AC defroster - Why
12-10-2013, 07:35 PM
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AC defroster - Why
I've been wondering this for a while and I keep seeing threads on turning off the automatic AC when the defroster is set. My question is why did Honda choose to not give the user the option to turn the ac off when the defroster is on? It seems like a very deliberate decision on their part.
12-10-2013, 07:41 PM
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It might have something to do with the fact that the average schmuck in a damp climate might not realize that the AC will aid in defogging, so if they happened to have it disabled and got in an accident because they couldn't figure out how to defog the windscreen, it's one more way the car manufacturer could be blamed.
That's a long shot but I honestly don't have any better ideas. It seems trivial I know.
That's a long shot but I honestly don't have any better ideas. It seems trivial I know.
12-10-2013, 10:00 PM
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Thats pretty much it. A little humidity goes a long way. Lots of customers bitch over time that defrosters don't work and don't realize compressor needs to be on to do it quickly. They made it idiot proof to keep people happy. On other cars with ND screens you have to take several steps to disable the compressor; it always comes on at first automatically.
Its really not a big deal. Its a good idea to run the compressor every few weeks to keep the seals tight and lubricated. It does not appreciably decrease fuel economy or reduce power.
12-11-2013, 03:45 AM
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When the AC is on (and the recirc button) in conjunction with the heat, you will get rapid dehumidification in the interior. Any moisture in the air freezes instantly when passed through the AC core, and super dry air comes out to the windshield and interior.
Lets say you get in the car after running across the mall parking lot in the rain. The water on your clothes will evaporate and steam up the windows.
If you run the heat, with AC, and recirc, you will be very dry in no time.
Do the reprogram that was posted, takes 10 seconds. When finished, the AC will still come on with the defroster, but now you can turn it off. We call it the AC mod.
Next time you have steam/fog on the inside of the car, try the heat and defrost with no AC. Then hit the AC button and watch how fast the steam disappears.
Lets say you get in the car after running across the mall parking lot in the rain. The water on your clothes will evaporate and steam up the windows.
If you run the heat, with AC, and recirc, you will be very dry in no time.
Do the reprogram that was posted, takes 10 seconds. When finished, the AC will still come on with the defroster, but now you can turn it off. We call it the AC mod.
Next time you have steam/fog on the inside of the car, try the heat and defrost with no AC. Then hit the AC button and watch how fast the steam disappears.
12-11-2013, 05:46 AM
#6
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When the AC is on (and the recirc button) in conjunction with the heat, you will get rapid dehumidification in the interior. Any moisture in the air freezes instantly when passed through the AC core, and super dry air comes out to the windshield and interior.
Lets say you get in the car after running across the mall parking lot in the rain. The water on your clothes will evaporate and steam up the windows.
If you run the heat, with AC, and recirc, you will be very dry in no time.
Do the reprogram that was posted, takes 10 seconds. When finished, the AC will still come on with the defroster, but now you can turn it off. We call it the AC mod.
Next time you have steam/fog on the inside of the car, try the heat and defrost with no AC. Then hit the AC button and watch how fast the steam disappears.
Lets say you get in the car after running across the mall parking lot in the rain. The water on your clothes will evaporate and steam up the windows.
If you run the heat, with AC, and recirc, you will be very dry in no time.
Do the reprogram that was posted, takes 10 seconds. When finished, the AC will still come on with the defroster, but now you can turn it off. We call it the AC mod.
Next time you have steam/fog on the inside of the car, try the heat and defrost with no AC. Then hit the AC button and watch how fast the steam disappears.
12-11-2013, 08:34 AM
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12-11-2013, 08:43 AM
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Thanks guys. That is what I figured I was just curious because it recently snowed in my area and I ran out to my car before a drive to melt off all of the ice on the windshield because I misplaced my ice scraper 
I figured that the process would be faster if the air wasn't cooled by the ac first then flowed through the heater core. Thinking about it now though, I think the typical AC blows at 50F ish and it was like 30 outside so I don't know if it would have made a difference. Any thoughts?
I am definitely going to try the mod this weekend thanks again.
I figured that the process would be faster if the air wasn't cooled by the ac first then flowed through the heater core. Thinking about it now though, I think the typical AC blows at 50F ish and it was like 30 outside so I don't know if it would have made a difference. Any thoughts? I am definitely going to try the mod this weekend thanks again.
