Originally Posted by Guruboy
Unless it's being impeded, IOW the intake fans are pushing air in faster than the exhaust fans are getting rid of it. This means the actual pressure difference created by the intake fans is lower than it could potentially be with good enough exhaust. Fans don't just create an amount of pressure no matter where they are. In a closed system like a computer case, you need to have equal input and output to get the most out of the fans.
Only one semi-intake fan in this case: (don't see any air tube coming from 5.25" bays or elsewhere to CPU HSF or PSU)
And two exhausts, PSU and fan below it.
Those holes next to card slots are question mark, they might provide some fresh air for graphic card but they might also be airflow shortcircuit causing exhaust fan to draw air through them instead of just exhausting air already in case. So blocking that temporarily for seeing does airflow inside case change to better or worse would be sensible.
When talking about fan (unlike in case of free air movement) airflow and pressure aren't directly proportional but inversely proportional.
Generating higher pressure is same as lower airflow so your dream situation of fan generating maximum pressure is same as solid plate in front of fan and air not going anywhere.
Real specs of fans always include graph showing how airflow drops in relation to pressure generated for winning back pressure:
The ironic thing is that fan has to always generate some slight pressure because otherwise air wouldn't move at all.
Also this requirement of slight pressure for being able to push air forward means that if air is already traveling at rate fan could produce that pressure mostly disappears and fan can't give airflow any extra push but just "rolls on downhill/downwind".
Situation is quite similar to serial connection of batteries, with two batteries in series voltage (pressure) pushing current (airflow) doubles meaning same current can be pushed through double resistance but maximum current is still same as that of one battery.
Similarly second fan in series can only increase pressure for overcoming back pressure but not increase maximum airflow capacity.
So best solutions for more airflow is
- Minimizing impedance of exhaust/intake paths (case is rarely so cramped air wouldn't find low impedance route)
- Rising number of fans in parallel
- Increasing RPM of fans
Effective cooling is all about adequate airflow going through right places, not maximizing number of fans crammed into case.
Cooling of Sonata cases actually works well with negative pressure principle after airflow is controlled (did this for neighbour) with exhaust fans drawing air into case from front past HDDs. With side panel open HDDs just heat fast to very hot because soft mounting prevents conductive cooling.
Also huge amount of electric devices and parts use negative pressure cooling with just exhaust fan. Other end of casing has just intake holes and airflow between it and fan is controlled so that it goes past right places.
Working positive pressure cooling is similarly possible but it's much harder/requires much more careful control of airflow because unlike exhausts, intakes are generally far from components needing cooling and airflow can get lost to elsewhere.
It's just that Sonata has been designed as quiet basic case for basic computer, job which it fills well, (except CWT made PSUs of Sonata I and II were time bombs) and not for overclocked/overvolted CPUs and hot graphic cards.
Originally Posted by phillipjos
This is a "Quote" from another Fourum
Air being pushed past a fan actually HEATS it up.
In practise that would be more theoretical than real. Fans themselves produce very little heat/if heat production is big airflow is still bigger meaning rise of airflow T is insignificant. (and couple billion light years better than just passive convective airflow)
Sure heat is in principle movement of particles (in sense hottest place in solar system isn't Sun but Jupiter's magnetosphere which accelerates charged particles to huge energies equal to 300-400 million Kelvin) but speed increase provided by fan is insignificant.
Neither there's enough pressure for compressive heating: Volume/pressure of air parcel and temperature are closely related, rising pressure/compressing air parcel to smaller volume rises temperature and vice versa. (this pressure-temperature relation is what causes fog like condensation often visible in airshows around high performance aircrafts during maneuvers and ring/spherical like expanding clouds in nuclear tests)