Case Coooling Fans

  • Thread starter Thread starter George Hester
  • Start date Start date
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George Hester

So I need a fan for this machine. I measure from screw hole to screw hole
and I get 3.25 inches between them. So I go to the store. They say 80mm.
First off I don't know what that measurement means whether it is screw hole
to screw hole or the dimensions of the fan itself. So I go to eBay and I
find nothing at 3.25 but I do see 3.5. Is 3.25 not normal?
 
George Hester said:
So I need a fan for this machine. I measure from screw hole to screw hole
and I get 3.25 inches between them. So I go to the store. They say 80mm.
First off I don't know what that measurement means whether it is screw
hole
to screw hole or the dimensions of the fan itself. So I go to eBay and I
find nothing at 3.25 but I do see 3.5. Is 3.25 not normal?
Click to expand...
I'm pretty sure you are after an 80mm fan. Fan sizes tend to be metric, the
most frequently used in PC cases being 80, 92 and 120mm

HTH
SteveH
 
I wish that were true for what I have here. Since we got 2.54cm to an inch
and I have 3.25 inches that gives 2.54 * 3.25 ~ 8.255cm. That is 82.55mm.
So 80mm isn't going to cut it. This case was released in 1998.
 
George said:
I wish that were true for what I have here. Since we got 2.54cm to an inch
and I have 3.25 inches that gives 2.54 * 3.25 ~ 8.255cm. That is 82.55mm.
So 80mm isn't going to cut it. This case was released in 1998.
Click to expand...

I'm amazed that those people at the store gave you that kind of answer.
This isn't exactly rocket science. My system is a later year Compaq
Presario and measuring my case fan screw holes from the outside I got
the same 3.25" that you did. So I opened my case and measured and the
fan has a diameter of 80mm. Apples & oranges measurements. Go with the
80mm!

HTH
Bob
 
Alrighty now. There we go. So what is the 80mm meausring? Oh the fan
diameter. Well that makes a lot of sense. I never thought to meaure the
fan diameter because mounting it does not depend on the diameter of the fan
but the distance between screw holes. Thanks well back to the store they
weren't too much.
 
George said:
Alrighty now. There we go. So what is the 80mm meausring? Oh the fan
diameter. Well that makes a lot of sense. I never thought to meaure the
fan diameter because mounting it does not depend on the diameter of the
fan
but the distance between screw holes. Thanks well back to the store they
weren't too much.
Click to expand...


If your case has a grating of holes where you're supposed to mount the fan,
then you can screw in just about any square fan+frame setup that's less
than ~80mm (screwing it into corresponding holes on the grating). It will
be a bit easier if you use washers together with the screws.

As for your measurements, I'm fairly certain that industry standards for
case fan measurements are not stated accurately to the last place of
decimal which has not be a big deal, I added 4 case fans to my case in
recent weeks with no problems, and all my gratings measured 80+-5 mm...
 
George Hester said:
Alrighty now. There we go. So what is the 80mm meausring? Oh the fan
diameter...
Click to expand...


The 80mm is the outside dimension of the fan housing,
not the diameter of the spinning blades, nor the diameter
of the venturi or "throat". In short, it's the size of the thing
that has to be put in a retail package (excluding the power
cord). This dimension is about a cm bigger than the air
hole in the PC's case.

*TimDaniels*
 
George said:
Alrighty now. There we go. So what is the 80mm meausring? Oh the fan
diameter. Well that makes a lot of sense. I never thought to meaure the
fan diameter because mounting it does not depend on the diameter of the fan
but the distance between screw holes. Thanks well back to the store they
weren't too much.

George Hester
_________________________________
Click to expand...

Even though it looks now as though an 80mm won't do the trick, the
corollary to what I said is that you needn't be concerned about that
"1998". I bought my system last year and I see it often in ads, so it
appears that this model case (and fan?) is still being made. It could be
Compaq OEM and like nothing else, but who knows.

The external measurement is 3 5/8" x 3 5/8" (92mm), which must come
close to yours? The screw holes are the same as yours at 3.25" x 3.25".
The fan blades themselves are 80-85mm, but it's awkward getting in there
& being careful not to break anything and they don't enter the equation
anyhow.

The point being that you could do worse than check for replacement
Compaq parts to find one.

Bob
 
Cooling fans for computer cases are measured in the industry in metric
terms: mm and cm; not inches.
 
Robert Heiling said:
Even though it looks now as though an 80mm won't do the trick, the
corollary to what I said is that you needn't be concerned about that
"1998". I bought my system last year and I see it often in ads, so it
appears that this model case (and fan?) is still being made. It could be
Compaq OEM and like nothing else, but who knows.

The external measurement is 3 5/8" x 3 5/8" (92mm), which must come
close to yours? The screw holes are the same as yours at 3.25" x 3.25".
The fan blades themselves are 80-85mm, but it's awkward getting in there
& being careful not to break anything and they don't enter the equation
anyhow.

The point being that you could do worse than check for replacement
Compaq parts to find one.

Bob
Click to expand...

Now whatever made you think of Compaq? As it is you are right. Now I don't
feel so confident anymore. I actually have a fan I can put in that measures
correctly. And it does have the right kind of power connection. The one in
the store had what looked like three different types of Power connections.
I really don't want to deal with all those Power connections so I'm just
gonna hit a used computer store on Tuesday.
 
George said:
Now whatever made you think of Compaq? As it is you are right.
Click to expand...

As I had mentioned, my system here is a Compaq Presario. Sounds like
yours is Compaq also then, only a 1998 model. Perhaps the fan is Compaq
proprietary then.
Now I don't
feel so confident anymore. I actually have a fan I can put in that measures
correctly. And it does have the right kind of power connection.
Click to expand...

Why in the world wouldn't you use it then?
The one in
the store had what looked like three different types of Power connections.
Click to expand...

But I thought those were all 80mm and wouldn't fit the screw holes.
I really don't want to deal with all those Power connections so I'm just
gonna hit a used computer store on Tuesday.
Click to expand...

Bob
 
As I had mentioned, my system here is a Compaq Presario. Sounds like
yours is Compaq also then, only a 1998 model. Perhaps the fan is Compaq
proprietary then.
Click to expand...

No, Compaq does not use proprietary fans, not on any models
for this purpose. It (all of them) are a standard fans
coming in standard conventions for size, speed (or current
rating is used if no fan spec can be found to compare) and
connector.

But I thought those were all 80mm and wouldn't fit the screw holes.
Click to expand...

It is common that retail stores, even computer stores and
shops, may have poor selection of fans, and often low
quality, or overpriced, or both.
 
kony said:
No, Compaq does not use proprietary fans, not on any models
for this purpose. It (all of them) are a standard fans
coming in standard conventions for size, speed (or current
rating is used if no fan spec can be found to compare) and
connector.
Click to expand...

That's what I would have guessed at first since it would be a silly
thing to make proprietary, but nobody was mentioning a fan measuring
92mm x 92mm, even the OP, although someone else mentioned size of retail
It is common that retail stores, even computer stores and
shops, may have poor selection of fans, and often low
quality, or overpriced, or both.
Click to expand...

Fans or personnel? Sure, but when they're dealing in that sort of thing
on a daily basis, you'd think they would say simply that they don't
stock that size and try Joe's down the street for that one. As I said
before, it ain't rocket science.

Bob
 
I didn't want to use it because it was planned for another computer I am
building. It's a Compaq Deskpro SB/EB somthing like that. A PII 300MHz.
Not real fast but takes any operating system I can throw at it. So I use it
for my Domain Controller and has done well except for a few issues. Like
the BIOS only sees max 60GB drive. I have a 120GB disk in it but I cannot
use a 3rd party Disk Management app on it unless I remove the drive first.
Then I can.

I'll probably just go down to the used Computer store. They have fans with
no bells and whistles. The one at the Retail Store Staples even had what
looked like a 12V connector. Why the hell I'd need a 12V connector for a
fan is beyond me but the wires from the fan there were three connectors at
the end of it. When I look at mine it's pretty darn simple. One connector
and fits where it should go.
 
George Hester said:
So I need a fan for this machine. I measure from screw hole to screw
hole
and I get 3.25 inches between them. So I go to the store. They say
80mm.
First off I don't know what that measurement means whether it is screw
hole
to screw hole or the dimensions of the fan itself. So I go to eBay
and I
find nothing at 3.25 but I do see 3.5. Is 3.25 not normal?
Click to expand...


Measure the width of the fan casing, not between the mounting holes. An
80mm fan is 80mm wide (or 81mm). The mounting holes are 72mm apart.
The fan size isn't the distance between the mounting holes. It is the
size of the fan itself (i.e., how much space you need to insert the
entire fan assembly). Besides width, you also need to consider the
thickness of the fan. You can get 15mm, 25mm, and 30mm thick fans.
Check your clearance since putting in too thick a fan means it won't
have the necessary clearance.

If you are measuring 3.25 inches between the holes (and presumably you
are measuring from same edge to same edge across the holes) then they
are 82.55mm apart which already makes it larger than an 80mm fan. So
you need a 92mm fan (sometimes also called a 90mm fan).

You could always visit some fan manufacturers to see their
specifications for their fans which include dimensions. For example,
looking at a Panaflow 80mm fan
(http://www.panasonic.com/industrial/appliance/pdf/fans/m/fba08a.pdf),
the fan case is 80mm wide and the holes are 71.5mm apart. For their
90mm fan
(http://www.panasonic.com/industrial/appliance/pdf/fans/m/fba09a.pdf),
the case is 90mm wide and the holes are 82.5mm apart.
 
George Hester said:
I didn't want to use it because it was planned for another computer I am
building. It's a Compaq Deskpro SB/EB somthing like that. A PII 300MHz.
Not real fast but takes any operating system I can throw at it.
Click to expand...

Tried Windows XP?

So I use it
for my Domain Controller and has done well except for a few issues. Like
the BIOS only sees max 60GB drive. I have a 120GB disk in it but I cannot
use a 3rd party Disk Management app on it unless I remove the drive first.
Then I can.

I'll probably just go down to the used Computer store. They have fans
with
no bells and whistles. The one at the Retail Store Staples even had what
looked like a 12V connector. Why the hell I'd need a 12V connector for a
fan is beyond me but the wires from the fan there were three connectors at
the end of it. When I look at mine it's pretty darn simple. One
connector
and fits where it should go.
Click to expand...

By 12v connector, I presume you mean a 4 pin Molex. Fans often come like
this, as they are indeed 12v and this allows them to be connected straight
to the power supply in the event of thee being no connectors available on
the motherboard for them.

SteveH
 
ditto..

if you find this stuff confusing then i pray for you, you're gonna have
a hard time dealing with computers ;)
 
You know something SteveH. I need a 4-Pin connector. That goes into the
Motherboard. But all the fans I have seen are 3-Pin. I don't think this
type of connector is called a Molux though. I'm pretty sure you mean like
the Power connectors for IDE drives. Yes the one in the store has that but
I believe that is only for the bells and whistles; it lights up the inside
of the case with a blue LED. It can attach with just a 3-Pin connector too
bad my Motherboard wants a 4-Pin connector. This little project is going to
take weeks it seems.
 
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