Keep your car de-fogged without using the heater

[DaveinOlyWA]

took the plunge and went and got one of those 6" fans designed for semi and truck windshields. a bit bigger than i wanted but was only $16 so if it does not work, i find something else to do with it.

well, prelim results. it DEFINITELY clears the windshield. it has two speeds. i have fastened it to the dash on the passenger side so it will not obstruct the view. the switch is on a two foot cord so a bit of stretch but reachable. has two speeds.

i velcro'd it into place and took it for a test spin. i waited until the windows were pretty fogged up (not long) before turning fan onto low speed (has two speeds) and it cleared up the window in about 90 seconds.

if i decide to keep it, will probably go for a more permanent mount. it has a screw mount but hesitant to put holes in the car while still leasing it although i am pretty sure i will be buying this one.

 

[ebill3]

"Foot + defog." You clean the windshield with your foot? Seriously, what is it?

:mrgreen: Yes what was that

Guess you missed 91040's answer several posts back. The mode setting for air to feet and defrost.

Bill

 

[evnow]

You have to use AC when defogging. AC stands for air condintioning - i.e. it "conditions" air, not only makes it cold. Conditioning really means dehumidifing air. Is everybody clear on that?

I have no problem with defogging either. It does take about a minute with, say 75F added to speed things up in colder weather. Normally I run it at 60F AC full blast for less than a minute. Someone said it works better (or heats better) when in D rather than Eco. Might try that too if in trouble.

Interesting observation that you can dehumidify the car faster with foot-defrost combo than defrost only. Gotta try that to see if it's true. I presume this was done at higher temps too (such as >70F).

We are trying to find out a way to defog without using heater (and thus least amount of energy). Ofcourse, if you use defrost it will clear quickly - but it uses upto 3.5 kW of power.

BTW, I've not found much difference between AC & non-AC - both in terms of defog ability & the amount of energy used !

 

[GaslessInSeattle]

...
BTW, I've not found much difference between AC & non-AC - both in terms of defog ability & the amount of energy used !

me neither, seems that AC is on either way.

 

[Nubo]

Wondering... Is there some kind of benign anti-fog chemical that could be used on the window?

Yes. Glycerin is an effective fog or frost preventer. I used that trick back in my starving student days driving an old VW Beetle. The Beetle's heating system (exhaust heat exchangers) was marginal when new. An old bug in the road-salted Mid-west? Forget it!

I learned that old pilots used to apply glycerin to keep their cockpit windows from icing up at altitude. I tried it and it worked quite well, actually.

The pure stuff can be had at a pharmacy. It's a thick syrupy clear liquid. Apply to the inside of a clean windshield and spread into a very thin layer with a lint-free cloth. A little goes a long way. It will be blurry for a bit but levels out into a clear view. Or you can buff most of it off but then the anti-fog effect is shorter-lived.

Glycerin is hygroscopic. It pulls moisture out of the air. So over time its effectiveness is gradually diminished. I used to get a week or two before I had to wipe down and re-apply. But it did keep me and my decrepit beetle on the road for a couple of lean years through Cleveland winters.

 

[IBELEAF]

This has been one of the most annoying issues I hope Nissan is listening

 

[kovalb]

...
BTW, I've not found much difference between AC & non-AC - both in terms of defog ability & the amount of energy used !

me neither, seems that AC is on either way.

The A/C compressor does run in Defrost mode, and cannot be turned off. However in Foot/Def mode I am pretty sure it can be turned off. Same logic every Nissan uses.

 

[Bassman]

19 degrees this morning. Turned on the defrost on downhill runs and occaissionally when the windshield fogged up excessively - set the temp at 60 it clears up quickly even when turning off the AC - draws usually about 0.75 to 1.25 KW but only for about 20 seconds to a minute, then again in about 5 minutes when windshield fogs again - getting 4.0 mi/KWh and not as cold in the cab.

 

[Rokeby]

Has anyone considered one of the RV/boat 12V mini dehumidifiers?
This one 5.5" x 8" x 14". Available on ebay and Walmart.
~$75, a bit pricey for sure, especially compared to Dave's fan.

The Sunpentown Mini Dehumidifier with TiO2 and UV Light SD-652Ti is a
cool device to negate humidity from the sir, allowing you to breathe easier.
This portable mini dehumidifier comes with a recessed grip handle that
makes it convenient to be carried or transferred. It features a UV light and
TiO2 mesh that work as a filter and kill harmful germs and pollutants.
The dehumidifier with UV light is an automated product which monitors the
water tank and functions accordingly. Once the tank is full, the device will
automatically switch off. This portable mini dehumidifier has no disturbing
compressor or refrigerant noise as it works on thermo-electric power usage
technology. The home dehumidifier comes in an attractive silver finish and fits
well anywhere.

Sunpentown Mini Dehumidifier with TiO2 and UV light SD-652Ti
* Moisture removal rate of 650ml per 24 hours at 86 degree F and 80% room humidity
* 2 liters water tank capacity
* Comes with a UV light and TiO2 mesh that kills germs and bacteria
* Operates automatically when unit is turned on
* Peltier (Thermo-Electric) Technology; no vibration, no compressor, no refrigerant;
* Full tank indicator light, an auto cut-off when the tank is full or removed and a
continuous drain option
* Includes 12-volt DC adaptor
* UL listed
The Sunpentown Mini Dehumidifier

I'm thinking, maybe hang it from a strap from the pax head rest.
Don't know about power though.
Is the 12V power port unswitched, that is it energized all the time?
If, so, could the dehumidifier be run during charging and have no effect on
charge level on departure.
Running the unit when underway would be a different matter.

 

[TomT]

I have one of these in the cabin of my boat and it works quite well.

Has anyone considered one of the RV/boat 12V mini dehumidifiers?
This one 5.5" x 8" x 14". Available on ebay and Walmart.
~$75, a bit pricey for sure, especially compared to Dave's fan.

 

[evnow]

The A/C compressor does run in Defrost mode, and cannot be turned off. However in Foot/Def mode I am pretty sure it can be turned off. Same logic every Nissan uses.

Right - with foot+defog, I don't find any difference between a/c on & off.

 

[Rietta]

This has been one of the most annoying issues I hope Nissan is listening

Totally agree - I have no garage and have had several other vehicles here and other than an older VW camper van have never had the kind of condensation problem I have with the Leaf. Some aspect of how it is designed makes for far worse condensation than other vehicles - even before you have the problem of trying to get it cleared away.

 

[GaslessInSeattle]

This has been one of the most annoying issues I hope Nissan is listening

Totally agree - I have no garage and have had several other vehicles here and other than an older VW camper van have never had the kind of condensation problem I have with the Leaf. Some aspect of how it is designed makes for far worse condensation than other vehicles - even before you have the problem of trying to get it cleared away.

my conclusion is that this issue comes up most in the transition from summer to fall to winter where the moist warm air of the warmer months condenses during the cool nights as it cools, getting absorbed into the upholstery and gradually accumulating. the car can become a damp sponge. Not an issue for ICE vehicles so much because at about that time you start using the heater without much thought which dries out the car. The solution, that myself and a few others have tried with success is preheating for a prolonged period and then opening up the doors for several minutes letting the hot moist air out... repeating this process till there is no more fog on the windows, that's when you know it's dry.

 

[SeattleBlueLeaf]

This has been one of the most annoying issues I hope Nissan is listening

Totally agree - I have no garage and have had several other vehicles here and other than an older VW camper van have never had the kind of condensation problem I have with the Leaf. Some aspect of how it is designed makes for far worse condensation than other vehicles - even before you have the problem of trying to get it cleared away.

my conclusion is that this issue comes up most in the transition from summer to fall to winter where the moist warm air of the warmer months condenses during the cool nights as it cools, getting absorbed into the upholstery and gradually accumulating. the car can become a damp sponge. Not an issue for ICE vehicles so much because at about that time you start using the heater without much thought which dries out the car. The solution, that myself and a few others have tried with success is preheating for a prolonged period and then opening up the doors for several minutes letting the hot moist air out... repeating this process till there is no more fog on the windows, that's when you know it's dry.

in my case - i crack the windows slightly at night and when I do preheat in the morning, all is good. I park in a garage though.

 

[DaveinOlyWA]

i also open my windows just the front but about 4-5 inches. i rarely preheat and only for 10 minutes if i do and its still plenty warm in the car and the windows are clear

but ya, i notice fogging is always much worse when there is moisture in the car from rain, damp clothing, kids, etc

 

[Mars]

My S.O. has the car during the week, so I can't try this right now (which is why I am asking). So can I turn on the defrost mode and the foot mode at the same time by just pushing both buttons at once?

 

[GaslessInSeattle]

I believe the power defrost overrides the previous mode selection, going 100% to the windshield. Why the non-power defog mode only allows foot/defog at the same time is beyond me because it makes the feet quite cold in the winter and reduces much needed air flow to the winshield. If there were a mode selection that allowed air to be directed entirely to the windshield that would help, even better if you could also use the fan, all without having climate control on. We would be able to manage windshield condensation much better without loosing range to the climate control.

the technique in the OP is really one of the best ways to minimize range loss, combined with extensive preheating, and if you have it, seat and steering wheel heater.

My S.O. has the car during the week, so I can't try this right now (which is why I am asking). So can I turn on the defrost mode and the foot mode at the same time by just pushing both buttons at once?

 

[dgpcolorado]

My S.O. has the car during the week, so I can't try this right now (which is why I am asking). So can I turn on the defrost mode and the foot mode at the same time by just pushing both buttons at once?

The "foot-defog" technique is selected by pushing the mode button until it shows an arrow at feet plus the defrost symbol. If you then adjust the fan or recirc buttons the CC will go back to using the heater/AC (depending on temperatures).

Besides cold feet, the downside of foot-defog, IME, is that there is little or no airflow at slow speeds, so it doesn't work for defogging. I am waiting for Phil's CC mod to become available to regain full control of the LEAF heater.

 

[Mars]

Yeah, I got that last night. Thanks. And Nissan is dink for not allowing the simple operation of the defrost fan without the rest of the AC being energized. Funny how they got some of the obvious things wrong (the direction of the "shifter" and indeed its very existence, being the most obvious). Nothing like living with an expensive golf cart, making stuff up as you go along. Good that we have each other for backup.

 

[baumgrenze]

We took delivery a year ago, 12/7/11. We had no inside condensate issues until a week ago when we drove the car with wet raincoats on. Now it fogs over and over again as we drive if the outside temperature is 50F or less.

Might there be a problem with AC condensate draining out of the car?

Has anyone found the drain? Is it something that can be checked to see if it is blocked?