Technical Rad fan on when using AC

[BarrySpiers]

Hi all,
I recently had my AC condenser radiator changed due to it having a hole in it, the system was regassed and the AC is working great. However, I’ve noticed the Rad Fan seems to be on all the time when using the AC and stays on for a short while after the ignition is turned off, if I run the car without AC this does not happen. Is this normal or should I take the car back to the garage? I should also say that I’m in Spain and it’s very warm!
Any help or advice would be welcomed…….

 

[Pugglt Auld Jock]

Hi all,
I recently had my AC condenser radiator changed due to it having a hole in it, the system was regassed and the AC is working great. However, I’ve noticed the Rad Fan seems to be on all the time when using the AC and stays on for a short while after the ignition is turned off, if I run the car without AC this does not happen. Is this normal or should I take the car back to the garage? I should also say that I’m in Spain and it’s very warm!
Any help or advice would be welcomed…….

Not unusual for the radiator fan to run when air con is working as it draws air through the condensor (looks like a second radiator, usually in front of the main cooling system radiator.) With the aircon off the fan is controlled by the temperature of the coolant and will only come on when the coolant gets hot enough so you can expect to hear it cutting in and out. Both my Skoda and SEAT were like this. Probably nothing to worry about, but check the coolant level in the radiator as it might be staying on because the coolant is low and not cooling the engine properly. (remember not to take the cap off the coolant tank when the engine is hot unless you want a scalding!)

 

[PuntoHowTo]

very normal

as jock said. The fan is to cool the aircon condenser.

the basics of air conditioning is that a compressor, squeezes' the gas to a high pressure and in doing so the gas gets hot. then the gas is released through a valve allowing it to expand rapidly and in doing so it cools down rapidly like when you use an aerosol can for a long time the can will get cold.

But the fan or the movement of the car will keep air flowing through a radiator to cool the gas when it has just been squeezed to take some of the heat out of it. This makes it much more efficient when the gas is released and expands inside components inside the cabin cooling down the inside of the cabin. Basically think of it as a heat pump, it takes heat out of the air inside the cabin, that heat is transferred to the gas which then gets expelled via a radiator under the bonnet. If the car is not moving then the fan comes on to cool the gas.

I've probably over explained it, but yeah its perfectly normal.

 

[BarrySpiers]

Not unusual for the radiator fan to run when air con is working as it draws air through the condensor (looks like a second radiator, usually in front of the main cooling system radiator.) With the aircon off the fan is controlled by the temperature of the coolant and will only come on when the coolant gets hot enough so you can expect to hear it cutting in and out. Both my Skoda and SEAT were like this. Probably nothing to worry about, but check the coolant level in the radiator as it might be staying on because the coolant is low and not cooling the engine properly. (remember not to take the cap off the coolant tank when the engine is hot unless you want a scalding!)

Thank you, that makes perfect sense, cheers buddy.

 

[BarrySpiers]

very normal

as jock said. The fan is to cool the aircon condenser.

the basics of air conditioning is that a compressor, squeezes' the gas to a high pressure and in doing so the gas gets hot. then the gas is released through a valve allowing it to expand rapidly and in doing so it cools down rapidly like when you use an aerosol can for a long time the can will get cold.

But the fan or the movement of the car will keep air flowing through a radiator to cool the gas when it has just been squeezed to take some of the heat out of it. This makes it much more efficient when the gas is released and expands inside components inside the cabin cooling down the inside of the cabin. Basically think of it as a heat pump, it takes heat out of the air inside the cabin, that heat is transferred to the gas which then gets expelled via a radiator under the bonnet. If the car is not moving then the fan comes on to cool the gas.

I've probably over explained it, but yeah its perfectly normal.

Many thanks, that’s put my mind at rest