[Live To Jive]

Originally Posted by sgiitk

I will advise the following:

1. In wet conditions or to defrost the windscreen the fresh setting is necessary.
2. If you want to use the AC and are finding it a bit too cool, then switching to fresh is another way of reducing the cooling.
3. When you park the car do remember to switch the vent to recirc (I am talking of manual/wired controls) and not electronic controls.

My +1 to that

Originally Posted by GTO

I have stopped using the "fresh air" mode altogether. You'll find my cars running only in recirculation mode, except for long highway drives where we'll switch to "fresh air" for 10 - 15 minutes (lighten up the insides). Unsurprisingly, the air-conditioner is a lot more effective when running in recirculation mode.

I do the same and this is the best if using the AC. However Gansan is not using the AC

Gansan : If you like driving around in "fresh air" mode, well...do just that. Don't worry about the cooling coil. What the SA told you is akin to "if you use the brakes, you will need to replace your pads one day"

Correct. Anyway when you service your AC you have to clean the coil and vents. If you open the windows the whole cabin will get dirty unless you live in a village where the air is clean. If fresh air mode was bad, why do manufacturers provide it?

[Gansan]

Originally Posted by govigov

If i need fresh air in the long run, i just crack open the windows a bit,

Originally Posted by Mpower

Personally, what I do is crack the driver side and the diagonally opposite rear window

Why do you guys have to do that? Whay not just open them a crack instead?

Sorry, could not resist that! (Wisecrack?).

Originally Posted by Mpower

Hi-end cars have what is called cabin air filter (or pollen) filter which will capture all the dust etc in fresh air mode. (so cooling coil is totally protected)

How I wish my car had it! Is there any way to install one?

Originally Posted by Live To Jive

If fresh air mode was bad, why do manufacturers provide it?

My thought exactly.

[gavinimurthy]

If your car is equipped with ACC , it is prudent to use auto mode. It automatically lets in fresh air periodically. If you keenly observe, you willl find that when the difference in temperature (outside vs set temperature) is high, the ACC automatically selects recirculation mode. Once the cabin is cooled, it switches on to to fresh air mode.

While crossing highly polluted areas you can 'force' the ACC to recirculation mode. Once you force it, it remains there till you reset it. To bring back the automatic function turn the related knob to off position briefly and bring back to auto position.

It is not wise to drive always in recirculation mode with windows closed. That will affect your health in the long run. Don't worry about dust accumulation etc and use the fresh air mode atleast for 10 minutes in an hour when you are on a long drive, if your car has manual A.C.

The car AC too needs periodical servicing. There is no way you can avoid it without loosing the effficiency. Better to get it serviced atleast once in an year.

Murthy

[m-hawk]

Originally Posted by suneet_ag

In my car (Verna) whenever you switch on the Auto AC mode the fresh air mode is automatically switched on. In fact you cannot keep the Auto AC mode with recirculation also on. I usually drive in the recirculation mode as during traffic the fumes start getting inside the cabin and that is not a pleaseant feeling. The auto mode switches off whenever i am in the recirculation mode.

Anybody else has similar settings?

I have noticed this on most of Hyundai car s . The ones with auto climate have this trait whenever the A/C is switched on it in automatic mode the fresh air is always on I have to alway s switch on the circulatory mode but I suppose if one drives for sometime and sufficient fresh air is drawn the car wiill switch automatically to Rec mode but never tried it !! is anybody aware of a way to set it on Rec mode .

[myavu]

Originally Posted by gavinimurthy

If your car is equipped with ACC , it is prudent to use auto mode. It automatically lets in fresh air periodically. If you keenly observe, you willl find that when the difference in temperature (outside vs set temperature) is high, the ACC automatically selects recirculation mode. Once the cabin is cooled, it switches on to to fresh air mode....

It is not wise to drive always in recirculation mode with windows closed. That will affect your health in the long run. Don't worry about dust accumulation etc and use the fresh air mode atleast for 10 minutes in an hour when you are on a long drive, if your car has manual A.C.

The car AC too needs periodical servicing. There is no way you can avoid it without loosing the effficiency. Better to get it serviced atleast once in an year.

Murthy

I fully agree with you. I am following this for last 7 years (800, UVA & Beat).

It should be like that.

Originally Posted by m-hawk

I have noticed this on most of Hyundai car s . The ones with auto climate have this trait whenever the A/C is switched on it in automatic mode the fresh air is always on I have to alway s switch on the circulatory mode but I suppose if one drives for sometime and sufficient fresh air is drawn the car wiill switch automatically to Rec mode but never tried it !! is anybody aware of a way to set it on Rec mode .

It all depends upon the temperature you set in the ACC. I use to do that (not in winters - manufacture clearly mention that in manual). When I start the ACC in Beat, it starts with Fresh Air mode and the blower will be in the higher speed. Once the set temperature is achieved the blower speed comes down and the recirculation mode is turned on.

Cheers!

Vinu

[esteem_lover]

I had gone one step beyond and actually sealed the fresh air vent, so even if the knob is put in fresh air by mistake, my CC is saved.

[Seeler_Rebeiro]

"I assume your AC in not in the cooling mode with only the blower on; why put the extra load on the engine?
Correct me if I am wrong, but is it not the compressor (AC) that puts the load on the engine, and not the fan! AFAIK the fan speed also has no bearing to the load on the engine!"

Well electricals do put incremental load on the engine. As electrical load (fan, sound system etc) gets added, the alternator generates "back emf", which requires the prime mover (here the engine) to work harder, to ensure the alternator continues to provide the power at same voltage/frequency.

[VW2010]

I feel during the months of Dec and Jan, closed vents kind of create a funny smell due to the humidity etc. Once a while its perfectly needed to let fresh air in specially if its a bit sunny in the day. Cold and dark are perfect friends for fungus. By at least letting in some warm air we can avoid it. Just like maintaining ones camera lens. Just expose to light and never store it inside a bag during these humid seasons

[fuel_addict]

Originally Posted by m-hawk

I have noticed this on most of Hyundai car s . The ones with auto climate have this trait whenever the A/C is switched on it in automatic mode the fresh air is always on I have to alway s switch on the circulatory mode but I suppose if one drives for sometime and sufficient fresh air is drawn the car wiill switch automatically to Rec mode but never tried it !! is anybody aware of a way to set it on Rec mode .

I believe this setting varies from car to car. In my Swift like I said earlier, I have to manually choose recirc. option in the Auto AC mode (same as Hyundai cars as you mentioned). I have seen two modes in the Swift's ACC - Full Auto AC and Auto AC. Full Auto AC toggles between recirc. and fresh air. Auto AC will stay in the mode chosen - either fresh air or recirc.

In my Altis however, it'll select the mode you have preset - either recirc. or fresh air (set to recirc. by dafault in my car). No toggling takes place once the Auto AC is ON.

[gpa]

Originally Posted by Gansan

Thanks,everyone! I have decided to play safe and use the vent only in absolutely unavoidable conditions. I will roll down the window or take breaks on the highway instead.

I hope no damage has resulted already! Considering the car has only done 8000 KM so far, and must have run on ac for at least half of it, may be it has not. As EL remarked, premature expenses on items of safety is one thing; the same on comfort/cosmetic items will hurt me a lot.

Is there any way to assess for any clogging without opening up? Will measuring the air temperature at the ac outlet help? Both the cooling and throw seem to be unchanged till now.

Gansan,

Just read this thread of yours now and would like to add my bit to it. My Alto has covered 50k kms now and I disconnected the re-circulating flap when the car was brand new after the second service at 5k kms. Since then whenever I need fresh air with the a/c on I simply roll down my window for a few mins when I'm on an open stretch of road.

Has this helped over the 50k kms? Yes, it has. There is no drop in blower speed at 50k kms since the blower is free from leaves, twigs and dust that would have otherwise slipped in if the re-circulation flap was left open. The cooling had dropped a bit, but then that was down to the low levels of gas in the system which I recharged and not due to dust clogging the coils.

When I was at the recent 50k kms service last week, the a/c mechanic who recharged the gas of the car sat inside and inserted a temperature probe to check the compressor cut-off temperature pointed out that the re-circ cable was not working and that's when I explained to him my logic behind disconnecting it. He agreed that it was a good idea since I wouldn't be spending on cleaning of cooling coils.

Use a home vacuum cleaner to suck out dust from the internal intake slats located underneath the dashboard near the passenger side foot-well once in a while as that will ensure the air you breathe is free of dust. It also helps to keep the areas underneath the dashboard on the LHS free of dust as that will be sucked in when you use the blower on a high speed in re-circ mode.

Hope this helps

Cheers,
gpa

[vigsom]

I agree with the techniques of EL and gpa.

Fouling of the evaporator coil is an issue associated with operation on fresh air mode ; unless the car has a cabin air filter.

I disconnected the batt of my Corolla H4 since I was out of town for 2 weeks ; when I return,connect batt and start the car ac,I see a whole lot of dust being blown ; was wondering where so much muck came from and then saw that the recirculation button was not pressed ; pressed that button immediately

I shut offf the compressor,ran the blower at full speed for a few minutes and all dust was gone.

After that,I checked the mesh that I had provided where the cabin air filter should be ; and the mesh had luckily blocked twigs,rat droppings,small gulmohar type leaves, etc.

Lucky ; shudder to think what would have happened if the mesh had not been there.

Moral - block the muck out ; either through forced circulation+use of the window OR use a proper cabin air filter

[Aroy]

I always drive with fan on in recirculating mode, AC or no AC. I like the air flow hitting my face.

Once in a while I switch the fresh air on, and a whole lot of dust is blown in for some time.

The AC fresh air inlet is in the engine compartment, so you are getting air which has passed through the engine bay, and may not be all that fresh. The only utility of the fresh air inlet is to mix the outside air with the cabin air. You might as well as use the window for it.

It is only while using the heater, that fresh air input is required. You are advised not to use the heater in recirculating mode.

Regarding demisting, I have found that AC (in summer and heater in winter) + recirculating air, demists faster than using fresh air, which is moist and can mist the inner side of the windshield (normally the outside mists).

[gpa]

Originally Posted by Aroy

The AC fresh air inlet is in the engine compartment, so you are getting air which has passed through the engine bay, and may not be all that fresh.

A small correction, the inlet for the a/c in cars is not inside the engine compartment, rather it is housed outside under the plastic flap where the wipers are located. Look closely and you'll see rows of slats in the plastic covering where the wipers are bolted on, these are the intake slats for the a/c

[Gansan]

I have been using only recirculation mode for the past year. Except on the highways where I switch to fresh air mode every one hour, when I feel the road is dust free.

[Lobogris]

I mostly keep my system in the fresh air mode, mostly on the blower as the outside air helps cool the cabin and reduces stuffiness. If the temp is very hot outside (more than 43 C), I will keep in on recycle. When passing through a dusty area, I switch on the re-circulation mode briefly until the air is clear again. I think people are too worried about this issue. After all when we walk around, we breathe in the outside air, when we are in a non air conditioned office or home, we breathe in the same air. If we have to pass through some dusty unpaved road or an area where it stinks, that is one thing. On normal drives the outside air is fine and I avoid excessive use of ac.