OK folks, with the summer heat arriving, it’s time to discuss air conditioning. There is a major misconception I’d like to clear up.
Let’s review how air conditioning works. Basically, an air conditioner is a heat pump.
Using a few important thermodynamic principles, air conditioners are machines that move heat from one area to another. Typically, they move the heat from inside to outside.
The part of the air conditioner that gets cold in this process is know as the evaporator coil. Warm air from inside blows over the evaporator coil. The heat goes in and gets pumped outside and the cold air returns inside.
Fairly straightforward, no? Air conditioners really only work at one speed. When they are on, the pump heat out. When they are off, they don’t do anything.
Here’s where people get into trouble.
Modern electronics in thermostats and car air conditioners now allow people to dial in the temperature they want. The air conditioner (or heater) is turned on or off to adjust for the desired temperature.
It seems people think that if they turn the knob way down that the air conditioner will work much better. Typically, you see people turning the thermostat as low as it will go to get it cold. This does nothing to help the cooling.
Turn the dial or knob to the temperature you want and leave it alone.
There are a few cases where there you can have variable air speeds blowing over the evaporator coils. This is what ‘Max AC’ is if you see it in your car. Maximum airflow.
Guess what, your thermostat understands if it has variable airflow and uses it when it makes best sense. Believe it or not, the people that design air conditioners know more about how to make air conditioners work than you do.
So, please people, don’t turn that dial down to sixty degrees unless you work in a meat locker.
I disagree. My thermostat really only has 3 settings (the way I use it at least): Super hot, Off, Super cold. It’s a way of showing off. Think of it like revving your engine at a stop light: it’s dumb, pointless, but if your engine is louder than the car’s next to you, you win. Similarly, if someone comes over and your home is at 68 degrees, they think “wow, you have a great air conditioner!” You win. It’s a guy thing.
Well, since you seem to have some knowledge in this area: What does that little button with the circular arrow inside the vehicle do? Circulating air?
My guess:
When the button is pushed is pulls air from the outside of the car. When it isn’t pushed it recirculates the air inside the car. Or vice versa. One way gets fresh air from outside the other reciruculates that fart again and again and again. 😉
You and your fancy airconditioning unit make me sick. Let me tell you this, shoving 12 ice cubes in my underwear cools me twice as fast as 6 ice cubes.
I heard this same lecture from Dave Lansdown about ten years ago.
There is nothing new under the sun.
My wife knows all this, but it still makes her feel better to turn it down. It’s all psycho-logical.
My experience has been that the amount of hot or cold air that blows through the vents depends on the temperature difference between the outside and the temperature to which the thermostat is set. Given that on a hot day with full sun a car heats very rapidly, I find the car cools down fastest when the thermostat is set at the lowest setting, which it never reaches because the sun is heating the car almost as fast, and if it’s really hot faster, than the air conditioner can cool it. The best I can hope for sometimes is the cold breeze.