Fitting new PSU

  • Thread starter Thread starter RB
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R

RB

Stupid question I'm sure but...

Have just bought a Nexus 3500 PSU. See http://www.nexustek.nl/nx3500.htm.

Can this be installed either way up, i.e. with the single big fan on top
or at the bottom? And if so which way is preferable? With the label the
right way up the fan would be at the top but the switch and socket is the
other way up and I thought having the fan at the bottom would stop the unit
filling with dust. Your advice appreciated.
 
RB said:
Stupid question I'm sure but...

Have just bought a Nexus 3500 PSU. See http://www.nexustek.nl/nx3500.htm.

Can this be installed either way up, i.e. with the single big fan on top
or at the bottom? And if so which way is preferable? With the label the
right way up the fan would be at the top but the switch and socket is the
other way up and I thought having the fan at the bottom would stop the unit
filling with dust. Your advice appreciated.
Click to expand...
 
RB said:
Stupid question I'm sure but...

Have just bought a Nexus 3500 PSU. See http://www.nexustek.nl/nx3500.htm.

Can this be installed either way up, i.e. with the single big fan on top
or at the bottom? And if so which way is preferable? With the label the
right way up the fan would be at the top but the switch and socket is the
other way up and I thought having the fan at the bottom would stop the unit
filling with dust. Your advice appreciated.
Click to expand...

To get the most heat extracted you'd want the fan drawing air from the top,
but most cases rarely have enough room above the PSU to do this effectively.
Having it at the bottom will pull the air from one of the warmest areas
though - around the CPU.

Most PSU's will only install in one direction because of the screw layout in
the rear.
 
To get the most heat extracted you'd want the fan drawing air from the top,
Click to expand...

There would be almost no difference in temperature (say 0.001 C :o) )
between the top of the PSU and the bottom of the PSU. So I think thats
a bit redundant.
but most cases rarely have enough room above the PSU to do this effectively.
Having it at the bottom will pull the air from one of the warmest areas
though - around the CPU.
Click to expand...
Absolutely, the best place. Gets the heat, from the CPU, out of the PC
as quickly as possible.
Most PSU's will only install in one direction because of the screw layout in
the rear.
Click to expand...
yep.
 
Noozer said:
Most PSU's will only install in one direction because of the screw layout in
the rear.
Click to expand...

Aw, that makes it easier, screw layout is for fan at the bottom. Have turned
the label up the other way. :)

Cheers.
 
There would be almost no difference in temperature (say 0.001 C :o) )
between the top of the PSU and the bottom of the PSU. So I think thats
a bit redundant.
Click to expand...

It would be hotter if fan were drawing air from the top, significantly
hotter. Keeping temp low depends on removal of heat, in most direct
manner possible. By having fan on bottom the heat from CPU can't mix with
other air on it's way to the top of the case. By having fan on bottom
less preheated air is recirculated though the heatsink. By having fan on
bottom the motherboard circuitry is better cooled. There is only one
possible benefit to a fan on the top side, marginally better cooling of a
component in an upper 5 .25" bay, but that's far outweighted by benefit of
fan on the bottom.
 
RB said:
top,

There would be almost no difference in temperature (say 0.001 C :o) )
between the top of the PSU and the bottom of the PSU. So I think thats
a bit redundant.
Click to expand...
Absolutely, the best place. Gets the heat, from the CPU, out of the PC
as quickly as possible.
Click to expand...

Better yet... Specifically duct the hot air from the CPU out the back of the
case. The idea of pulling hot air into the PSU isn't the best - just
easier.
 
You do NOT have a choice. The fan on the PSU MUST face down to pull the hot
air up and out of the case.
 
Noozer said:
Better yet... Specifically duct the hot air from the CPU out the back
of the case. The idea of pulling hot air into the PSU isn't the best
- just easier.
Click to expand...

Or, easier still, duct the fan *intake* so it gets cooler air from outside
the case. Very simple with most cases, you can even do what I did and add a
case fan to 'supercharge' the CPU fan. Just cut an 80mm (or 90, whatever)
hole directly above your CPU, fit case fan and grille, then fabricate a
tapered duct to within a few mm of the CPU fan (to allow for removal/fitting
the case side). Hot glue the duct to the case fan and Bob's your mother's
brother. You can even use a pretty multi-coloured LED case fan like I did
for my g/f's machine. Using stock (AMD) HSF's it drops die temps between
8-10°C, in the three caes I've done it. That's a bigger drop than most
'whizz-bang' $50 all-copper coolers will usually give you. All for about
$10, including getting the hole drilled.
 
Stupid question I'm sure but...

Have just bought a Nexus 3500 PSU. See http://www.nexustek.nl/nx3500.htm.

Can this be installed either way up, i.e. with the single big fan on top
or at the bottom? And if so which way is preferable? With the label the
right way up the fan would be at the top but the switch and socket is the
other way up and I thought having the fan at the bottom would stop the unit
filling with dust. Your advice appreciated.
Click to expand...

The screw layout doesn't leave you any options: Fan side down.

A poster in a previous thread noted that this psu leaked hot air into
the case. it would be interesting to find out if you see this effect
also, and whether you think it is significant and/or worrying...

Vic.
 
Vic. said:
The screw layout doesn't leave you any options: Fan side down.

A poster in a previous thread noted that this psu leaked hot air into
the case. it would be interesting to find out if you see this effect
also, and whether you think it is significant and/or worrying...
Click to expand...

Put it in this morning and as you say it will only go in one way - fan down.
I think them showing it the other way up in all the drawings and putting the
label upside down was just to confuse me. :)

Definitely haven't noticed any tendency to leak hot air into the case, in
fact a big bonus has been that the mobo/cpu temps have fallen from 31/52
degrees at best to 25/45 degrees now (ambient about 20). I can feel the
difference just laying my hand on top of the case.
 
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