Defrost / Defog: Just want fan

[mknmike]

I now see that setting the temp to 60 seems to keep the heat pump off. I can hear it gear up somewhere between 62 and 65 F.

I’ve figured out that hitting the defog button is my problem and just keeping the temp at 60, AUto-off, AC-off, air only to windshield, fan at 1 or 2 seems to work pretty well. All the steps I mention above are not required, and I can turn it on by touching the temp, and off by holding the temp. I will see if I can post a video. It’s MUCH simpler now that @Big Earl helped me understand. Thank you!

 

[Foxsbiscuits]

Is this not the same as setting it to fully auto 60? I can't help but think you've gone round the houses to end up at the same place, unless I'm missing something.

And doesn't this setup only work for like... One week ... before temps change and requiring further adjustments?

I mean, I'm glad you've got what you were after it just seems very convoluted and unnecessary, but perhaps I've not understood enough.

I keep wanting to say don't fear the AC
Just try it first and see if it does what you want, regardless of efficiency fears.
It's vastly better at defogging because it dries out the air, and auto defog in my car isn't always hot, often it's just ambient temperature and aimed at the windscreen.
I'm not convinced I'll convince you though!

 

[mknmike]

I now see that setting the temp to 60 seems to keep the heat pump off. I can hear it gear up somewhere between 62 and 65 F.

I’ve figured out that hitting the defog button is my problem and just keeping the temp at 60, AUto-off, AC-off, air only to windshield, fan at 1 or 2 seems to work pretty well. All the steps I mention above are not required, and I can turn it on by touching the temp, and off by holding the temp. I will see if I can post a video. It’s MUCH simpler now that @Big Earl helped me understand. Thank you!

Stay away from the defog / defrost button is what I generally want to do. So simple. Thank you!

 

[mknmike]

Is this not the same as setting it to fully auto 60? I can't help but think you've gone round the houses to end up at the same place, unless I'm missing something.

And doesn't this setup only work for like... One week ... before temps change and requiring further adjustments?

I mean, I'm glad you've got what you were after it just seems very convoluted and unnecessary, but perhaps I've not understood enough.

I keep wanting to say don't fear the AC
Just try it first and see if it does what you want, regardless of efficiency fears.
It's vastly better at defogging because it dries out the air, and auto defog in my car isn't always hot, often it's just ambient temperature and aimed at the windscreen.
I'm not convinced I'll convince you though!

It’s easy to run the AC or heat. I wanted to know how to do it without a ton of steps every time I want to run the. Lower without AC or heat pump. I’ve got it now. Video posted above of what I’m after and how I set it.

 

[Foxsbiscuits]

Cool, can you send me your heat pump if you aren't using it?

I'd be interested in a comparison of efficiency between this setup and full auto.

 

[mknmike]

Cool, can you send me your heat pump if you aren't using it?

I'd be interested in a comparison of efficiency between this setup and full auto.

Well, knowing that my heat pump used ~10% of my battery defrosting the car the other night, just trying to be able to get into the car after a snowstorm, it’s clear to me that it uses a significant amount of battery power.

Just hearing the sound of the heat pump is enough for me to believe it’s taking a significant amount of power.

Obviously I need my heat pump, but I prefer to only use it when needed.

 

[Foxsbiscuits]

Full defrost is an extreme use case, you are literally superheating the car as fast as possible, that includes battery heating, window and mirror defrost, AC max hot. I think it hits and maintains like 28C (82F)

Please don't use that as an example of the heat pump's average energy usage...!

Daily AC is generally a small %, especially with a heat pump, and I think if you saw the stats you'd have a less stressful/more fun time just driving and using the car. Of course you can do what you like, it's your car etc, but I think you might be doing it based on bad data.

 

[mknmike]

Full defrost is an extreme use case, you are literally superheating the car as fast as possible, that includes battery heating, window and mirror defrost, AC max hot. I think it hits and maintains like 28C (82F)

Please don't use that as an example of the heat pump's average energy usage...!

Daily AC is generally a small %, especially with a heat pump, and I think if you saw the stats you'd have a less stressful/more fun time just driving and using the car. Of course you can do what you like, it's your car etc, but I think you might be doing it based on bad data.

Ernagerd. I’m not sure you understand the purpose of this thread. I wanted to learn how to do something. Big Earl helped me learn. I learned. I’m happy. Sorry if I frustrate you with my quest to learn and not care much about your perception of how little energy is used (wasted in my opinion) by the heat pump and heating for the windshield, something totally unnecessary on a dry sunny day when the cabin is steamy warm with 5 occupants sweating. Fresh air on the windshield was what I wanted to learn how to use without AC or Heat pump. I think I’ve got it now and am happy. I like to understand things instead of just trusting the designers and engineers. Sorry if my intent was not clear enough to you. If it makes you happier to know, this morning, even with the butt warmer and steering wheel heater on high, I decided 60 F was not warm enough for my windshield air, and I actually upped the temp to 70 knowing the heat pump would run. I wanted to be more comfortable and deciddd to expend energy. Does that make you happier to know that?

 

[Foxsbiscuits]

Heat Pump PTSD

I’m not sure you understand the purpose of this thread

Yea I think that's true, sorry if I got on your case!
My main intention was to check your data for assumptions. This car has a lot of tech and data, more than most of us really understand, so I think its good to dig into it when we're making changes to help understand what the effects are.
I was intrigued by your post, then I got lost about the purpose of it, but I think you just want to do it this way.

My happiness is unaffected by your butt warming

 

[mknmike]

Looks like some similar frustrations voiced in the X forum. I assume most of the software is the same, but really do not know. HVAC Auto mode- who came up with that garbage?

Edit: the side window fog might actually be a reason that REQUIRES that you run the AC / Heat pump and make the cabin as toasty as possible. When I was scraping ice off the cars, clearing off the ICE vehicles was much easier bc all their excess heat is blown all over the place including into the doors. Getting the ice off the Tesla literally took days after the recent snowstorm and ice that preceded it. I think it took at least 10-15 minutes of heating to be able to get into the Tesla and it still required force that had me wondering if I was going to damage the paint or seals on the car. This was after trying to melt away the ice with my bare hands and breath. My first experience with this made me realize this car needs to be kept in a garage during snowstorms and ice storms.

 

[Foxsbiscuits]

It got below freezing here recently and I'd run defrost for a good twenty minutes to make everything unstick properly.
The bonnet remained super frosty and I just left all that be.

They're surprisingly capable in the cold IMO, turning up to a toasty car beats anything I've driven before. The main thing I had to do was change the cabin filters, they were completely clogged so air was too weak to flow through the handles, mirrors, and charge port.

You can get a product called Gummifledge that you apply to the rubber seals to reduce winter sticking.

 

[Marzio]

if i start driving with the car cold, without having switched on the air conditioning, as soon as i try to switch it on the entire front window fogs up, to the level of total fog. only after at least 100 metres does the air conditioning manage to bring visibility to the optimum level.
changed filters and cleaned ducts, no improvement.

any ideas ?

 

[Foxsbiscuits]

If you don't use Aircon much it's possible the filters are damp so when you start it up it's just drawing all that dampness from the filter into the car.
100 metres sounds quick to clear. I'd say if you know that's coming just do it when you start the car.
It's another reason just to leave it on auto, unless it's properly mild weather.

 

[mknmike]

I can’t remember who posted the YouTube video, but the guy put a camera in the model 3 air intake and proved that when the fan is on high, rather than outside water draining out the bottom, it is sucked up and blown into the filter and gets it all wet. In the video, several solutions to the problem are offered, and the simplest seems to be not running the fan on high, at least not when the car is wet.

 

[mknmike]

Today is the first “road trip” in the Tesla, 2 hours and 20 minutes in the car with 5 people. We talked about maybe taking a different vehicle and still can, but it’s charged to 100% and ready to go. Tomorrow we will drive home in rain. So this will be a good test to see just how much AC is required. Good chance I will just let Auto do it’s thing, but I will probably try running without it today where it’s just foggy.

 

[pnwadventures]

I can’t remember who posted the YouTube video, but the guy put a camera in the model 3 air intake and proved that when the fan is on high, rather than outside water draining out the bottom, it is sucked up and blown into the filter and gets it all wet. In the video, several solutions to the problem are offered, and the simplest seems to be not running the fan on high, at least not when the car is wet.

I think this is what you're referring to:

 

[pnwadventures]

At the risk of misdirecting this entire thread, I'll share some of my own experience with a '19 3 (with resistive heating, which uses far more energy than even the heat pump).

A few years back I drove across the Cascades (WA state) the long way, starting on the west (Puget Sound vicinity) and heading east over the mountains, and then north into the North Cascades, in the winter (destination: heli skiing). There are no superchargers in this area (see map), and I had to rely on ~8A extension-cord L1 charging at my friends' cabin in freezing weather overnight to reclaim enough range for the return trip the following day.

On the remote stretches, I wanted the heat off in order to maximize my range, but I also needed to keep the windshield from fogging up. I found no good way to do this (similar to OP's initial problem), and ended up having to alternate between running the defog and turning off all climate control. Of course I used my seat heater, was dressed warmly, and had windows cracked at times to help. If I had been able to figure out an easy way to just have the fan running low on the windshield without any heat or AC sneaking on, I would have done that. Perhaps there is a way, but if there is, it's an unintuitive kludge.

Also FWIW, cutting out the climate energy budget helped dramatically and I recall making EPA range estimates on the return leg even in frigid weather. Also note that since I first did that trip, a new SC has opened in Entiat, which would have made this a lot easier. Also, there are a few L2 stations in the eastern North Cascades (Mazama, Winthrop, etc), but reliability and availability on that is low.

 

[mknmike]

I think our trip today was only about 108 miles, but our 271 range is only about 105 miles left at our destination even with mount using any AC. I did have temp set at about 63-65 most of the trip with fan speeds between 1 and 5. Will need to supercharge on way home tomorrow.


Highway speed was 75-80, mostly 78

 

[Big Earl]

if i start driving with the car cold, without having switched on the air conditioning, as soon as i try to switch it on the entire front window fogs up, to the level of total fog. only after at least 100 metres does the air conditioning manage to bring visibility to the optimum level.
changed filters and cleaned ducts, no improvement.

any ideas ?

Turn on the climate control five minutes before you go to use the car.

 

[Big Earl]

Perhaps there is a way, but if there is, it's an unintuitive kludge.

Explained in post #9

You can do just air to the windshield by selecting the windshield vents, setting a manual fan speed, setting the temperature to LO and deselecting A/C. This will do fan only. With five people, you’ll probably need a fan speed of at least 4.