Go Back   Team-BHP > Under the Hood > Technical Stuff


Reply
 
Thread Tools Search this Thread
Old 12th September 2008, 12:04   #31
BHPian
 
Shashank.A's Avatar
 
Join Date: Sep 2007
Location: New Delhi
Posts: 479
Thanked: Once
Default

Quote:
Originally Posted by Path_Finder View Post
Very True - The difference is very much noticabe - with smaller cars switiching off the a/c is specificaly useful while overtaking to get that extra thrust.
With the AC on I was not able to push it beyond 120, but after I put it off, I was able to drag it to 138 on the fourth Gear itself.

And yes, its does feel like a rocket booster has been activated when you switch the AC off.

There is a feeling in the Esteem as well, but its not as noticeable as in Alto.
Shashank.A is offline   Reply With Quote
Old 12th September 2008, 12:21   #32
BHPian
 
Path_Finder's Avatar
 
Join Date: Jul 2008
Location: Bangalore
Posts: 623
Thanked: 5 Times
Default

Quote:
Originally Posted by Shashank.A View Post
With the AC on I was not able to push it beyond 120, but after I put it off, I was able to drag it to 138 on the fourth Gear itself.

And yes, its does feel like a rocket booster has been activated when you switch the AC off.

There is a feeling in the Esteem as well, but its not as noticeable as in Alto.
Folks, to clarify - my observation is more on M800, earlier Zen. I have not driven the Alto - so not sure how noticebale it is.
Path_Finder is offline   Reply With Quote
Old 12th September 2008, 12:22   #33
Senior - BHPian
 
vnabhi's Avatar
 
Join Date: May 2007
Location: DC -> DC
Posts: 5,272
Thanked: 1,236 Times
Default

Quote:
Originally Posted by Path_Finder View Post
Coming to Nitin’s usage queries - I would recommend not doing the manual off/on very frequently. This is not good for compressor which is why your home a/c stabilizer usually has a 1 minute cut-off.
............. But it does make some difference in city driving – but do give at least 2 minute gap in between operating the switch.
I disagree with this bit, based on my experience.
I used to give a 2 min gap between switch on and switch off in my WagonR, until I saw a pal in an Accent switching it on and off in seconds, especially in 2nd gear to get a boost in pickup. I too started practising the same for the past 6 years on my WagonR, moreso to prevent autorickshaws from overtaking me when there is a gap in the bumper to bumper traffic. Touch wood, my AC is fine for the past 7 years, and i've not even changed the gas!
So to 2 or 3 minute rule applies only to home ACs, not car ACs.
vnabhi is offline   Reply With Quote
Old 12th September 2008, 23:57   #34
BHPian
 
viper_711's Avatar
 
Join Date: Jan 2008
Location: Bangalore
Posts: 346
Thanked: 55 Times
Default

Quote:
Originally Posted by cooldude1988765 View Post
I am sure any car equipped with an ac/heater will have a thermostat. The knob with the blue and red markings is the thermostat.
That is so not cool dude! (sorry, couldn't resist that!)
The knob you mention is not the thermostat. Please read the posts before your post and read the one by merve extreme a few post after your post.
viper_711 is offline   Reply With Quote
Old 13th September 2008, 18:29   #35
BHPian
 
teknophobia's Avatar
 
Join Date: Mar 2008
Location: Ahmedabad
Posts: 319
Thanked: 22 Times
Default

On my car you can easily make out that the compressor is switching on and off, there is an audible click. In idle, the RPM drops and rises slightly as the compressor goes on and off.
teknophobia is offline   Reply With Quote
Old 13th September 2008, 18:47   #36
BHPian
 
Join Date: Feb 2007
Location: Pune
Posts: 144
Thanked: 0 Times
Default

Good to know that there's no such thing as the 2 minute rule! Even I like using the AC button as the Nitro booster, especially when I badly need some power and don't want to strain the engine too much (with the AC and the acceleration). Even I was worried about the health of my compressor, and the ill effects of frequent ON/OFFs. Good to know about the 7 year-WagonR guy.
amu1983 is offline   Reply With Quote
Old 13th September 2008, 19:17   #37
BHPian
 
Join Date: Mar 2008
Location: Chennai
Posts: 103
Thanked: Once
Default

My 2 cents worth. I own a Getz Prime 1.3 GLS purchased in April 2008. I have been fiddling around with the AC settings & trying to find out what difference it gives in my mileage. My observations are given below:

1) When the rotary knob (which I think is the thermostat) is fully towards the blue, in city traffic, I used to get around 9 - 10 kmpl. AC was used 90% of the time. I used to switch off the AC once in a while when I felt too cold.

2) I then moved the rotary knob half-way through (between the red & blue markings). I also inflated my tyres 10% more (instead of the recommended 30 psi, I inflated it to 33 psi). My mileage went up to 10 - 11 kmpl.

3) Now, I'm presently running without using the AC. I will know my exact mileage only when I tank up the next time, which should be sometime next week. But, I can tell for sure that my mileage has gone up by about 35%. I haven't checked my tyre pressure yet but it's definitely at least 30 psi.

All the above runs were fully city driving only.

My car is due for 2nd service in about a month's time. After service, I expect mileage to increase by 10 - 20%.

Krishnan
akrish01 is offline   Reply With Quote
Old 13th September 2008, 20:23   #38
BHPian
 
Join Date: Mar 2008
Location: Chennai
Posts: 103
Thanked: Once
Default

More observations from me.

I feel that my mileage has gone up by at least about 30% when I drive without the AC as reported earlier. The main reason for this, I feel, is because I'm able to shift into higher gears (3rd gear onwards) quicker than when I'm driving with the AC on. I'm a very gentle driver - I accelerate & decelerate gently, using 2000 rpm as my guideline to shift from gear to gear.

On the highway, I think I was getting about 16 - 17 kmpl with the AC on - never tried it without the AC yet. I achieved this figure by not going over 80 kmph.

Krishnan
akrish01 is offline   Reply With Quote
Old 15th September 2008, 11:28   #39
BHPian
 
cyclops's Avatar
 
Join Date: Mar 2008
Location: Pune
Posts: 297
Thanked: 9 Times
Default

Quote:
Originally Posted by viper_711 View Post
Dude! Waiting for your observations!
hey viper.. sorry somehow missed this thread.
yes, my observation was as per your anticipation..

but i guess merve's post has made the concept clear for us.
the blue-red knob controls the thermostat as well as the hot air flow..
cyclops is offline   Reply With Quote
Old 15th September 2008, 12:40   #40
BHPian
 
Path_Finder's Avatar
 
Join Date: Jul 2008
Location: Bangalore
Posts: 623
Thanked: 5 Times
Default

Quote:
Originally Posted by amu1983 View Post
Good to know that there's no such thing as the 2 minute rule! Even I like using the AC button as the Nitro booster, especially when I badly need some power and don't want to strain the engine too much (with the AC and the acceleration). Even I was worried about the health of my compressor, and the ill effects of frequent ON/OFFs. Good to know about the 7 year-WagonR guy.
I think I was the one who mentioned first about this 2 minute rule; that was based on how a typical home a/c is set to operate and its instructions. Good to see the experience shared here on the forum and that lower times do not really affect the performance or durability. It could also because that the modern units are built to last better.

I was observing the automatic cut-off happening on my CEDIA while idling after seeing this thread. Know what? While I was idling with a/c on I was observing that the compressor was getting automatic on & off every 40-45 seconds!! So that blows the myth off the 2 minute rule. So go after the “nitro booster” when you need it most.
Path_Finder is offline   Reply With Quote
Old 17th September 2008, 13:14   #41
BHPian
 
viper_711's Avatar
 
Join Date: Jan 2008
Location: Bangalore
Posts: 346
Thanked: 55 Times
Default

Quote:
Originally Posted by cyclops View Post
but i guess merve's post has made the concept clear for us.
the blue-red knob controls the thermostat as well as the hot air flow..
No dude! read his post carefully - he has said that the thermostat is fixed usually between 2 and 5 degrees and that the knob controls flow of hot coolant / air over the heater coil. You cannot control the temperature setting the way you can in a home window / split unit.
Hope it's clear now. cheers!
viper_711 is offline   Reply With Quote
Old 17th September 2008, 13:33   #42
BHPian
 
cyclops's Avatar
 
Join Date: Mar 2008
Location: Pune
Posts: 297
Thanked: 9 Times
Default

Quote:
Originally Posted by viper_711 View Post
No dude! read his post carefully - he has said that the thermostat is fixed usually between 2 and 5 degrees and that the knob controls flow of hot coolant / air over the heater coil. You cannot control the temperature setting the way you can in a home window / split unit.
Hope it's clear now. cheers!
yes man, as per him as well the thermostat is not controlled by the knob.

but i can definitely experience the frequent cut-off of the AC with the knob towards red as compared to completely towards blue

umm.. maybe i'm wrong, but I think it must be due to less air is being blown through the cooling coil when the knob is set more towards red.. as the flap will be directing more hot air in the mixture.. what say?
cyclops is offline   Reply With Quote
Old 17th September 2008, 18:14   #43
BHPian
 
viper_711's Avatar
 
Join Date: Jan 2008
Location: Bangalore
Posts: 346
Thanked: 55 Times
Default

Quote:
Originally Posted by cyclops View Post
but i can definitely experience the frequent cut-off of the AC with the knob towards red as compared to completely towards blue

umm.. maybe i'm wrong, but I think it must be due to less air is being blown through the cooling coil when the knob is set more towards red.. as the flap will be directing more hot air in the mixture.. what say?
Now that you're on this side of the fence - try and observe carefully for the next fifteen days - We have a palio sport 1.6 and an Indica TDI in the family. I too will try and observe what you say on both the cars (Hell, at most times in Bangalore weather one needs to tweak the temperature settings of the AC, especially on long commutes) Let's share views after that.
viper_711 is offline   Reply With Quote
Old 9th July 2009, 16:43   #44
Distinguished - BHPian
 
jkdas's Avatar
 
Join Date: Sep 2005
Location: Thiruvananthapu
Posts: 9,661
Thanked: 1,389 Times
Default

How is the condenser and evaporator linked?
jkdas is offline   Reply With Quote
Old 10th July 2009, 12:19   #45
Senior - BHPian
 
mithun's Avatar
 
Join Date: Jan 2006
Location: Cochin
Posts: 1,950
Thanked: 49 Times
Wink

See this pic :

Name:  ac.gif
Views: 377
Size:  16.0 KB

Courtesy : Air Conditioning, Page 1 of 3

Last edited by mithun : 10th July 2009 at 12:20.
mithun is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Innova Purchase Query + Query on Price Increase by Toyota SanMan SUVs, MUVs & 4x4s 7 30th April 2008 13:13
Swift (Running-in) Query abhi1881 Technical Stuff 11 2nd August 2005 09:45
Longest running model names Aditya The International Automotive Scene 16 29th May 2004 04:25
Mercedes India running BioDiesel Tests GTO The Indian Car Scene 1 21st April 2004 23:46


All times are GMT +5.5. The time now is 23:01.

Copyright ©2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks