Will A/C blower speeds affect the Fuel Economy?

arunkumar_rec · 18th December 2007, 08:29

Thanks for all your inputs. I will atleast set the dealer right so that they wont misguide their customers regarding the A/C blower speeds.

Arun

dvswift · 19th December 2007, 07:50

As it was pointed out, Blower is an electrical load which is going to run on the battery.
The moment you are discharging the battery, the Alternator kicks in. The more you are discharging the battery, the longer the Alternator would run and hence lower the FE. Blower Speeds do matter.

saurabh159 · 19th December 2007, 10:40

Hi,
Does the same logic of A/c blower speed applies also in the condition when only heater is on ?
Whats the effect of A/c verses Heater on the FE ?

arunkumar_rec · 19th December 2007, 11:06

I feel using the heater should not affect the FE as the heat is derived from the engine heat which anyway goes as a waste. Please correct me if I am wrong.

ragzv · 19th December 2007, 12:06

Yes the car heater very much uses engine heat (in most cars) , thus when a engine is cold it takes some time for the hot air to come.

Few cars also come with coil based heaters. I remember my cousin who had fitted an after-market coil based heater in his Maruti 800 as in Amritsar the temp reaches 0 degrees or below and by the time the engine heated up they were already frozen.

murugaveln · 19th December 2007, 12:52

The manual also says to set the airflow knob to let outside air flow instead of recycling air when the a/c is on. Does this also have any efffect on the FE?

Thanks.

arunkumar_rec · 19th December 2007, 13:37

Yes. FE will be affected. This has been discussed before. The A/C unit will consume more fuel to cool the hot outside air when the A/C is kep it in fresh air mode. If the A/C is kept in recirculation mode, load on the compressor is less as the inside air is already cool. So better FE.

Maverick1977 · 19th December 2007, 14:07

Quote:

Originally Posted by dvswift

As it was pointed out, Blower is an electrical load which is going to run on the battery.
The moment you are discharging the battery, the Alternator kicks in. The more you are discharging the battery, the longer the Alternator would run and hence lower the FE. Blower Speeds do matter.

DVSWIFT ---> I beg to differ that using just the blower will have an effect on the FE. In such a case the FE will be reduced if you are playing the ICE. Of course it depends on the type of ICE, but a regular HU & 4 speakers would not make such a great impact on the battery consumption.

rider60 · 21st February 2008, 01:32

well there this little OT i think, had to mention this, i one happened to notice during my trip to goa in my sweet beast the same red accent viva crdi, we had a thermocol box with ice in it and lots of redbulls and colas, the ice stayed more solid than becoming water for the whole trip back which we made in 1 day, and the boot too was so cool and chilled that all our luggage was chilled too!

man damn came to me as a surprise, as i never expected this, i guess this the benefit of the car being a hatch back! and never did i even once feel the car lacked the power to pull even with the a/c running in full blast all the time till it fell dark and a little cooler outside!, and let me tell you there were 5 of us and the boot was jam packed too!

the car happened to pleasantly surprise me! kudos to crdi!

oah yes forgot to mention, the FE was 14kmpl with the speeds toughing even 160 and a consistant 100-140 depending on the roads, it was the express highway where i got to floor the beast and even with this kind of load the car pulled effortlessly and that kind of FE man am i happy you ask? i was thrilled to be surprised!
damn should write up my long term report too soon!

dvswift · 26th February 2008, 00:23

Quote:

Originally Posted by rks

I don't think these are classified as rear A.C. vents, because they don't blow air. I am not aware of the situation in other cars in this range. I had always assumed that the recirculating air to the blower suction will be drawn from both the front and back sides of the car in order to have good circulation for all passengers.

There is no duct work in the Santro to provide airflow to the rear. I think they are just superficial arrows shown in the picture. In such cars, the vents above the center console are supposed to provide airflow to the rear seats.

The suction path (when in recirculation), is located below the dash. The backside of the car has only a body relief valve to regulate the positive air pressure inside the cabin w.r.t the atmosphere.

amitpunjani · 26th February 2008, 09:54

i think there is bit of relation between effect on F.E and the blower speed. The compressor is connected to the thermostat of the cooling coil. The cool air passes throught the thermostat and whenever the thermostat reaches at certain temperature it will trigger the compressor to cut off, hence no load on the engine of A/C and more F.E.

If the blower speed is always kept at no 2 position, this will allow efficient cooling of air and hence also of the thermostat which will trigger off the compressor.

Amit

ankan · 25th May 2009, 20:15

Sorry if a similar topic already exists. I searched but could not fine any.

The thing i wanted to know is if any of the gurus here can tell me if keeping the blower speed at 2 will give different fuel consumption figures than keeping
the blower speed at full.

conditions:
1. ac running for same duration.
2. same no of kms driven.

the question suonds stupid but always wanted to know i guess

Note from Team-BHP Support : Thread MERGED. Please use the search feature before creating a new thread on a topic that might already exist. Please continue your discussion in an existing thread. This will keep all the relevant information in one place and make it easier for readers in the future.

drvarunagarwal · 25th May 2009, 22:34

What about cars with automatic climate control? Will higher temp eg 20 give better mileage than 18 degrees?

GTO · 26th May 2009, 11:22

Quote:

Originally Posted by drvarunagarwal

What about cars with automatic climate control? Will higher temp eg 20 give better mileage than 18 degrees?

Logically, I think so as the compressor will work less harder at 20 vis a vis at 18.

gpa · 14th June 2009, 23:41

Quote:

Originally Posted by GTO

Logically, I think so as the compressor will work less harder at 20 vis a vis at 18.

I checked this today in my friend's Swift ZXi which has the climate control system. We sat in the car and revved the engine to 2000 rpm and the cut out was longer (approx 2 mins) when the climate control was set at 21 deg than when it was set at the minimum of 18.5 deg (42 secs).

Bear in mind that this was done at 1.30 pm in the afternoon with an ambient temperature of 28 deg and the car parked under the blazing sun.

18th December 2007, 08:29	#31
arunkumar_rec BHPian Join Date: Aug 2007 Location: Chennai Posts: 106 Thanked: Once	Thanks for all your inputs. I will atleast set the dealer right so that they wont misguide their customers regarding the A/C blower speeds. Arun
	() Thanks

19th December 2007, 07:50	#32
dvswift Newbie Join Date: Jul 2007 Location: Bangalore Posts: 18 Thanked: 0 Times	As it was pointed out, Blower is an electrical load which is going to run on the battery. The moment you are discharging the battery, the Alternator kicks in. The more you are discharging the battery, the longer the Alternator would run and hence lower the FE. Blower Speeds do matter.
	() Thanks

19th December 2007, 10:40	#33
saurabh159 BHPian Join Date: Aug 2007 Location: Mumbai Posts: 94 Thanked: 10 Times	Hi, Does the same logic of A/c blower speed applies also in the condition when only heater is on ? Whats the effect of A/c verses Heater on the FE ?
	() Thanks

19th December 2007, 11:06	#34
arunkumar_rec BHPian Join Date: Aug 2007 Location: Chennai Posts: 106 Thanked: Once	I feel using the heater should not affect the FE as the heat is derived from the engine heat which anyway goes as a waste. Please correct me if I am wrong.
	() Thanks

19th December 2007, 12:06	#35
ragzv BHPian Join Date: Oct 2007 Location: Kolkata Posts: 107 Thanked: 8 Times	Yes the car heater very much uses engine heat (in most cars) , thus when a engine is cold it takes some time for the hot air to come. Few cars also come with coil based heaters. I remember my cousin who had fitted an after-market coil based heater in his Maruti 800 as in Amritsar the temp reaches 0 degrees or below and by the time the engine heated up they were already frozen.
	() Thanks

19th December 2007, 12:52	#36
murugaveln Newbie Join Date: Nov 2007 Location: Coimbatore Posts: 22 Thanked: 5 Times	The manual also says to set the airflow knob to let outside air flow instead of recycling air when the a/c is on. Does this also have any efffect on the FE? Thanks.
	() Thanks

19th December 2007, 13:37	#37
arunkumar_rec BHPian Join Date: Aug 2007 Location: Chennai Posts: 106 Thanked: Once	Yes. FE will be affected. This has been discussed before. The A/C unit will consume more fuel to cool the hot outside air when the A/C is kep it in fresh air mode. If the A/C is kept in recirculation mode, load on the compressor is less as the inside air is already cool. So better FE.
	() Thanks

21st February 2008, 01:32	#39
rider60 Senior - BHPian Join Date: Mar 2007 Location: Bhagyanagaram. (A.K.A. Hyderabad) Posts: 1,620 Thanked: 56 Times View My Garage	well there this little OT i think, had to mention this, i one happened to notice during my trip to goa in my sweet beast the same red accent viva crdi, we had a thermocol box with ice in it and lots of redbulls and colas, the ice stayed more solid than becoming water for the whole trip back which we made in 1 day, and the boot too was so cool and chilled that all our luggage was chilled too! man damn came to me as a surprise, as i never expected this, i guess this the benefit of the car being a hatch back! and never did i even once feel the car lacked the power to pull even with the a/c running in full blast all the time till it fell dark and a little cooler outside!, and let me tell you there were 5 of us and the boot was jam packed too! the car happened to pleasantly surprise me! kudos to crdi! oah yes forgot to mention, the FE was 14kmpl with the speeds toughing even 160 and a consistant 100-140 depending on the roads, it was the express highway where i got to floor the beast and even with this kind of load the car pulled effortlessly and that kind of FE man am i happy you ask? i was thrilled to be surprised! damn should write up my long term report too soon! Last edited by rider60 : 21st February 2008 at 01:35.
	() Thanks

26th February 2008, 09:54	#41
amitpunjani BHPian Join Date: Jul 2007 Location: Delhi Posts: 451 Thanked: 109 Times	i think there is bit of relation between effect on F.E and the blower speed. The compressor is connected to the thermostat of the cooling coil. The cool air passes throught the thermostat and whenever the thermostat reaches at certain temperature it will trigger the compressor to cut off, hence no load on the engine of A/C and more F.E. If the blower speed is always kept at no 2 position, this will allow efficient cooling of air and hence also of the thermostat which will trigger off the compressor. Amit
	() Thanks

25th May 2009, 20:15	#42
ankan BHPian Join Date: Feb 2009 Location: guwahati Posts: 38 Thanked: 13 Times	Effect of AC blower speed on fuel consumption. Sorry if a similar topic already exists. I searched but could not fine any. The thing i wanted to know is if any of the gurus here can tell me if keeping the blower speed at 2 will give different fuel consumption figures than keeping the blower speed at full. conditions: 1. ac running for same duration. 2. same no of kms driven. the question suonds stupid but always wanted to know i guess Note from Team-BHP Support : Thread MERGED. Please use the search feature before creating a new thread on a topic that might already exist. Please continue your discussion in an existing thread. This will keep all the relevant information in one place and make it easier for readers in the future. Last edited by Jaggu : 25th May 2009 at 20:49. Reason: Use search please
	() Thanks

25th May 2009, 22:34	#43
drvarunagarwal BHPian Join Date: Apr 2009 Location: Bareilly Posts: 40 Thanked: 4 Times	What about cars with automatic climate control? Will higher temp eg 20 give better mileage than 18 degrees?
	() Thanks