Lower temp or increase fan speed - which consume more FC?

[Kklee]

For some car i can hear thE compressor turned on sometimes n off again etc, when standing outside the car.

But some car totally no such sound? Why ah

 

Fixed displacement compressor - turn on and off

Variable displacement compressor - always on

 

I recall these days should be all variable displacement already.

[GravityBlue]

Fixed displacement compressor - turn on and off

Variable displacement compressor - always on

 

I recall these days should be all variable displacement already.

1) for aircon system using fixed displacement compressor , best to set at min fan speed

2) no difference for variable compressor since its always running

[Kklee]

2) no difference for variable compressor since its always running

 

Provided it comes with climate control. 

[DACH]

If I am driving alone, usually I will set the about 23 degrees and the lowest fan speed with most of the air vents blowing at me.

 

Sufficient for me to cool down. 

[Aventa]

I usually set the temperature at 23 - 25 degrees at the lowest fan settings.

 

Heard somewhere that opening all the windows creates a drag on the car (aerodynamic issues) and thus higher FC.

[Wildfaye29]

Guys can wear lesser. However woman cannot dun wear bra

 

why woman cannot don't wear bra?

 

can wear clothes but go without bra, no?

[Watwheels]

Huh? Just ask yourself when does the aircon compressor is working under the most load? Usually during startup it will work the hardest. When the compressor is working its hardest that's when it will burn the most fuel. Once reach the temperature you had set it will kick in and out to maintain that temperature. It's best to keep your car parked in a cool environment. The aircon compressor will work less and hence consume less fuel.

 

Aircon works with the feedback sensor and the ambient (outside temperature) sensor to determine how much work to do to keep the car interior cool. All you have to do is touch the "Auto" button and let it do its work. What era liao? Still fiddle with the temperature knob and fan speed knob? Are you serious?

Edited February 19, 2018 by Watwheels

[Kopites]

Nowadays, more & more women wear tank top to run.

 

No different from wear bra.

Those not tank top lah. They call it sport bra. Inside got a small padding. My wife got quite a few.

[Mkl22]

I usually set the temperature at 23 - 25 degrees at the lowest fan settings.

 

Heard somewhere that opening all the windows creates a drag on the car (aerodynamic issues) and thus higher FC.

Proven that the Aircon compressor drinks more fuel than aero drag.

[Watwheels]

My gosh...

 

If you are talking aircon systems of the past whereby there's no feedback sensors to tell the aircon system when to work hard or work less the compressor will just work hard all the way regardless of what you do. On a cold day it will just run so cold it will fog up all your windows no matter how hard you try to demist the windows.

 

Now modern aircon systems are equipped with more sensors to feedback to the unit on what's the cabin temperature and ambient temperature so that the aircon compressor knows when to work hard or work less. In a way it helps with the fuel economy.

[Rustyz]

Can't remember the TV programme name but they compared A/C with open window.

Which had higher f/c.

 

Open window had higher f/c iirc.

 

If i rmb correctly is for speed below 70km/h

 

as the window as cause drag and resistance to motion

[Victor68]

interesting, so far i need not set anything lower than 23C. for me, i always direct the vent to blow upward never mid or leg.

 

reason is simple. hot air rises and cold air sinks.why cool your leg? vent out the air before you drive off instead of trying to cool down the heat gain.

[GravityBlue]

Provided it comes with climate control. 

Still no difference technically.

With variable compressor , it is always running , operations goes on , except output capacity varies according to operating gas pressures.

Whether climate control (digital) or manual control (analog) , your set desired temperature is achieved thru mixing of hot air from radiator coolant (aka heater coil). Doesn't mean that when u set to 23 deg , the comp will run lesser/slower.

How to identify fix / variable comp ?

If u can feels engine rpm changes when comp cuts in/out , its a fixed compressor.

If don't feel any changes/vibration thru out , its a variable compressor.

[Hamburger]

driving on the road and thinking what temp for the air con is the last thing in my mind.

 

Just blast it!

[Mkl22]

wah lao eh.. think until so hard to save $$ for petrol. Don;t drive la. take Bus or MRT... aircon no extra charge.

[Kia7200]

For residential ac. Fan motor consume very little electric, it's the temp diff that cause the compressor to run harder thus higher power consumption.

 

My guess is temp will save more fc

[Cheesey74]

Seriously such thoughts nvr cross my mind at all...

Lower aircon temp to save fuel...geez!

[Kklee]

Still no difference technically.

With variable compressor , it is always running , operations goes on , except output capacity varies according to operating gas pressures.

Whether climate control (digital) or manual control (analog) , your set desired temperature is achieved thru mixing of hot air from radiator coolant (aka heater coil). Doesn't mean that when u set to 23 deg , the comp will run lesser/slower.

How to identify fix / variable comp ?

If u can feels engine rpm changes when comp cuts in/out , its a fixed compressor.

If don't feel any changes/vibration thru out , its a variable compressor.

 

How does the variable displacement compressor knows how much to vary with manual control ?