Do you only use your car's air conditioning in the summer? Many drivers think that they will prolong its life if they don't use it that often. However, the opposite may be true.
One of the purposes of air conditioning is to provide dry air. Fog happens when water condenses on the window. In the winter, keep your car's temperature setting to hot and turn on the air conditioning. You'll see that defrosting your front windshield is that much faster. The reason is because the air coming out of the vents is dry, so the A/C system is like a dehumidifier.
Another thing to consider is this: your car's air conditioning system is filled with parts that were meant to move. With our bodies, if we stop moving for a while muscles start aching, we lose circulation, etc. It's not healthy. The same is true for your car. If you don't use your air conditioner for a few months, some components (such as the A/C compressor clutch) may become seized.
Your car's air conditioning system is filled with refrigerant and a small amount of oil. It's a good idea to get that liquid flowing every now and again, rather than having it sit for long periods as the oil helps keep important air conditioning components lubricated.
Lastly, bacteria and mould tend to build up in a system that is not regularly used. Ever turn on your A/C after not using it for a while and notice a bad odour? Ya, you can guess what you're smelling. There are in-car air quality services that your repair shop can do to address the smell, but why not just run your A/C every now and again?
This winter, as part of maintenance, use your car's air conditioning regularly (keep the temperature setting to hot). If not, you may end up with higher repair costs for your air conditioning system.