Efficient use of A/C

[Genie47]

OK with fuel prices at an all time high, efficient use of the A/C is important.

 

Unless you go all out not using the A/C to conserve fuel, this is not important to you. However, living here in the tropics, the A/C is a godsend.

 

How to use it efficiently?

 

Firstly know this:

 

1. The fan actually draws very little power from the engine for A/C use.

2. The compressor draws the most power.

3. The compressor cycles in a certain frequency to keep the evaporator core at the desired temperature.

4. Higher fan speed will make the evaporator absorb more heat causing the compressor to cycle faster AKA run more.

 

OK from all these here is my strategy on how I achieved very good FC even with the A/C.

 

1. Start engine.

2. Turn off recirculation. Yes turn it off. Open all windows if it is really very hot.

3. Turn to max cooling (temperature control knob).

4. Turn to max fan (fan speed control).

 

Now drive off.

 

Once the temperatures are comfortable:

 

1. Turn on recirculation.

2. Reduce cooling to the last blue bar before they start mixing with the red bar.

3. Reduce fan to minimum required.

 

Now the reason is this. When starting off, turning off recirculation will bring in cooler air into the cabin. Even when a car is parked in a sheltered place, the interior is still warmer than the external air. This is always the case. In open spaces and under the sun, opening the windows will alow more air to come in. Driving actually allows cooler air to enter the cabin.

 

Once the temperature drops. Reducing everything actually just removes moisture out of the car which maintains its cool temperature rather than outright refrigeration of your cabin. You save energy in the end.

 

An internal thermometer helps to gauge the temperature in your car to do this.

[Kwongwing]

Thanks for the advice

My thermometer usually shows the temp near 40 deg. c when I 1st get into the car - like hell.

[Serag15]

any reflections on the fc

[Genie47]

Coupled with my driving style for my car, I achieve. 13-14km/L.

 

I forgot to mention this. When the air outside is humid, the windows will fog. When this happens your A/C is too cold. Lower the temperature more and even into the red zone. at the correct temperature much can be saved if you just remove the moisture inside. This usually happens at night and mostly in traffic jams.

Edited September 7, 2005 by Genie47

[Titanium]

  Quote

OK from all these here is my strategy on how I achieved very good FC even with the A/C.

 

1. Start engine.

2. Turn off recirculation. Yes turn it off. Open all windows if it is really very hot.

3. Turn to max cooling (temperature control knob).

4. Turn to max fan (fan speed control).

 

AC on or off?

[Genie47]

My A/C always on. I want to load the car as much as possible to warm up the engine.

[Kanr]

Just hv to pay only,bro!!!!

[Ahliew]

does turning off recirculation = you get fumes from the roads?

[Genie47]

Who ask you drive behind lorry. Small price to pay. You cool down faster with this method.

[Cor66]

Tried that last time on my previous car... one time, my thermostat burnt... the tech told me i adjust the temp knobs too often... not sure if its true

[Genie47]

What the tech told you is a load of bovine feces.

[Bommii]

  Quote

My A/C always on. I want to load the car as much as possible to warm up the engine.

I think you should not load the engine to warm up. I feel warm up should be smooth.

Once a mechanic adviced me not to switch on a/c for the first km or so when you take out the car for the first time in the morning. Its better to switch on the aircon after ur engine its warmed up. This is not for better FC but for better maintenance of ur engine.

[Genie47]

My oil is thinner than what most people will put in their engine. It will take higher load but generates little heat from shearing as compared to those using a 40 or 50wt oil.

[Gadgeter]

Noted.. will try,.

[Mubarakrashid]

logical and practical thinking ...will give it a try...but downturn is that i will have to vacuum my interior more often than...

[Cheeze]

How about turning off compressor whenever accelerating or moving off? Does it help reduce FC? I do that most of the time.

[Beanoyip]

Wah then how many times you have to off/on your a/c during a journey?

[DarkLord]

Weird lehz... How come I am feeling that the 5W-30 I am using is creating more heat? My engine bay temp has gone up so did my radiator temp lehz..