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air conditioning as dehumidifier
Posted: Thu Jan 08, 2009 11:47 pm
by rfahren
Has anyone heard of using the air conditioning to dry out recirculating interior air while you're running the heater? We had ice from condensation on all the side windows when we were up north. Running the top vents would partially clear the windows, but at -29 the cold air circulation was just too cold, so we only ran the floor vent, and let it frost over.
Re: air conditioning as dehumidifier
Posted: Fri Jan 09, 2009 12:01 am
by konadog
Yep, do it all the time. Works great. Only I do it with the fresh vent open rather than recirculate, but only because I neve thought to try otherwise. Good idea for the deep cold, for sure. We get as much use outta the A/C in the cold wet weather as when it's hot out, though I sure like it then too!
Re: air conditioning as dehumidifier
Posted: Fri Jan 09, 2009 1:59 am
by FalcoColumbarius
Ditto.
Re: air conditioning as dehumidifier
Posted: Fri Jan 09, 2009 10:32 am
by mararmeisto
If the interior of the car is heavily condensated, start with the A/C and the vent to internal. If the windows aren't wet, just start with the vent to external.
After the windows have cleared, switch the vent over to external. This will allow for fresh air to come inside, and prevent it from becoming stale.
The air conditioner dries the air because it's easier to cool dry air than humid air. It's a good chance to give the A/C a working out through the winter months instead of sitting idle for three or four months (or six, depending on which part of Canada one lives in).
Re: air conditioning as dehumidifier
Posted: Fri Jan 09, 2009 9:05 pm
by rfahren
Thanks. Good to have that confirmed. I haven't tried the A/C in warm-enough weather to know for sure, but it seems as though it turns on when you push the button IN, and off when it's OUT. What confuses me though is that when the dash lights are on, the rear fan button is lit green and turns orange when you push the button to turn it on. In a similar way, the rear window defroster button lights orange when you turn it on. The A/C button, however, is lit orange when it's OUT (and off?), and green when it's IN (and on?). Crossed wires, faulty parallelism, or who the hell cares? Could someone just confirm, please, that IN is on, and OUT is off?
Curious, too, about using cold external air while trying to warm the interior--doesn't that kind of inhibit the effect of the heater?
Re: air conditioning as dehumidifier
Posted: Fri Jan 09, 2009 9:18 pm
by patty
dont think it applies here but i just installed a space heater to be on all the time in this -10 weather of the north, keeps my locks and doors from freezen shut
Re: air conditioning as dehumidifier
Posted: Fri Jan 09, 2009 9:36 pm
by mararmeisto
rfahren wrote:Thanks. Good to have that confirmed. I haven't tried the A/C in warm-enough weather to know for sure, but it seems as though it turns on when you push the button IN, and off when it's OUT. What confuses me though is that when the dash lights are on, the rear fan button is lit green and turns orange when you push the button to turn it on. In a similar way, the rear window defroster button lights orange when you turn it on. The A/C button, however, is lit orange when it's OUT (and off?), and green when it's IN (and on?). Crossed wires, faulty parallelism, or who the hell cares? Could someone just confirm, please, that IN is on, and OUT is off?
Curious, too, about using cold external air while trying to warm the interior--doesn't that kind of inhibit the effect of the heater?
Yes, you are correct: the lighting of this indicator is backward compared to all the others. Pushed in, the system is running; out is off.
No, it doesn't 'inhibit' the effect of the heater, it 'counters' it. However, the heater is more powerful and therefor triumphant. Now, it
is counterintuitive.
Re: air conditioning as dehumidifier
Posted: Sun Jan 11, 2009 10:08 am
by Erebus
Keep in mind that the rear heater and AC is ALWAYS recirculating. Only the front controls have a fresh setting.
Also, it isn't recommended to run the AC when it is too cold (below 0 Celsius is what I've heard) because you will freeze the system.
To defog the whole insides when well below zero, when you've got lots of snow melting, run heating at high fan setting front and back (keep the front on defrost) and crack the windows to let the warm humid air out. Eventually you will have dried the carpets and removed all the moist air.
My Caprice (NAPOS) has the usual American you-are-too-stupid-to-think-for-yourself system. Anytime the control is set to defrost, and the outside temp is above 1C, the AC kicked in. Really nice when it is 3 degrees and the engine is still cold, so you only got colder than outside air. I installed a cutoff switch on the compressor.
Re: air conditioning as dehumidifier
Posted: Sun Jan 11, 2009 11:39 am
by delicat
Spending all my time in the front cab I never paid much attention to the rear AC. So how do you turn it on (rear)? There's no push knob, just this lever moving up and down "cooler"... So by pushing it all the way up you have full AC or full "cold" AC? What about 1/2 way? For cold AC It's probably straight forward but for warm AC at the back?
Thanks!
Re: air conditioning as dehumidifier
Posted: Sun Jan 11, 2009 12:00 pm
by FalcoColumbarius
Although the controls are in the cabin (beside the captain's chair that you sleep in), after all it is the passengers in the cabin who will benefit from it, primarily. The on/off switch is located in that row of four switches to the right of your steering column, along with the rear window defroster, the tailgate release and your fog light switch. The reason it is in the front is for a number of reasons, such as:
- You're the captain, it's your ship ~ if they want A/C they should ask politely anyway.
- You may have people on board that you don't really like and you may want to make life a little clammier for them so that they ask to leave.
- More importantly, the cabin circulation gets rid of things like condensation, for instance, in your rear windscreen.
By and large, it's a control issue.
Falco.
Re: air conditioning as dehumidifier
Posted: Sun Jan 11, 2009 12:07 pm
by delicat
Falco,
The front switch you're talking about, isn't it only to turn the rear fan on? I don't think it activates the rear AC, am I wrong? Reasoning is that when that switch is activated the AC compressor doesn't engage (you don't get on/off increase of rpm...)
I guess to activate the rear AC you still need to push the AC knob on the front heater control so you can't only have rear AC. Sounds like it's a package deal... Or is there a way to only have rear AC?
What I don't get is the rear lever that moves up and down. Isn't this one the rear AC control? If so, why is it graduated instead of on/off? Can you have 1/4, 1/2, 3/4 AC? (or a little bit of AC, a little bit more AC, a lot more AC...) That's how it sounds to me or how I understood it until now!
I've been wrong before... but I'd still like to understand this one!
Cheers,
David
Re: air conditioning as dehumidifier
Posted: Sun Jan 11, 2009 12:36 pm
by Green1
rear a/c and front a/c are on the same switch, but the slider in the back allows you to "turn down" the a/c back there. the switch on the dash for the rear fan is just the fan and is in parallel with the fan switch at the back, either one will enable/disable the fan (and effectively the whole rear system)
Re: air conditioning as dehumidifier
Posted: Sun Jan 11, 2009 12:48 pm
by delicat
Thanks Green1,
That's how I understood the system but never got it confirmed aside from using it myself which I very rarely do (rather roll down my windows kind of guy).
Cheers,