How good is the AC?

bigb

Veteran Member
Joined
Dec 15, 2018
Location
Arizona
TDI
2015 Sportwagon S
Today I used Klima-Cleaner on the evaporator to see if I can freshen it up. It doesn't really smell too bad, it's just when the evap warms a bit there is a hint of a bad smell. Turns out using the Klima-Cleaner on the MK-7 is no easy task. I tried pushing the tube the the blower squirrel cage aiming at the evaporator but it is impossible to know if it actually went to the evap or just curled up in the blower compartment. I didn't feel comfortable letting the contents out with the possibility of flooding the electronics I saw below the squirrel cage when I took a picture in there with my phone. I finally ended up removing the right side console trim and pulled the carpet back and disengaged the drain tube from the tunnel. This is not easy as you have to pull so hard on it you are afraid it will break. Well then there is a 90 right there and the hole is tiny, could not get the application tube to fit that either. So then I pulled the other end of the drain tube off the evaporator housing and stuck the tube in there. To pull that end off you must unplug the air bag harness and cover both ends with something water proof, then pull quite hard to slide the tube off. I then put rags all around the evap and pumped it all in. Then I realized it was not 100% foam, there was liquid in there and I was holding my finger on the drain to keep it in while I summoned my wife to help. She brought me my box of tubing but none was big enough to fit over the evap tube, so I ended up putting the drain tube back on with the other end in a jar, but lost most of the liquid into the rags. If I ever do this again I will use a plastic hose that fits over the evap drain, pump it in then lower the hose and let it drain into a jar. As a side note, although the drain tube is very hard to remove, it re-installs very easily, especially when it is wet.
A short test drive and no real odor noticed, time will tell. Next time I may just use Lysol sprayed into the blower housing.
 

bizzle

Veteran Member
Joined
May 21, 2013
Location
Southern California
TDI
2015 GSW SEL (totaled), 2013 Touareg Executive
Yes, but I have only used the Ozium. I haven't put a Frecious filter in yet, although I've bought one, so I can't say one way or the other about their effectiveness.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
Ahhh, sorry

last year when i fired up the AC for the first time in 2-3 months, it was a bit funky smelling, after replacing the filter with that charcoal one and routinely running the AC the smell went away (hasn't really come back this year either).
 

bizzle

Veteran Member
Joined
May 21, 2013
Location
Southern California
TDI
2015 GSW SEL (totaled), 2013 Touareg Executive
Yeah what happens is the condensation sits and bacteria grows, which causes the smell. Replacing the filter is one fix, running the A/C will also address it as long as you run air through the vent system without any A/C before stopping the vehicle.

Those charcoal filters are intended to remove smells from the air, but this is bacteria that is growing around the filter and I wonder if it's *in* the filter, as well. The activated charcoal is porous and will develop its own bacterial colony, at least that's what we used it for in fish aquariums, but I'm not sure if it's the same bacteria causing the smell.

I never experienced this problem until I moved to the desert. We have 100+ temps with short trips in town so the A/C is always on but only running intermittently. Those nice stop/start cycles are breeding grounds for all sorts of colonies I imagine. I don't know what NH weather is like in that regard, but again I never experienced this growing up in San Diego, and that's only like 100 miles from where I'm at now.
 

bigb

Veteran Member
Joined
Dec 15, 2018
Location
Arizona
TDI
2015 Sportwagon S
Do you guys use a blower cage cover when you change the filter like the factory service manual says to do? I will probably make one, I have a lot of sheet metal in the garage. After seeing how tiny the condensate drain hole is where it 90s into the tunnel I sure don't want to drop anything in there that could clog it up. It's about the size of a BB.






 
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740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
Yeah what happens is the condensation sits and bacteria grows, which causes the smell. Replacing the filter is one fix, running the A/C will also address it as long as you run air through the vent system without any A/C before stopping the vehicle.

Those charcoal filters are intended to remove smells from the air, but this is bacteria that is growing around the filter and I wonder if it's *in* the filter, as well. The activated charcoal is porous and will develop its own bacterial colony, at least that's what we used it for in fish aquariums, but I'm not sure if it's the same bacteria causing the smell.

I never experienced this problem until I moved to the desert. We have 100+ temps with short trips in town so the A/C is always on but only running intermittently. Those nice stop/start cycles are breeding grounds for all sorts of colonies I imagine. I don't know what NH weather is like in that regard, but again I never experienced this growing up in San Diego, and that's only like 100 miles from where I'm at now.

My understanding was that condensation (thus mold/smell) came from the evaporator. Seeing that the filter isn't near/bellow the evaporator, i can't imagine it's dripping on the filter, maybe the moist air from outside is high enough for mold to grow in it?
 

bizzle

Veteran Member
Joined
May 21, 2013
Location
Southern California
TDI
2015 GSW SEL (totaled), 2013 Touareg Executive
I've only ever experienced this in extremely low humidity environments (my county's average relative humidity for June is 26%); it's currently 40% at 9am and 85F. It's forecasted to be 100F and 20% by 1pm and then drop all the way to 11% (with a temp rise to 103F) by 6pm.

I don't think it's the condensation from the evaporator or the outside air. If I had to hypothesize, I'd say it was the temperature difference between a vehicle cooled to mid-70s while the rest of the vehicle's air is circulating through 100F+ degree temperatures that is interfacing at the filter and condensing on the media. It also gets blasted with super-heated air when the car is going through these heat/cool cycles. The cabin air temperature has to be reaching somewhere around 140-160F and that's getting intermittently blasted through the cabin filter, which is also being cooled to mid to sub 70F.

I imagine this dynamic places the filter in a very warm and moist area of the car, which is a perfect breeding ground for smelly things.

I don't necessarily think it's the filter, btw (or rather not *just* the filter). Changing the filter essentials recharges the activated carbon pads and reduces the smell but I would suspect the same heat/cool cycling is causing nasties to grow in the entire vent system. That's why I spray ozium through the venting system. I should say that I don't remember ever pulling a filter and having it smell funky itself. I haven't ever pulled out a moldy filter. I suspect one could buy activated carbon by itself (sold in bulk by amazon or local fish store) and pouches to hold it (also sold by local fish stores) and obtain the same or better result. That said, I've only sprayed about once a year. It's an annoyance but not something that is suffered every day once it's been addressed.
 
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petee_c

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Jun 2, 2014
Location
Heidelberg, Ontario, Canada
TDI
15 Golf TDI, was 06 Jetta TDI, 15 q7 tdi, was 11 Q7 TDI
I've only ever experienced this in extremely low humidity environments .....currently 40% at 9am and 85F.....

If you get dripping when you park the car after the AC is on, you get condensation on the evaporator....

Overtime that is what feeds the mold...

using this dewpoint calculator.... http://www.dpcalc.org/

40% humidity at 85F, the dewpoint is 58F.... I think a health car AC system should be able to put out air in the 40'sF... There is condensation happening....
 

bigb

Veteran Member
Joined
Dec 15, 2018
Location
Arizona
TDI
2015 Sportwagon S
My understanding was that condensation (thus mold/smell) came from the evaporator. Seeing that the filter isn't near/bellow the evaporator, i can't imagine it's dripping on the filter, maybe the moist air from outside is high enough for mold to grow in it?
I've pondered this as well and one thing you have to consider is that the pollen filter can stop the mold spores from reaching the evaporator where they would find a perfect environment to grow.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
I've pondered this as well and one thing you have to consider is that the pollen filter can stop the mold spores from reaching the evaporator where they would find a perfect environment to grow.

Good point, I'll have to sniff the old filter when ever i get around to replacing it.

Our Passat is still on the new filter (if the dealer replaced it in 2017), 39K on it no funky smells either.
 

bigb

Veteran Member
Joined
Dec 15, 2018
Location
Arizona
TDI
2015 Sportwagon S
Reporting back now that it is well over 100 degrees here, the AC is working great, I seldom have it turned all the way cold, usually only if the car is heat soaked and then after it cools down I have to turn it a few clicks warmer and reduce the fan speed. No odors either.:)
 

DevilDogDoc

Member
Joined
Jul 22, 2018
Location
SoCal
TDI
2015 Golf S
I live near Palm Springs, gets pretty warm here. It was 116 * when I left work on Fri. I’ve had mine set to Hot country for a while, seems to cool down faster? I jammed my thermometer in the center vent when I went to the store a little while ago. 100* maybe 10% humidity, vent read 45-46 degrees after driving in town about 45-50 mph. Feels good to me. I crank it full blast when I leave the clinic, after 10-15 minutes I’m on the freeway and I drop it to position 2-3, keeps me icy. I’ll report what the thermometer reads on my drive home tomorrow
 
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