Rosewill RX-358 ext. hardrive. Safe to operate with fan off?

Newegg.com - Rosewill RX-358 V2 SLV (Silver) 3.5" SATA to USB & eSATA External Enclosure w/Int.80mm Fan

Here's a link to my product. I've got a 2 TB WD green drive in it. I'm wondering if I can turn the fan switch off on this when this is hooked up to my popbox media player which reads my 1080p mkv movies from the hardrive. I notice the green drive spins down on it's own when I turn off my popbox which is important but the fan doesn't turn itself off any I don't want to leave it on all the time nor do I want to have to be manually turning it off and on all the time. With the fan turned off can anyone tell me what's the coolest orientation for enclosure to be in? Vertical, horizontal, upside down? When the fan grille is facing up the hard drive is inverted. I know hard drives work fine vertically but I wasn't sure about inverted. Ofcoarse I'll turn the fan on when I hook hardrive up to PC for mass file transfers.

Personally I would suggest not too....because heat is the number one factor in HDD failures. Having a look at the link you provided and reading through some of the feedback posts, over all the unit has a good rating. There are a few that mention leaving the fan on when unit is plugged in due to the overheating issue.

A simple way to resolve the problem would be to add a temperature switch to the case that would turn the fan on and off at the desired temp range with such an item as this: 12V Digital Temperature Control 0

I have that same enclosure and thought the fan didn't work. I ran it for 8 months before I was changing drives and noticed a wire disconnected. It never overheated on me, but I agree with the above comments. If you have a fan, it is much safer to use it.

Is there a built in sensor in hardrive and software for my PC so that If I plug my external hardrive into my usb of my laptop the PC will tell me how hot external hardrive is?

Not that I am aware of, but Crystal Disk Info will.

That is free software that will be able to read my external hardrive temps? The hardrive already has an external sensore then? Thanks!I'm thinking about playing a movie from my popbox for a while hooked up to hardrive with fan off and then quickly attach it to PC and do this to measure temp.