Naked Science Forum

Non Life Sciences => Technology => Topic started by: InCharacter on 22/11/2008 18:15:36

Title: Do magnets on the door affect the function of the fridge?
Post by: InCharacter on 22/11/2008 18:15:36: JBlaughmaster@aol.com asked the Naked Scientists:

Dear Chris and the NTS,

Hello, I was wondering what sort of electrical levels of electricity the average family refrigerator has, due to the many magnets that often cling to them; and if this at some small level works against the machine's effort to cool the interior.

Cheers!
James of Chicago

What do you think?
Title: Do magnets on the door affect the function of the fridge?
Post by: lyner on 23/11/2008 16:03:05: I can't think of any possible effect, except for increasing the weight of the door and making it sag on its hinges - spoiling the door deal.
Title: Do magnets on the door affect the function of the fridge?
Post by: techmind on 24/11/2008 00:06:30: Quote from: InCharacter on 22/11/2008 18:15:36
Hello, I was wondering ... ... due to the many magnets that often cling to them; and if this at some small level works against the machine's effort to cool the interior.

If you had a seriously big magnet (probably a few kg weight at least) on/under the floor very near the motor, then you might possibly magnetically saturate part of the motor which would decrease its efficiency and effectiveness and cause it to get hot...
...but your ordinary little fridge magnets aren't going to make any difference at all.
Title: Do magnets on the door affect the function of the fridge?
Post by: RD on 24/11/2008 00:26:05: Quote from: techmind on 24/11/2008 00:06:30
If you had a seriously big magnet (probably a few kg weight at least) on/under the floor very near the motor, then you might possibly magnetically saturate part of the motor which would decrease its efficiency and effectiveness and cause it to get hot...

Adding magnets can increase the efficiency of an electric motor ...

http://www.metacafe.com/watch/665396/how_increase_speed_of_electric_motor/

(it depends on the orientation of the magnets)
Title: Do magnets on the door affect the function of the fridge?
Post by: lyner on 24/11/2008 09:53:20: fridge motors are induction motors. Extra magnets can't do much more than saturate the iron and increase losses.