[Elecraft] Quiet fans for K3

[drewko]

What are the current options for quiet fans for the K3? My original fans 
are pretty quiet but at this time of the year when the windows are 
closed and the ambient noise level is nil, the fan noise really starts 
to bug me. It's the very slight rattle they make when they start winding 
up.. (In the din of summertime, can't hear myself think, let alone fan 
noise.)

Sources? Prices?

Are the newer Elecraft fans quiet? My PA is only a couple of years old 
so the fans are pretty recent model.

73,
Drew
AF2Z