Air Conditioning – Not Just for the Summer


Air conditioning is a feature frequently underused by drivers. As well as providing cool air on hot summer days, air con can help keep your car mist-free when the winter chill sets in. Unfortunately, it does increase fuel consumption at low speeds, so try to use it sparingly if it isn’t needed.

So you can keep your car temperature and air flow at the optimum level, we’ve compiled a quick guide to car air con.

How does car air con work?

The main function of air conditioning is to transfer heat from within the car to the outside. To do this, it uses a refrigerant, R134a, which is pressurised into a condenser. The physics principles that are at work when running air con include compression, expansion, evaporation and condensation. As the refrigerant gas is turned into a liquid and back into a gas, it absorbs heat. The refrigerant essentially chills the indoor air, and the gas is then compressed. It is then cooled back into liquid to repeat, while your fans vent out the cool air.

Winter use

It is less common to use air conditioning in the winter. The system forces water out of the air. Cold air doesn’t hold the humidity that warm air does, so air that comes from the evaporator in your A/C system is cold and dry. It then passes through the heater core, making it perfect for demisting your windshield.

Don’t wipe your glass down with your hand or a towel as it can leave dirty stains. Instead, sit back and let the air con do its job.

Summer use

During summer, the A/C system extracts heat from your car and brings in cool air. To give it the best chance to do so, follow these tips:

  • Use your air con regularly, as systems are most effective under frequent use.
  • If possible, leave the windows of your car open slightly to reduce heat build-up before you drive.
  • When you get in the car, open all the windows completely to help the system.
  • Once you start driving, close the windows to remain fuel efficient. Having your windows down can affect the car’s aerodynamics.
  • Ensure you get the system serviced to avoid any odours or bacteria building up.


Most common air conditioning problems are easy to diagnose but can be tough to fix. Here are the two most common issues:

Cool air but not cold: this can be an issue with the cooling fans on the condenser or radiator. It can also be caused by leaves or dirt blocking the air from passing over your condenser.

Leaks: When pressure is low, there’s often a leak. They can be tough to fix, but often the best way to find one is to use a UV A/C detection kit.