Aircon Worries

[highlander]

Hello,

With all this icy/snowy crap going on (i.e. it's pretty bloody cold), my Coupe has a tendency to steam up at the windows.

On my old saloon, I used to put the aircon on and it would take care of the condensation PDQ. However, on the Coupe, all that seems to happen is that the condensation doesn't spread so quickly. At the most extreme, I had to stop the car because I couldn't see properly.

Thing is, the aircon seems to be working because it's blowing cold. What part of the air conditioning / climate control system is it that affects condensation, and what can I do to improve this function on the Coupe?

Cheers
Graeme

[steve_earwig]

I reckon you should start by checking the recirculation flap isn't jammed shut (pull off the pollen filter and check you can see the fan), then there's the drain on the air con to check (I think it's in the coupe club knowledge base) Boot damp inside?

Incidental mine's having a hard time clearing the condensation and I checked my recirc flap earlier - it was open. And that's all it does, I'm sure it used to work

[highlander]

Where's the pollen filter

[steve_earwig]

It's under a plastic cover at the back of the bonnet. Welly did a How To yonks ago... Here viewtopic.php?f=10&t=3870

[highlander]

Much appreciated! Will check the pollen filter out tomorrow (assuming it's not snowing again... )

Incidentally, I have the same screwdriver as Mr. Welton and Mr. MJB - top bit of kit

[steve_earwig]

Will check the pollen filter out tomorrow (assuming it's not snowing again... )

And I'll be pulling off my glove box

You might actually find the pollen filter clogged with crap...

[teamster1975]

You might actually find the pollen filter clogged with crap...

Indeed, clogged pollen filter can cause this. Either that or the receiver/dryer in the aircon needs replacing.

[jansengeorge]

I was just wondering guys, when you turn your heat on and your A/C compressor kicks in acting as a heat pump of sorts, does this have the same effect as using your a/c? What I mean is does it cause your engine to use more gas even though you are using your heat and not the actual a/c unit. Thanks.

[Gary406]

yes if the pump is on you will use more gas,

[lozz]

ive been told,
when the air/con is on the Engine looses, upto 3 Bhp.
and up to 4mpg loss in Mpg,

altho idont have this Worry with mine as it dont have Aircon Anymore,

[Welly]

The a/c cools and dehumidifies only, it cannot produce heat (that's a job for reverse-cycle heat pumps found in office buildings and the like).

If you run the a/c with the car's heating you will just get warm (and very dry) air the a/c will still do the same job that is does in the summer but because the incoming air from outside is so cold, say 2 or 3 deg C, then it has no actual cooling load as such. All that it can do is attract any moisture from the incoming air and help dehumidify steamed-up windows.

Incidentally, if you find you're having a hard time demisting when the outside temp is very low then this is because the a/c will not run below 0deg C ambient - this is to protect the compressor. When the compressor is disabled you fall back to using the outside (heated) fresh air to demist, this takes a little longer that full a/c but because the outside air in winter is pretty 'dry' anyway (all the moisture is lying on the ground) then it's usually quite effective at de-misting.

I don't use my a/c below 10 deg C ambient and have no problems whatsoever with condensation in fact the more you use the a/c for demisting the more likely your are to cause condensation when the car sits idle because you've left it sat there with a nice warm tray of water droplets right near your very cold windscreen......

Welly
HVAC Engineer

[puggy]

Ooooooooo welly old boy what a spiffing explanation

[Doggy]

spiffing

Very posh and dated word meaning excellent, especially as used by upper-class toffs and rugger buggers.

Twickers anyone?

[puggy]

Trust you doggy !! though the only one of those i can be associated with is rugger .

Come on chaps last one in the bath tries to find the soap !!

[rwb]

When it came warmer and very wet early this week I got terrible condensation.
I used the demist button which cleared it, but the condensation kept coming back worse and worse.
(Isn't there a drain that gets blocked?)
So I went back to the old-fashioned method: hot air on full blast and a window ajar. Now it's fine.