Can a power supply be left outside the case?

[UrAvgGamer]

So, I currently have an Acer XC-605.
Specs: i3-4160
GT-705
1TB HDD
Haswell H81 MOBO (Mini-ITX)
Under 300w PSU (I think it's only 220w)
And a SFF case
here it is - http://complink.com.ph/v2/index.php?route=product/product&product_id=775

I'm looking to upgrade my video card but my psu is not that great.
I think i'll go with a Zotac GTX 750ti. - http://www.lazada.com.ph/zotac-zt-70605-10m-gtx750-ti-2gb-ddr5-128bit-graphics-card-913597.html

I do not want to move every component to another case since i've never built a computer before.
So, incase I do buy a more powerful psu, can i just place it outside the case?
What are the risks of doing this? And how powerful should the psu be to make this work?

 

[N3rdR4ge]

Won't be a problem as long as you don't block any fans or vents wherever you place the psu. 400w will be fine. I'm curious, why not just remove the original psu and install a new one?

 

[UrAvgGamer]

Won't be a problem as long as you don't block any fans or vents wherever you place the psu. 400w will be fine. I'm curious, why not just remove the original psu and install a new one?

Since my case is a small form factor case, I'm guessing that a more powerful psu would be bigger than what I have now.
So, unless I find a 400w that's the has the same dimensions, I will have to keep it outside.

 

[ShadyHamster]

Sliverstone make SFX (small form factor) PSU's, have a look at them and see if the dimensions match up.
Seasonic make some non standard form factor PSU's too, if it's a weird oem PSU you are trying to replace.

 

[UrAvgGamer]

Sliverstone make SFX (small form factor) PSU's, have a look at them and see if the dimensions match up.
Seasonic make some non standard form factor PSU's too, if it's a weird oem PSU you are trying to replace.

What's a "weird OEM PSU"?

 

[ShadyHamster]

Some Dell and HP PC's have used non standard PSU's in the past.
https://www.umart.com.au/umart1/pro/Products-details.phtml?id=10&id2=140&bid=6&sid=71088
Or something like this:
http://www.grrpicturehosting.co.uk/SixBit_2/August/149896-01.jpg

I've also seen PSU's with pieces cut out of the shell or extra bits added to fit around other hardware.

 

[UrAvgGamer]

I don't think those will fit my box... Not sure though... I'm in the Philippines by the way, so I am kinda limited to what I can buy. I am sure that PSUs that are like those are rare in my area so I think that I have a rectangular PSU. No need for those weird ones... hehe

 

[ShadyHamster]

I was just giving examples of odd shaped PSU's, if yours is still rectangular but smaller then a standard ATX PSU then i'd say it would be more like Silverstones SFX PSU's, but take some measurements and compare with other PSU's.

 

[UrAvgGamer]

Will try.... Thanks for everyone's response... Sure do appreciate it....