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2014 Leaf 24Kw
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Discussion Starter #1
Hi,

Its been below 5c here for a few days now and I have noticed that anything below 7c give me an issue I never ever noticed in my previous ICE car.

Condensation!

Particularly on the front screen. I have tried all sorts to keep it clear / smear free. On longer runs I have been using the heat only in short burst as it obviously reduces range. I can live with not being cooked but its now starting to really bug me.

Tried nice new chamois leather, Halfords 'special' £3.50 screen wipes and a good old tea towel!

No matter what I use it always looks streaky / smeary until the heater eventually dries it out properly.

Recently [2c] within 15 mins the screen starts misting again [breath?] and you can see the streaks!

Help!
 

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Use a microfiber cloth or 10min AC to the windscreen.
I learned that short bursts of heat is worse to the battery than keep it on at all times on 18c.
Once the temp is close to the set figure the consumption goes down to a few 100's watts, I always use the pre-heat from the mains before setting out.
 

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Leaf 30kWh, Outlander PHEV
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Once you have preheating sorted, keep both AC and heat on (with recirculation). The car consumes around 1kW. If you use demister, the car uses traditional heater rather than heat pump and energy consumption jumps to 4kW.

If more than 2 people travel in the car, the condensation tends to build up. Switch auto which tends to keep heat and uses external air rather than recirculation

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

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2014 Leaf 24Kw
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90 Posts
Discussion Starter #4
From the dash buttons; top left is heat and fan on front screen, bottom left is AC; top right is front screen demist and bottom right is rear screen demist.

From my experiments; it looks like rear demist is not supplied from traction battery and does not seem to reduce range estimates. When pressing the front screen demist (top right) it brings on both the heat and AC on the left which does reduce range estimate. If you subsequently switch off heat and AC on left, the range estimate goes back up but the fan stays on and the top right light stays on - I assume this is just the fan, blowing non heated air at the screen?

127416
 

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Leaf 30kWh, Outlander PHEV
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Demister uses PTC heater

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

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2014 Leaf 24Kw
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Discussion Starter #8
From the POV of max range what is the best strategy if no pre-heat has taken place?
 

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Leaf 30kWh, Outlander PHEV
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From the POV of max range what is the best strategy if no pre-heat has taken place?
Heat and no recirculation. Air on windscreen, fan speed as needed.

- Leaf 30 kWh
Sent from mobile phone so please mind the typos
 

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A PTC is a semi-conductor which when a dc current is applied will either heat up or cool down, depending on the direction of current flow. The vast majority of those tiny hotel cooler 'fridges use a PTC element instead of a traditional compressor to reduce noise and maintenance costs.

To really clean your windscreen use a solution of warm to hot water and methylated spirits. The oils in the plastic used in vehicles breath a cocktail of chemicals into the air which coat the windscreen. The methylated spirits and water solution will cut these (some greasy) particles and leave your screen sparkling and less prone to these deposits until the next time. Use a traditional chamois leather and dry with a micro-fibre cloth. If you are a smoker then there is no hope for you.:(
 

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2014 Leaf 24Kw
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Discussion Starter #11
Thanks @Barfly - assume Isopropyl Alcohol would do a similar job? That said I have a 500ml bottle of meths, although it is white [defo not white spirit, says meths on bottle] which I bought last time I was at DIY centre!

Might give that a shot today. Thankfully temp has gone up to 7c. Not sure if that's a good thing...

 

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my strategy is this:

press front demist on
press recirculation on
set temp to 18
turn down fan speed to 1 or 2 once clear
dont press any other buttons

carry on with no misty screen
 

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Nissan Leaf 24 Tekna '64 reg
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A really clean windscreen is key. I clean the inside of my windscreen every autumn to ensure good visibility during winter.

I got an extending arm thing for cleaning inside of windscreen, then just use regular supermarket window cleaner with a few kitchen towels. If your screen is really dirty, you may need to repeat cleaning many times.

As for driving, I leave the car in auto, 21-22c. No problem with condensation except when raining heavily with 3 wet people inside.

I find recirculate, heater + AC drains the range too much. Yes, it will solve condensation and no outside pollution, but the constant battery drain adds up to a lot over whole of the journey. eg. constant 1kW over 30 minutes vs 4kW for 2 minutes.
 

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2011 Leaf with Muxsan 17.6kWh battery, curt tow hitch fitted for bikes or buzz rack P10
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if you have the 2011-2013 leaf. which only has a 5kw ptc element there are wiring harnesses made by leafma in Norway. they put an inline resistor to fool the temp sensor into thinking the car is already warm. Why? because then you can use the blowers on the screen without drawing power through the lossy ptc heater. When coupled with heater seats (£25 on ebay) you have a more efficient solution than heating the whole car. This wiring harness has 3 settings on off and 40%. I think it is because he using a hydronics diesel heater on the same coolant loop rated at 3kw so by running the ptc at 2kw and supplementing the rest using the eberspacher 3kw heater he doesn't over spec the design.

I bought one to do the same thing but my extender battery and heated seats has meant I've made it though winter without having to un-zero my emissions.

The condensation is terrible though. I like Barfly's comment, cleaning must help some and its cheap to do. Also there are those microwaveable condensing gadgets.
 

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I actually have 2 chamois leathers I use on the car, one specifically for windows and I do not use it on anything else. It makes a huge difference. :D
 

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A PTC is a semi-conductor which when a dc current is applied will either heat up or cool down, depending on the direction of current flow. The vast majority of those tiny hotel cooler 'fridges use a PTC element instead of a traditional compressor to reduce noise and maintenance costs.
Mixed up with a peltier/TEC (thermo electric cooler). They can heat or cool depending on direction of current flow. PTC heaters can only heat. But you are correct that most if not all of those tiny fridges and beer coolers use peltiers.

PTC means positve temperature coefficient. In this case its a PTC heater, the hotter it gets the more it resists current flow so its a safe self regulating heater.
 

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Jon- You are right of course, the Peltier effect is what I meant - PTC is Positive Temperature Coefficient. We used to use them in the de-guassing coil circuits of the old CRT TV sets to de-magnetise the screens at every switch on to maintain colour purity. A PTC presents a virtual short-circuit at switch-on then as the current flows the resistance increases exponentially to limit the current to a small residual flow.

Dear oh dear, don't get old, I constantly get my acronyms mixed up. I will edit my original post-thanks you for pointing out this error. Now the site won't let me edit this...very frustrating.
 
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