Preconditioning fogs up the windows

[londiniumperson]

A couple of points, my car in the UK in the current weather conditions has always required 20+ mins to clear all of the windows, there's no way it can clear it in 10 mins.
Also have you opened & pointed each of the side dash vents to point up and out to the side windows because unless you have then there is no chance the side windows will clear for a very long time?

[ZeroEmissionRequiem]

A couple of points, my car in the UK in the current weather conditions has always required 20+ mins to clear all of the windows, there's no way it can clear it in 10 mins.

I'm not trying to clear the windows of anything with preconditioning because they're already clear. What I have been trying to say is that the windows are perfectly clear BEFORE preconditioning; they fog up on the inside DURING said process.

[Fed]

Was going to say… if you have fogged windows on the inside beforehand then you have a bigger issue.

[ramesses]

I experinced similar situation as ZeroEmissionRequiem. I stopped at chager, start charging, start preheating up and went shopping (about 20 min.). When I came back to my e it was completely foggy from inside (all the windows even roof one). I had to turn on fast windshield defrost and waited for dry up.

[londiniumperson]

I'm not trying to clear the windows of anything with preconditioning because they're already clear. What I have been trying to say is that the windows are perfectly clear BEFORE preconditioning; they fog up on the inside DURING said process.

I see, I had misunderstood.

I re-read through all the posts on this topic and can’t see anywhere you’ve said if had you set the preconditioning to a colder/normal/warmer temperature with auto defrost on/off. Which settings have you tried?

On one of your posts you said that you ran at max heat with A/C before preconditioning later. What was your thoughts behind this?

[EEEE]

The air conditioning specifically, even with heat, will help to dry the cabin air. The warm air (heated, with moisture), will then condense on the AC evaporator , and the moisture will drip out of the AC drain under the car. You can action this from the control panel.

When using the preheating in cold weather, the AC does not activate (The simplistic test is the cabin temp does not need cooling), so there is no drying of the air via AC operation, so it tends to just fog up the car. In most UK mornings, there isn't much benefit to preheating. I'm on the edge of a housing estate, complete with a stream and fields all around and lots of trees and hedgerows (it's not as idyllic as it sounds), but there is almost always lots of moisture in the air, and preheating just dumps it into the car as per the OPs picture. Even 30 mins sometimes is not enough to clear it. Mornings are worse. If i preheat at lunch time say, when the morning dew is gone, the problem is very much reduced.

That is not to say the preheat cannot use AC. When set to 'colder' on the app, in the height of summer, the car will be cooled via AC, but that doesn't apply when the ambient temperature/cabin temperature is low. That is my observation at least.

Cold and crisp mornings (where there is no external moisture/vapour), preheating is fine, because there is no external moisture being dumped into the car (or very little).

I'm not sure where the AC drain actually exits the bottom of the car, it might be worth checking its not clogged as this could lead to moisture in the airbox. If its like the scuttle panel drain, it may be too small and get clogged easily - that said AC condensate is normally very pure and clean and shouldn't clog (unless its algae/slime).

The prelude AC drain is a decent 1cm wide pipe, with a vacuum/diffuser thing on the end (I assume in motion to help suck moisture out of the cabin airbox where moisture may remain).

[ZeroEmissionRequiem]

I've narrowed down the cause of this issue btw; it tends to happen after visiting a self-service car wash. While washing the windscreen and the area underneath it, it would appear enough water makes it's way to the air intake, and results in a slightly damp cabin air filter. Once I take the cabin air filter out of the car and let it dry indoors overnight, all's well. I've never had this kind of an issue with any of my previous cars.

As I typically use the pressure washer on the windscreen from the LHD side, I'll try to do it from the RHD side next time. Might be the angle or something.

[Isotope Toast]

@ZeroEmissionRequiem: where can one find this cabin air filter you speak of? I have this exact same problem and as it's incredibly humid where I live, I'd like to try drying it out.

[ZeroEmissionRequiem]

Honda - owner's manuals

Page 622-624 on the 21YM manual for the e.

Takes like a minute to replace, so no sense in paying a dealership to do it...

One silly thing about the air filter; when air recirculation is on, the filter is exposed to the glovebox, which is of course open at the top. I've twice managed to get a paper towel (which was on top of everything else in the glovebox) somehow sucked into the filter. The paper towel was damp, so clearly water somehow gets all the way to the filter.

Here's how it looks when going from normal to recirculation:

filters.mp4

(839.65 KiB) Downloaded 20 times

[Isotope Toast]

@ZeroEmissionRequiem: great - thanks for the detailed answer!