philh wrote:
ajriding wrote:
Im not disagreeing, I just saying more airflow will cool the fins faster…
What can happen with wrong fan placement is that the air gets turbulent and does not do a good job flowing through the fins.
Flow too fast, there's not enough time for heat transfer. HOWEVER, in our fridges, they depend entirely on convection for heat transfer. A fan can help increase the flow.
another guy: the cold output temp on Lo fan then med fan then hi fan. You will notice on LO fan, the output is COLDER. Because,
You guys are so out there….
This is not a car AC but similar principals apply. You observation is correct, however your conclusion is wrong. The reason the temp is cooler on low than high is that you are removing a fixed amount of heat (cold) from the evaporator in your dash. The amount of cold coming out, no matter the speed, is actually the same, but by speeding up the air you get more warm air mixed in with the cold.
Actually the higher speed air will put more cold into the car than the slow, even though the slow measures a lower temp. If you put one gallon of 40 degree air into a 80 deg car that wont do much, even though it is cold, but put 10 gallons of 45 degree air in and you will see a difference in car temp. The gallons represent speed. one gallon is slow, 10 is fast.
The faster the air flows the more cool the car becomes. You can raise the speed and this stays true up to the point that the air movement is making too much heat from friction and overtakes the amount the AC compressor can cool. At very high air speeds the fins might feel the same temp as the incoming air.
In your fridge the hotter the fins feel then the less the air is pulling heat from them. Faster airflow will pull more heat. Air molecules do not need "time" to pull heat.
Inside the AC system the airflow is heating up the coolant (134r or freon), and the faster (more) air that contacts the fins the more heat is transferred (up to the point ,at sonic, speeds the air will create heat friction).
This also works up front at the grill where the condenser is, it sits in front of the motor radiator, and both need airflow to work, this is why there is a fan there. The faster the air flows, the more cooling the radiator and condenser will cool the contained liquid and gases.
Higher airflow will cool the refrig fins better, but in reality only a little airflow is needed for the fridge to function, this is why so many people use the tiny computer fans.
