops the system warms up to above the dew point, condensation stops forming and gradually the water dries out. However, if the engine is stopped before the HVAC system is dry, the water can escape only by diffusing out through the ducts and vents, which is a very slow process (hours to days, not minutes). Until it is dry, any mold spores in the water start germinating and if left there will attach to the system and grow a bit whenever more moisture is added.

Now, if you run AC all the time in humid conditions, so much condensation forms and runs off that it flushes away any mold spores and recently germinated spores before they can attach and start growing. This is, I think, why using the Auto setting can work to prevent mold under those conditions.

It's a different story where I live. It's never humid enough that using the AC to dehumidify is appropriate (unless it's raining), and air conditioning is needed for roughly one day in three for four months a year. Since my car often sits for a week at a time, it is critical that I get all the water out of the HVAC system before I turn the engine off.

The manual says that in Auto all the incoming air is first cooled and dehumidified (whether it needs it or not), then warmed if needed. That means condensation is forming inside the system nearly every time you start the engine. But when the outside air is cold it holds very little moisture, so there probably isn't enough water formed to flush the system of mold spores reliably. Just enough to get them growing. That's why I would rather have the air conditioner off unless I actually need it. Then I can make sure the system is dry before I stop the engine for what might be a week or two. (And that's why it's so annoying to have the compressor turn on when all I want is heat on the windshield. I have to make sure I drive around for a while with defrost off to make sure I dry out the system before stopping.)

There's also the issue that the compressor draws up to 1/3 hp, which is not completely trivial since it takes typically less than 25 hp to maintain highway speeds.

[Cabrio330]

Originally Posted by albertw

Well, I suppose it's possible you really don't understand this.

I appreciate that you reveal early in your post that you are a condescending prick. It saved me from reading the rest.

Just curious though, why do you think anyone would read anything from you since you are, after all, merely another "anonymous forum poster"?

[albertw]

Originally Posted by Cabrio330

I appreciate that you reveal early in your post that you are a condescending prick. It saved me from reading the rest.

Just curious though, why do you think anyone would read anything from you since you are, after all, merely another "anonymous forum poster"?

I try to give back what I receive. When someone says over and over again that I'm wrong without ever saying why or really explaining his position, then turns out not to even understand the very basic physics of the issue he's pretending to be an expert on, I figure I have the right to be condescending right back at him.

[Pray for Mojo]

I've never used the auto feature on climate control and don't have issues with smells or anything.

[Nyorky2428]

So what's everyone's take on the AC in the car?

... just kidding...

[Xi-Xi]

Originally Posted by albertw

Well, I suppose it's possible you really don't understand this. Apparently neither does Sportstick. On the possibility that your earlier post (which I took as derogatory and was mainly what prompted my fanboy comment) and this one are genuine requests for an explanation, I'll expand on my earlier post (#974).

The dew point is the temperature at which air holds all the water vapor it can. If the temperature is reduced further, some of the water vapor condenses - into suspended droplets as fog or cloud, or onto any surfaces it contacts.

When the air conditioner compressor is running, the surfaces of the evaporator coil (heat exchanger) get very cold (that's how it cools the air flowing through it). Air touching the coil is cooled well below the dew point, unless the relative humidity is extraordinarily low. In most places in North America, at temperatures high enough that air conditioning or dehumidification is desirable, condensation is forming on the coil whenever the compressor is running.

That condensation builds up on the coil until it runs off onto the housing and eventually out the drain port. When the compressor stops the system warms up to above the dew point, condensation stops forming and gradually the water dries out. However, if the engine is stopped before the HVAC system is dry, the water can escape only by diffusing out through the ducts and vents, which is a very slow process (hours to days, not minutes). Until it is dry, any mold spores in the water start germinating and if left there will attach to the system and grow a bit whenever more moisture is added.

Now, if you run AC all the time in humid conditions, so much condensation forms and runs off that it flushes away any mold spores and recently germinated spores before they can attach and start growing. This is, I think, why using the Auto setting can work to prevent mold under those conditions.

It's a different story where I live. It's never humid enough that using the AC to dehumidify is appropriate (unless it's raining), and air conditioning is needed for roughly one day in three for four months a year. Since my car often sits for a week at a time, it is critical that I get all the water out of the HVAC system before I turn the engine off.

The manual says that in Auto all the incoming air is first cooled and dehumidified (whether it needs it or not), then warmed if needed. That means condensation is forming inside the system nearly every time you start the engine. But when the outside air is cold it holds very little moisture, so there probably isn't enough water formed to flush the system of mold spores reliably. Just enough to get them growing. That's why I would rather have the air conditioner off unless I actually need it. Then I can make sure the system is dry before I stop the engine for what might be a week or two. (And that's why it's so annoying to have the compressor turn on when all I want is heat on the windshield. I have to make sure I drive around for a while with defrost off to make sure I dry out the system before stopping.)

There's also the issue that the compressor draws up to 1/3 hp, which is not completely trivial since it takes typically less than 25 hp to maintain highway speeds.

oh, Christ. Patronizing arrogance is so attractive! Here's what you do: turn it on, never turn it off. It'll be fine. Every vehicle I've ever owned has had the A/C engaged constantly winter and summer, but somehow there's never, ever been a problem with mold growth. In fact, the conditions you describe pertain to virtually every A/C unit in every car everywhere, but again somehow there hasn't been an epidemic of moldy A/C systems. Oh, it happens, I'm sure, but far more rarely than you're maintaining. Your theoretical concerns are overblown. FYI: you don't know as much as you think you do.

[TajoMan]

Originally Posted by albertw

That's why I would rather have the air conditioner off unless I actually need it.

You can turn off AC compressor and remained Auto temperature control.

Hit Auto button (AC light will lit), then push AC button.
AC compressor will remain off unless you manually choose defrost/defog mode.

As an mobile HVAC engineer, I know for the fact that Auto mode can perform the best for 99% of people.
However, HVAC is not only about working ideally. It's all about personal preference. Some want hotter, the others want colder...etc

These days, we do develop systems that work the best in Auto mode.
It still works fine in manual mode and no harm will be there. (but Auto is better controlled)

For the most automotive AC system, AC compressor will run almost all the time in Auto mode.
However, AC compressor will NOT run if ambient temperature gets below certain temperature (varies by manufacturer) to avoid icing on the evaporator.

I've noticed that the AC compressor in my car runs in 25F ambient. This is possible because the partial re-circulation. Even in fresh air intake setting, there can be partial warm air flow from interior, goes through evaporator.
This is mainly to dehumidify the interior to prevent fogging.
Typical human exhalation emits about 70 grams of moisture per hour. HVAC system needs to take care of that to clear the windshield.

BTW, AC compressor in our car is something called "variable displacement compressor". It does not have clutch.
Depends on compressor demand, compressor can vary it's output hence it can run very efficiently.
When it's cold outside, it will not draw much power (less than 1 hp).
(It can take up to 5~7 hp when it's very hot outside)

So, all the air always goes through evaporator first (regardless the compressor is on or off), then it goes through heater core if hotter air is desired.
The air gets colder and drier after the evaporator, then heated through heater. This way, it can defog effectively. Just blowing hot moist air to windshield will take more time for defog.

For mainstream cars, there is no "adding humidity" function. (some ultra luxury cars may have humidifier)

For the condensation management, all the evaporators have water repellent coating as well as anti bacterial coating. These coatings typically last about 2~3 years. That's why you start to smell after couple of years.
Some GM cars have 'after blow' functions to dry out the evaporator after the car is turned off.
Most cars, if you leave in Auto, molds can be somewhat washed out more often with condensation since AC compressor is running more frequently.

[TajoMan]

Originally Posted by albertw

Fog is a different issue. It can be deposited on surfaces that move through it, or on the HVAC system as it's pulled through. Only heat will evaporate the water under these conditions. I doubt very much that the Germans are smart enough to design a system that knows it's foggy out, but I could be wrong.

We sorta know when it gets foggy.
There is no humidity sensor but we 'guess' based on ambient temperature and how much hot air we need to blend to get to target interior temperature.

To defog, the best way is using defrost/defog mode. (which forces Ac compressor running, as long as the ambient is not too cold)
Auto mode also works very well to defog.

[MPBK]

Originally Posted by Mywifes335

1. No oil temp gauge
2. No headliner overhead handles
3. 2014 MY Bluetooth doesn't stream music without Tech option
4. Wheel fitment sucks
5. Non-M speedo and tach

(2) is wifey's top peeve.
Is there a way to install it? Parts available at dealer?

[Clear_Blue22]

Originally Posted by MPBK

(2) is wifey's top peeve.
Is there a way to install it? Parts available at dealer?

For about $50 download bimmercode app for your phone and purchase one of the pictured obd2 adapters. With that you can add enhanced BT, and code oil temp and speedo to be added to the pages that display at the bottom between the gauges you cycle through using the button on the end of the signal stalk. Look up the coding forums here for instructions. It's very easy to do. I coded several other things as well such as muting the annoying safety alarms for the seatbelt and the chime when you turn on on the car as well as the doors unlocking automatically when I turn off the ignition

[MPBK]

Originally Posted by rezilient

Does anyone else feel like the torque is lacking and driver engagement is a bit numb? Coming from an E39 M5 this may seem a bit absurd to some, maybe my expectations are too high, but I think because of the weight of the 2er is doesn't feel "peppy" off the line like the 135i does. A good example is when you're sitting at 1500-2000 RPM and just want to floor it, you aren't going to pull very hard unless you downshift. Thoughts? Maybe somethings wrong with mine.

I had that same feeling, until I found Sport+ mode.
Changes the car completely.

[MPBK]

Originally Posted by Clear_Blue22

For about $50 download bimmercode app for your phone and purchase one of the pictured obd2 adapters. With that you can add enhanced BT, and code oil temp and speedo to be added to the pages that display at the bottom between the gauges you cycle through using the button on the end of the signal stalk. Look up the coding forums here for instructions. It's very easy to do. I coded several other things as well such as muting the annoying safety alarms for the seatbelt and the chime when you turn on on the car as well as the doors unlocking automatically when I turn off the ignition

Appreciate the info, but you mixed up the question being asked.

[Clear_Blue22]

Originally Posted by MPBK

Appreciate the info, but you mixed up the question being asked.

Dang... yea my fault. I didn't realize I was replying to your reply. I meant to offer to info to the original post you replied to. As far as the handle I haven't seen anything at all with people putting in an upper handle on any of the forums here.

[Mehim]

Originally Posted by Clear_Blue22

Dang... yea my fault. I didn't realize I was replying to your reply. I meant to offer to info to the original post you replied to. As far as the handle I haven't seen anything at all with people putting in an upper handle on any of the forums here.

Needs a grab handle stat

[Sportstick]

Originally Posted by Mehim

Needs a grab handle stat

I questioned BMWNA about this a few years ago, as my wife complains as well, about its absence. They received feedback from Munich that aftermarket installation is not feasible due to the placement of the side curtain airbag module.

[Xi-Xi]

Originally Posted by TajoMan

You can turn off AC compressor and remained Auto temperature control.

Hit Auto button (AC light will lit), then push AC button.
AC compressor will remain off unless you manually choose defrost/defog mode.

As an mobile HVAC engineer, I know for the fact that Auto mode can perform the best for 99% of people.
However, HVAC is not only about working ideally. It's all about personal preference. Some want hotter, the others want colder...etc

These days, we do develop systems that work the best in Auto mode.
It still works fine in manual mode and no harm will be there. (but Auto is better controlled)

For the most automotive AC system, AC compressor will run almost all the time in Auto mode.
However, AC compressor will NOT run if ambient temperature gets below certain temperature (varies by manufacturer) to avoid icing on the evaporator.

I've noticed that the AC compressor in my car runs in 25F ambient. This is possible because the partial re-circulation. Even in fresh air intake setting, there can be partial warm air flow from interior, goes through evaporator.
This is mainly to dehumidify the interior to prevent fogging.
Typical human exhilaration emits about 70 grams of moisture per hour. HVAC system needs to take care of that to clear the windshield.

BTW, AC compressor in our car is something called "variable displacement compressor". It does not have clutch.
Depends on compressor demand, compressor can vary it's output hence it can run very efficiently.
When it's cold outside, it will not draw much power (less than 1 hp).
(It can take up to 5~7 hp when it's very hot outside)

So, all the air always goes through evaporator first (regardless the compressor is on or off), then it goes through heater core if hotter air is desired.
The air gets colder and drier after the evaporator, then heated through heater. This way, it can defog effectively. Just blowing hot moist air to windshield will take more time for defog.

For mainstream cars, there is no "adding humidity" function. (some ultra luxury cars may have humidifier)

For the condensation management, all the evaporators have water repellent coating as well as anti bacterial coating. These coatings typically last about 2~3 years. That's why you start to smell after couple of years.
Some GM cars have 'after blow' functions to dry out the evaporator after the car is turned off.
Most cars, if you leave in Auto, molds can be somewhat washed out more often with condensation since AC compressor is running more frequently.

I'm not sure that "exhilaration" was what you were going for there, but it still works perfectly.

Nice explanation, by the way.

[TajoMan]

Originally Posted by Xi-Xi

I'm not sure that "exhilaration" was what you were going for there, but it still works perfectly.

Nice explanation, by the way.

lol. Fixed it.
Thanks.

[MPBK]

Anybody know how to activate the headlight washer? There are no buttons.

[aerobod]

Originally Posted by MPBK

Anybody know how to activate the headlight washer? There are no buttons.

When the headlights are on and you wash the windshield they will activate the first wash, then every 5th after that until the engine is restarted.

[Xi-Xi]

Originally Posted by aerobod

When the headlights are on and you wash the windshield they will activate the first wash, then every 5th after that until the engine is restarted.

When I checked the coding for the headlight washers on mine, they were set to activate after 10 washes. I was wondering why they hardly ever activated. Have set them to 5 now, but they don't activate on the first windshield wash, only after 5. Probably that's also a coding issue, I don't know. In any case, no more headlight washers are being installed in the 2 series anymore anyway. I find them useful, especially with the amount of salt on the roads around here recently.

[albertw]

Originally Posted by Xi-Xi

oh, Christ. Patronizing arrogance is so attractive! Here's what you do: turn it on, never turn it off. It'll be fine. Every vehicle I've ever owned has had the A/C engaged constantly winter and summer, but somehow there's never, ever been a problem with mold growth. In fact, the conditions you describe pertain to virtually every A/C unit in every car everywhere, but again somehow there hasn't been an epidemic of moldy A/C systems. Oh, it happens, I'm sure, but far more rarely than you're maintaining. Your theoretical concerns are overblown. FYI: you don't know as much as you think you do.

Apparently you didn't bother to read the explanation for condensation that you pretended to ask for. If you did, then apparently you're not capable of understanding that your experience in soggy Pennsylvania is irrelevant to the climate I live in.

You might want to ponder, if you're capable of it, a conversation I've had a number of times:

Me (intending to commiserate): What have you tried to fix the moldy smell coming out of the vents?

Owner of older car: What moldy smell?