How can you determine if the internal fan is on or off? I haven't found any indicators that show that but I'm interested in knowing about it.The fan is actually blowing air into the internal fan intake, meaning its working with the internal fan and not against it. I've found that if I put the SP3 Duct 2.0 on the internal fan never even turns on. The internal fan is brushless ball bearing so it spinning while off will not harm it.
Thanks for the question and interest.