Corsair TX 850 mounted upside down?

I was thinking about mounting my psu upside down so it will draw air from inside the case instead of the outside. My "perhaps flawed" thought process is that it would help exhaust air from inside the case. I can't think of any physical reasons it wouldn't work but I have been wrong before.

That's how they all used to be mounted, it could be said that using air from inside the case is right side up, really. The fresh air for the PSU bit is fairly new.
That PSU has a temperature controlled fan so it won't be doing a whole lot of exhausting, but it'll do some.
There certainly isn't any reason not to do it.

Thanks!