Did you know? When defrost mode is selected, your air conditioning compressor is actively operating.
On cold mornings it is essential to operate your vehicle´s heater system in the defrost mode to clear the windows inside and out. In defrost mode the heating system should rapidly clear your windows for safe driving. If your vehicle has air conditioning it is important to know that when the defrost mode is selected the air conditioning compressor is engaged.
There are two reasons for running the air conditioning compressor in defrost mode. The primary reason for running incoming defroster air through the air conditioning system is the fact that it dries the moisture from the air and allows the windows to be cleared in a fraction of the time it takes a non air conditioned vehicle which must wait for the engine to warm first. The second reason is that running the air conditioning system allows the compressor and A/C components to lubricate throughout the year. This way the A/C system is ready in hot or cold weather with a minimum of corrosion-related breakdowns.
The main point of this article is to make you aware that if you have a vehicle with air conditioning you should only run it in the defrost mode when it is needed. If you are able to run your heating controls in the economy or normal heating mode and keep the windows clear, do so. This will save wear and tear on your vehicle´s A/C system and could potentially save you a lot of money in fuel cost by not running the horsepower-robbing A/C compressor.