What is the ideal temperature setting for a car A/C and how to set the A/C temperature for an increased cabin comfort.

COPYRIGHT WARNING:
All pictures and texts in this web page are the property of nomaallim.com. Any use of any part of those contents without the written consent of nomaallim.com shall be subject to legal procedures as per international and local laws in the concerned country. Using the name "nomaallim" or "nomaallim com" or "nomaallim.com" in the text describing the unauthorized copied content shall not constitute an exception and shall be sanctioned in accordance to the effective laws and proceedings.

Main causes of car A/C discomfort

Cars having no climate control system can still provide a comfortable A/C the blown air temperature is regulated as explained in this tutorial.

Cars equipped with an automatic or semi-automatic air conditioner, must be set to the right temperature.

Most drivers would simply turn the A/C on without any temperature setting or simply set it to "LOW" or "MAX" which could lead to discomfort in the vehicle especially at night in the absence of the heat of the sun.

A/C discomfort in cars is in general due to any of the below factors or to a combination of these:

Absence of pollen or cabin filter
No timely replacement of the A/C filter when fitted
No temperature regulation on manual air conditioners (see below how to regulate it)
No proper temperature setting on automatic air conditioners
Loss of efficiency due to refrigerant leaks
A/C grilles pointing directly to chest or head
A/C recirculation mode kept on for too long
A/C recirculation mode kept off in traffic jams

DISCLAIMER:
Our pictorials are of informative nature and do illustrate works carried out by ourselves at our own premises for our own use and satisfaction.
Readers who envisage to carry out similar works inspired by the below method shall do this at their own risks and liability.

Setting the car A/C temperature on manual air conditioning controls

Never turn on the A/C without setting the pulsed air temperature by rotating the heater knob towards the red zone.

Always use the car heater to regulate the A/C temperature to make it comfortable.

You can add as much heat as needed, there is no conflict between the car A/C system which is based on a compressor and refrigerant and the car heater which is fed from the engine coolant circuit

Setting the car A/C temperature on Automatic air conditioners

Set you A/C temperature to 21 degrees celsius (70 degrees Fahrenheit). In case of discomfort, increase or decrease this setting by 0.5 degree only, there's no need for more.
If your car had been parked for a long time in the sun, you may use the "A/C MAX" button for 5 minutes with the windows open, then put it back in Auto mode with the temperature set to 21C/70F.

Setting the car A/C temperature by increments of 0.5 degrees Celsius (1 degree Fahrenheit) is the right way to increase or decrease the A/C temperature setting.

Proper use of the recirculation mode in car air conditioners

The A/C recirculation mode in vehicles is wrongly used most of the time if not all the time by most drivers.

Use the car A/C recirculation mode when:

it's too hot outside to increase the A/C efficiency
you're driving in a traffic jam to avoid the bad smells and toxic gases from the vehicle in front of you

Open your car and let fresh air come in when:

highway driving (see below)
defogging your windshield

IMPORTANT NOTE: never keep the car A/C recirculation mode on for more than an hour without ventilating the vehicle by either opening the windows for a minute or removing the recirculation mode for a few minutes.
It is not a good idea to use the recirculation mode during highway driving as this could lead to excess CO2 in the cabin and consequent increased risks of drowsiness.