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Old 25th April 2008, 15:49   #16
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Originally Posted by srishiva View Post
I have heard its 10 ml per minute on average.

Bangalore currently is like 33 degrees with 30% humidity and cool winds (winds are never warmer here anyway).

that translates to approx Rs27 per hour for a airconditioned box in the middle of no where ( its definetly a bargain !! )

whats with this GLOBAL WARMING/ POLLUTION etc etc? what additional pollution will this cause apart from normal driving ???
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Old 26th April 2008, 11:56   #17
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Way back in 1990, when the power situation in Delhi was very grim with powercuts ranging from 8 to 12 hrs at a stretch, I on one June night with my wife and 16 month old son slept in my amby with the engine running and the AC on.

I was fully aware of the CO poisoning hence had lowered my window by 1/2 an inch...

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Few cases of deaths has been reported due to keeping the A/c on with idling engine for long hours.

Last edited by gd1418 : 26th April 2008 at 11:59.
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Old 26th April 2008, 15:12   #18
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If you want to use AC run engine and switch ac ON.

Best is to park in a nice shade, lower all windows and adapt how much ever to the heat or find a cool shaded bench while your car fights the sun, save fuel and nature.
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Old 26th April 2008, 20:14   #19
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Well maruti says if it is necessary to keep the engine and the ac on - while the car is stationary - then to keep the blower speed HIGH and the ventilation mode to fresh air.
If parked in a "safe" place do keep your hood open , really helps the engine heat buildup issue
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Old 26th April 2008, 21:14   #20
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If its my family that is waiting in the car then I leave them with the AC on.
Such instances are very rarely more than 2 or 3 minutes long.

If I am waiting alone for someone, the car is switched OFF, completely OFF even the ICE. Depending on how hot it is I might remain in the car or at some nearby tea shop or stroll down the pavement.

IMHO The car or bike is a very good friend.
I am incapable of doing stuff that is in my opinion an act of cruelty on her.

My wife feels I treat my car and bike better than I treat people.
and I am proud that she is not wrong.
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Old 27th April 2008, 01:51   #21
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Yes it would be really intresting if someone could point out what should be the consumption of fuel while engine is kept running with a/c on .Guesstimate s are available a plenty any GURU who really know s what is the amount of fuel consumed with and idling engine it must be surely different for bigger engine cars (read accord civic camry) than smaller engine car s (read santro spark swift) .
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Old 27th April 2008, 19:36   #22
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The idling RPM for my NHC is 800.
The RPM at 80 kmph in 5th gear is 2500 and this is the RPM range (~2200 to 2700) in which the iDSI engine is in it's most efficient mode (from fuel consumption as well as pollution point of view).

Hence, it's very obvious that idling is not the best situation for the engine.

If you want to use A/C in a stationary car, ideally you should run the engine in neutral and keep the accelrator pressed such that the engine RPM is maintained in ~2200 to ~2700 range. This will minimize pollution and will be less streneous for the engine. Of course FE will take a slight hit but that will still be more eonomical compared to the long term engine strain and pollution at the regular idling RPM (~800).

Last edited by anandpadhye : 27th April 2008 at 19:37.
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Old 27th April 2008, 20:43   #23
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Quote:
Originally Posted by anandpadhye View Post
The idling RPM for my NHC is 800.
The RPM at 80 kmph in 5th gear is 2500 and this is the RPM range (~2200 to 2700) in which the iDSI engine is in it's most efficient mode (from fuel consumption as well as pollution point of view).

Hence, it's very obvious that idling is not the best situation for the engine.

If you want to use A/C in a stationary car, ideally you should run the engine in neutral and keep the accelerator pressed such that the engine RPM is maintained in ~2200 to ~2700 range. This will minimize pollution and will be less streneous for the engine. Of course FE will take a slight hit but that will still be more economical compared to the long term engine strain and pollution at the regular idling RPM (~800).
huh!! huh huh huh!! are you sure about this???

ac comp load vs moving a ton of sheet metal at 80 kmph and wind resistance,rolling resistance etc. have you tried a PUC machine, try idle and 2000 rpm you will see the diff in so called polution!!

Yes idle might not be most efficient at cooling, since there in do draft of cool air on the car when moving, to cool the engine/radiator or the body, but hey its much better than 2000 rpms, yup at 2000 rpm ac might cool a lil faster due to higher rpm of compressor but no way efficient.

Last edited by Jaggu : 27th April 2008 at 20:56.
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Old 27th April 2008, 22:36   #24
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I am talking about combustion efficiency.
FE is irrelevant here as distance travelled is zero.

But yes, it's good idea to check PUC figures at 800 RPM and 2500 RPM.
I will do that at the next available opportunity - just out of curiocity.
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Old 27th April 2008, 22:47   #25
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dont bother, it will be higher tried it already
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Old 27th April 2008, 23:21   #26
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great. but, which is higher?
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Old 28th April 2008, 11:51   #27
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Quote:
Originally Posted by anandpadhye View Post
Yes, if wait time is more, why wait inside the car?
Kindly be considerate to mother nature as well.
An idling engine with A/C on is definately going to cause a lot of pollution.

The A/C is driven by the engine through a magnetic clutch. So even if engine is off, this clutch will be engaged as long as your battery has the charge, though the A/C compressor will not run as the prime mover (the engine) is off. Hence, if you need A/C to do it's job, you need the engine running.
Firstly, when your engine is idling, it takes in richer mixture of fuel.

Secondly, if you switch off your engine , then only your blower fan works. Nothing else. Compressor is switched off. So it's better, either you open your windows or go out of your car and chill out/hang out somewhere or sit in yiur car and enjoy the sauna.

Cheers
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Old 1st May 2008, 13:09   #28
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The Heat in delhi is unbearable, the AC in my zen just doenst cool any help guys?
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Old 1st May 2008, 18:29   #29
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Originally Posted by Kaizer Sozay View Post
The Heat in delhi is unbearable, the AC in my zen just doenst cool any help guys?
Did you get the AC serviced ? If not get it done, should make things better. Also, get the gas topped up etc.

Also, you could get window film/front windscreen film installed.

There is a ton of info on Front windscreen and window films on the forum, try searching for it.
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Old 2nd May 2008, 00:39   #30
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Quote:
Originally Posted by Kaizer Sozay View Post
The Heat in delhi is unbearable, the AC in my zen just doenst cool any help guys?
Get it service properly. And make sure when it is serviced they take out the blower & cooling coil from behind the dashboard (dashboard will have to be taken out) and clean them properly with chemical & water to remove all the dirt & grime.

Some pics of this process are available on one of my car's threads. Search for it if you want.
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