A/C off but blowing cold air

So with the temperatures (and humidity) starting to dip, I'm trying to use less A/C and gain more range. However, the last few times that I've pressed the A/C button off and opened the window, I still find cold air blowing out of the vents.

It seems that if I turn the HVAC system completely off (fan to 0) and then back on, only then do I feel non-refrigerated air.

I'm on the current/latest s/w update.

FWIW, the 'fan' switch is more about how aggressively the climate control tries to maintain the temperature, which only partly includes controlling the fan speed. That being said, there are also conditions when the car will turn the a/c on regardless of your settings, primarily to prevent fogging of the windows, if it detects those conditions exist. So, hard to say. If the a/c had been on, it will take a few minutes to completely rewarm the evaporator coils before the air will reach ambient.

Also, if most of your driving is over 30mph (about 50km/hr), you're wasting battery capacity as the drag from the open windows is more than running the a/c once you exceed that speed.

Even without opening the windows it still pumps cold air.

Are you running in Comfort mode or EcoPro? My i3 doesn't deliver heated air when running in EcoPro.

BMW4Me said:

So with the temperatures (and humidity) starting to dip, I'm trying to use less A/C and gain more range. However, the last few times that I've pressed the A/C button off and opened the window, I still find cold air blowing out of the vents.

It seems that if I turn the HVAC system completely off (fan to 0) and then back on, only then do I feel non-refrigerated air.

I'm on the current/latest s/w update.

Click to expand...

Simplest solution is to switch to Eco Pro + mode. It deactivates cooling and heating modes of the climate control system with a single button.

If I switch my AC off and leave the fan on it does not blow cold air in Comfort or any other mode.

Mike S

Very interesting. If I understand you correctly, in EcoPro your car will blow hot air?

If I leave the AC off the fan just blows in air at ambient temperature, which is what I expect.

OK. Same as mine.

Just to check, if you are on EcoPro and turn temperature up on auto do you get heat? And do you get heat on Comfort setting?

BMW4Me said:

So with the temperatures (and humidity) starting to dip, I'm trying to use less A/C and gain more range. However, the last few times that I've pressed the A/C button off and opened the window, I still find cold air blowing out of the vents.

It seems that if I turn the HVAC system completely off (fan to 0) and then back on, only then do I feel non-refrigerated air.

I'm on the current/latest s/w update.

Click to expand...

I've observed the same symptom. I was driving on a relatively cool day this summer, outside temp in the high 60s. The car was in 'Comfort' mode and the climate system was in 'Auto'. I set the temp to about the outside temperature and turned off the A/C, or at least pressed the A/C button so the light went out. I continued to get refrigerated air, just as you say. The only way to stop this that I found was to put the car in EcoPro+ mode, which has other side-effects, such as making the car less responsive and limiting the speed to 56 mph, a ridiculous way to have to turn off the A/C. I'd much prefer that the car do what I told it to do when I pushed the damned button.

There's a lot about this car that, in my opinion, is overly complicated, overly automated. The automatic rear-view mirror is ridiculous. I just want the mechanical lever so I can flip the mirror myself. But no, BMW thinks we won't buy the car if we have to do that much work (and they might be right in many cases; we have become absolute spoiled brats in my 73-year lifetime). Same for the windshield wipers; overly complex and difficult to control.

I find that I much prefer driving my VW Jetta TDI with a stick shift. The car has a mechanical tach, speedometer and other instruments, and manual controls for heat, A/C, and an actual lever on the rear view mirror. Fortunately, the i3 is my wife's car, though neither of us are driving it because it's in the shop getting its EME replaced after 3400 miles, as I discussed in another thread.

If you stop to think about it, an EV climate control system ranks as one of the most radical redesigns from automotive engineering conventions of the past 60 years. In every ICE I know of, the climate system is utterly dependent upon the engine. The compressor is belt driven off the flywheel; air is chilled to a low temperature; then brought up to the desired temperature by the heater core, which employs waste heat from the combustion process. None of those factors are present in an EV of course so the climate systems have to be completely independent. A side benefit is that the system can run even when the rest of the vehicle is off, hence the stationary and pre-conditioning options.

Rather than complain that these very different systems don’t behave exactly as you expect, maybe you should consider what you’re trying to accomplish. In an ICE, a driver turns off the AC compressor to reduce the parasitic drag on the engine—either for performance or efficiency. The EV climate system has no performance penalty so that’s a non-issue. If you want increased efficiency in an i3, EcoPro+ is the best choice. Finally if you local weather is such that you don’t need cooled, heated, or dehumidified air flow, simply turn the system off and open a window.

Is it possible (just guessing) that in addition to temperature the car has a humidity sensor and will engage the compressor to dehumidify regardless of AC on? I say this because in the Leaf if you turn off the AC the interior will rapidly start condensing with humidity, and although I have turned "off" the AC I have not seen this happen in the i3. And I had not thought of it until I was reading this thread.

So maybe the difference in behaviour is due to what the humidity is?

stumbledotcom said:

The EV climate system has no performance penalty so that’s a non-issue.

Click to expand...

An EV climate system reduces the range which is a performance component, but it does not reduce the propulsive power as it does in an ICE vehicle which may be your point.

stumbledotcom said:

Finally if you local weather is such that you don’t need cooled, heated, or dehumidified air flow, simply turn the system off and open a window.

Click to expand...

I wish the i3's climate control system would allow outside air to flow through the climate control system without the fan being on.

alohart said:

stumbledotcom said:

The EV climate system has no performance penalty so that’s a non-issue.

Click to expand...

An EV climate system reduces the range which is a performance component, but it does not reduce the propulsive power as it does in an ICE vehicle which may be your point.

stumbledotcom said:

Finally if you local weather is such that you don’t need cooled, heated, or dehumidified air flow, simply turn the system off and open a window.

Click to expand...

I wish the i3's climate control system would allow outside air to flow through the climate control system without the fan being on.

Click to expand...

Verses running with open windows, no, the climate control SAVES energy because over 30mph, the drag of an open window is greater than the power used to run the a/c system. Only if you're comfortable with the windows up AND the climate control off, would running in that mode improve range. On a BEV, unless the heating requirement is greater than the heat pump (if equipped - all in the USA are) can provide, the same thing applies. You might save some energy running the seat heater alone verses the climate control in the winter...depends on your tolerance levels and desire to save a watt.

Yes, the i3 has sensors that detect the windows fogging up and will turn on the climate control even in eco pro+ mode.

alohart said:

An EV climate system reduces the range which is a performance component, but it does not reduce the propulsive power as it does in an ICE vehicle which may be your point.

Click to expand...

Yes, I was attempting to distinguish between propulsion and efficiency. Perhaps acceleration would have been a better word choice.

I'm old enough to remember the hit a compressor would inflict on the anemic four-cylinders common in the late 70s. A friend had a Datsun B-210 (a truly horrific car); he had to kill the ac anytime he required power for an extreme stunt such as passing a slow-moving tractor on a two-lane road.

jadnashuanh said:

Verses running with open windows, no, the climate control SAVES energy because over 30mph, the drag of an open window is greater than the power used to run the a/c system.

Click to expand...

You have stated in the past that BMW makes this claim, but Honda made a similar claim with our very aerodynamic Honda Insight (0.25 Cd) which isn't true for our Insight in actual practice, even as fast as 55 mph.

I drive the same route repeatedly at the same 40 - 55 mph, depending on the speed limit, but with stop lights, so my average speed varies. The efficiency of our i3 seems lower on this route with the A/C on than with it off and the driver's window fully open, but I can't be certain that the trade wind velocity was identical during these drives. Maybe I could try driving at a constant speed greater than 30 mph on flat terrain and compare the instantaneous efficiency with the windows up and A/C on and then windows down and A/C off. I'll have to give that a try after I return to Honolulu.

alohart said:

I wish the i3's climate control system would allow outside air to flow through the climate control system without the fan being on.

Click to expand...

It's been several decades since I saw a free-flowing ventilation system, regardless of brand. Could it be that the micro-filtration systems so common now need forced air to work properly? I learned to drive in a Saab 99 that had big, hooded air inlet at the base of the windshield feeding directly to the dash vents—each with an individual lever that switched between unadulterated outside air and heat. When you switched to outside air, I don't think there was any kind of filtering. I recall finding small sticks and leaves in the vents.

In terms of A/C vs windows open, you might like this from Auto Express in 2008.

http://www.autoexpress.co.uk/car-news/31861/mpg-mythbusters

Open windows
Here’s another piece of accepted wisdom for getting the most out of a tank of fuel; if you have the air- con off, you should open the windows for fresh air. But only open them very slightly or it spoils your aerodynamics and cuts economy. After a couple of laps of Millbrook, we can safely say that’s rubbish! On the first run we had the front two open a third, and fuel economy was only a tenth off the baseline measurement. Going out again, with the two windows fully open, it knocked the figure down by a further two-tenths.

donallen said:

There's a lot about this car that, in my opinion, is overly complicated, overly automated. The automatic rear-view mirror is ridiculous. I just want the mechanical lever so I can flip the mirror myself. But no, BMW thinks we won't buy the car if we have to do that much work (and they might be right in many cases; we have become absolute spoiled brats in my 73-year lifetime). Same for the windshield wipers; overly complex and difficult to control.

Click to expand...

I loved the automatic dimming mirror in my old car so much that I decided I wouldn't buy a car again without one. Different strokes...

donallen said:

I find that I much prefer driving my VW Jetta TDI with a stick shift. The car has a mechanical tach, speedometer and other instruments, and manual controls for heat, A/C, and an actual lever on the rear view mirror.

Click to expand...

Funny automatic climate control is also something I'd never get another car without!

I'm sure some people prefer cars from the 60s (for example) over modern cars too, it just depends on what kind of person you are. The i3 is meant for extremely forward thinking/futuristic types. It sounds like that's not you and that's ok.

spinball said:

donallen said:

There's a lot about this car that, in my opinion, is overly complicated, overly automated. The automatic rear-view mirror is ridiculous. I just want the mechanical lever so I can flip the mirror myself. But no, BMW thinks we won't buy the car if we have to do that much work (and they might be right in many cases; we have become absolute spoiled brats in my 73-year lifetime). Same for the windshield wipers; overly complex and difficult to control.

Click to expand...

I loved the automatic dimming mirror in my old car so much that I decided I wouldn't buy a car again without one. Different strokes...

donallen said:

I find that I much prefer driving my VW Jetta TDI with a stick shift. The car has a mechanical tach, speedometer and other instruments, and manual controls for heat, A/C, and an actual lever on the rear view mirror.

Click to expand...

Funny automatic climate control is also something I'd never get another car without!

I'm sure some people prefer cars from the 60s (for example) over modern cars too, it just depends on what kind of person you are. The i3 is meant for extremely forward thinking/futuristic types. It sounds like that's not you and that's ok.

Click to expand...

Not that simple, I'm afraid. First of all, if I weren't a "forward-thinking type", I wouldn't have bought an i3, would I? Obviously, much of this is personal taste, but I'm talking about mis-use of automation -- automating things that, in my opinion, are better done manually. You might disagree, but I feel that the mirror is an example, as is the climate system. When dealing with any kind of machine, whether computer or car, I want a master-slave relationship with that machine. Guess who I want the master to be? In order to play that role, you have to have a mental model of how the machine will respond to its controls. This is exactly the problem with the i3 climate system. I push a button that most sane people would think would turn off the A/C, since the label on it is "A/C" and when I push it, the little light on it goes out. Imagine my surprise when the car continues to blow cold air on me. I am a retired computer professional and have built a lot of complex software systems. One of the key principles of good user-interface design is "The Principle of Least Surprise". When people sit there with puzzled looks on their faces, saying "why the hell did it do that?", you have failed miserably.Simple manual systems tend not to have this characteristic. I think this problem applies to the i3 in more than one place, but the climate system is the topic under discussion here.

Having said all this, I hope that when our car comes out of the shop with a new EME, it will be the reliable vehicle I paid a lot for, because despite my complaints, overall I like the car very much. And with seven grandchildren, I care a lot about reversing the damage we are doing to the climate. Electric cars can be an important part of that process.