Additional Cabinet Fans increasing Temp, Why?

[janitha]

In the latest Digit (or was it Chip) there is a small article showing the advantages of using additional fans and the reduction in temperatures obtained.

Seeing it, I added three fans to my system which had only the two fans in the SMPS in addtition to the HSF and chipset fans.

I added front inlet, rear exhaust and side inlet opposite to the processor. The rear exhaust is an Antec and the other two are ordinary Rs.70/- ones.

Surprisingly, the temps went up by about 3-4 degrees. More surprisingly the Mobo temp which used to be about 3 degree lower than the CPU is now about 3 degrees on the upper side.

What may be the reason?
Is it possible that the Cabinet is the culprit? It is an I Ball.

More importantly I would like to know another thing. In all the cabinets that I have seen, the front portion behind which we attach the front inlet fan is closed. So how the fan will be able to suck in fresh cold air as it is supposed to do.

Hope somebody will clarify. I hope that I will not have to remove the additional fans.
Thanks in advance

V.Prem Kumar

[kalpik]

Try reversing the direction of the fans. Make sure they are throwing air outside the cabinet, not inside.

[theraven]

the front isnt sealed
its meagrely closed
doesnt mean air cant get inside


yes sometimes the arrangement affects motherboard temps
the placements of the fans may lower cpu temps but in turn may blow that hot air it takes from the cpu on the motherboards heatsink hence increasing its temps..

is it ur cabinet ? yes partly .. but theres no way of tellin which cabinet would have what effect if u add ur own fans

[janitha]

Originally Posted by kalpik

Try reversing the direction of the fans. Make sure they are throwing air outside the cabinet, not inside.

The fans were fitted after doubly making sure about the directions.
V.Prem Kumar

[janitha]

Originally Posted by theraven

the front isnt sealed
its meagrely closed
doesnt mean air cant get inside


yes sometimes the arrangement affects motherboard temps
the placements of the fans may lower cpu temps but in turn may blow that hot air it takes from the cpu on the motherboards heatsink hence increasing its temps..

is it ur cabinet ? yes partly .. but theres no way of tellin which cabinet would have what effect if u add ur own fans

This is exactly what I had suspected. The side inlet fan throwing air onto the processor may be spreading the hot air over the Mobo.

But why the general increase in temp of 3-4 degrees instead of decrease?
Thank you both for the immediate response.

V.Prem Kumar

[ashnik]

hey what i-ball cabinet model...and make all fans exhaust

[Ashis]

Whats is UR SMPS power handling Capacity?
In watt?
RU OverLoading UR SMPS?

[janitha]

Originally Posted by Ashis

Whats is UR SMPS power handling Capacity?
In watt?
RU OverLoading UR SMPS?

SMPS wattage is 400 and it is really heavy. Amperage of the voltage rails are not specified. But the in use voltages are 11.968, 5.026 and 2.232 each and hence I think it is not at all overloaded

V.Prem Kumar

[theraven]

for best results u need a larger intake fan which would cover a larger area

i got stuc with a 90 mm
a 120mm side fan would give best results ..

i say leave it .. ur computer still runs happier

[janitha]

Originally Posted by theraven

for best results u need a larger intake fan which would cover a larger area

i got stuc with a 90 mm
a 120mm side fan would give best results ..

i say leave it .. ur computer still runs happier

Yes, but unfortunately my cabinet has provisions for 80 mm only. Otherwise I would surely have bought 120mm ones.

BTW about the side fan, should it be inlet or exhaust?

V.Prem Kumar

[theraven]

side fan should be "INLET"
but u can try reversing and checkin the results

mostly cpu fans blow air on the cpu
i was unsure abt this so i asked ard and checked on google
app there are some fans which blow air away
so it might be a good idea to check the directioon of ur cpu fan and match the side fan flow acc.
inlet to inlet or exhaust to exhaust


u may also be interested in moddin ur cabinet either to accomodate a 120mm fan or another 80 mm fan just below it to from a sort of ripple effect

[Ashis]

Originally Posted by janitha

SMPS wattage is 400 and it is really heavy. Amperage of the voltage rails are not specified. But the in use voltages are 11.968, 5.026 and 2.232 each and hence I think it is not at all overloaded

V.Prem Kumar

Yea....thats may not be the problem!
Try blowing the the two rear fan out of the cabinate!

[janitha]

Originally Posted by theraven

side fan should be "INLET"
but u can try reversing and checkin the results

mostly cpu fans blow air on the cpu
i was unsure abt this so i asked ard and checked on google
app there are some fans which blow air away
so it might be a good idea to check the directioon of ur cpu fan and match the side fan flow acc.
inlet to inlet or exhaust to exhaust


u may also be interested in moddin ur cabinet either to accomodate a 120mm fan or another 80 mm fan just below it to from a sort of ripple effect

I knew that my CPU fan blows air into the heatsink like majority of them do and that was why I fitted the side fan to blow in.

Anyway I changed the direction of the side fan and made it an exhaust. Now the temperature has come down somewhat and more importantly the Mobo temp is two degrees below the CPU temperature.

The lesson I have learnt is that in such cases trial and error is best. And maybe the cabinet is not good wrt airflow.

Thank you all for assistance and suggestions, especially theraven

V.Prem Kumar

[Tech&ME]

@

You should make the side fan as exhast (outlet) and remove the front inlet fan, the reason is simple , the front inlet fan only works if you are working in an airconditioned room. So, the inlet fan in the front will take the cold air of the airconditioner and push it inside your cabinet.

But it seems you are not working in an airconditioned room, so what is happening is the hot air is being pushed inside the cabinet which should not happen.

So, better remove the front inlet fan.

You can also put this fan as an outlet at the rear by modding your cabinet.

Remember : However, make all fans exhast (outlet).

This should work, please let us know.

[janitha]

Originally Posted by Tech&ME

@

You should make the side fan as exhast (outlet) and remove the front inlet fan, the reason is simple , the front inlet fan only works if you are working in an airconditioned room. So, the inlet fan in the front will take the cold air of the airconditioner and push it inside your cabinet.

But it seems you are not working in an airconditioned room, so what is happening is the hot air is being pushed inside the cabinet which should not happen.

So, better remove the front inlet fan.

You can also put this fan as an outlet at the rear by modding your cabinet.

Remember : However, make all fans exhast (outlet).

This should work, please let us know.

Thank you, but I have already done that (see my post 1 minute earlier) and it works.
My room is AC but I use it mostly when I go to sleep ( due to the Bill).
I will also try as you suggested, by disabling the front inlet or fitting it also as rear exhast.

V.Prem Kumar