i was thinking about ducting cold air from outside directly onto my heatsink. i found some nice 80mm ducting, but i have a 120 mm fan on the heatpipe (xp120) im gonna be installing. i wanted to put a 120mm fan on either end of the duct to really get the air moving. my question is this, since the ducting is 80mm, if i were to use a 120mm to 80mm adapter on either end so it looks like: 120mm fan > 120 - 80 adapter > ducting > 80 - 120 adapter > 120mm fan will there be a decrease in performance because of the change from 120mm to 80? i realize that on the intake end, more air would be getting forced into the smaller ducting, but what about the exit end? what happens there? anyone done this?
What actually turns out most effective in most cases is if you mount a fan onto the heatsink where it is "sucking" air off the sink (as opposed to blowing air onto the sink) and duct the air coming off the fan to the outside of the case. The premis is that although you are using air inside the case to feed the sink, you are expelling almost all of the hot air being produced to the outside of the case. A lot of people have done it with great results. The only catch is that typically the sink gets jammed up pretty fast with dust since so much of the air is inside the case is being channeled right through it. But if you filter all your inlets for air on the outside of the case, you can minimize that effect. Besides, if you duct it straight from the outside to the sink like you initially describe, dust is probably going to be a problem there too. As far as using the 80mm ducting, I don't think that would be much of a problem. If you consider that a large portion of a fan's working surface is the hub which doesn't move any air at all, 80mm should be fine. Smaller than that and the ducting could prove to be a bottleneck.
thanks for the tip eddie, but the the reason i want it to come in from the outside is i have a antech trueblue 480 psu, which has a fan on the bottom of the psu. this blows right down on top of the heatsink that is installed there now. its a real tight fit too, so i was gonna do this until i had a bit of time on my hands to really work things over. id like to duct the PSU heat directly out, but dont know if i have enough room to do that.
It would definitely work, just make sure you use the same kind of fans for each side of the duct. Or one fan would push/pull the other fan. The fan on the intake should make up for any losses that would occur from the duct. The duct would make the air increase in velocity through the duct, and on the other side it would slow back down, and the fan would help disperse it and push it through the heatsink. Another thing you may want to consider, rather than ducting air to the CPU, duct the air from it straight to the back of the case. That way it dosen't even get a chance to recirculate or make anything else warm. Or do both.
i wanna do both, duct cold air to the cpu, and the hot psu air out. ill have to come up with something cleaver though, there isnt much space between the psu and the heatpipe. so itll need to be low profile. i got a couple ideas, but not sure as what to do yet. one option is inverting the psu so the fan blows up, then make a blow hole on the top of my case, but i need to make sure i could re-attach it good enough. ill eventually come up with something, i just need some "tinker time," which i SO dont have right now.
Yer psu seems a bit odd...in my expirence the fan that you say is blowing on yer cpu would be in fact sucking air into the psu and blowing it out the back something seems to be a lil off mabey you could open the psu and flip the fan so its sucking air in and and then out the back as it should already
here,you can blow and suck hot and cold air over the cpu, fan>filter>duckt>cpu>duckt>filter>fan. at least I think that should do I only put the filters there for the dust.
Yeah, if your PSU is blowing air into your case it's definitely not correctly made... it should be sucking air from the inside of the case and expelling it out of the back... You're SURE that this PSU fan is blowing hot air into the case? If so, just open the psu up and flip the fan around (Disclaimer: be careful here, I will not be held responsible if you get nipped by a capacitor)
yeah, the psu blows out the back and out the bottom, and both are pretty warm. ive never had a psu with multiple fans, so i dont know what to expect. maybe tomorrow ill give antech a call and see if it was designed this way. jtggg: with an xp120, its gonna be near impossible with the space i have to work with to get a duct on both sides of the thing.
If i get you right u want the case to have no affiliiation with the air going on the cpu. You want air going from directly outside to blow on cpu and air from cpu directly out of case. That is a nice idea and rly would be that hard. Your best bet wouild be hook a duct up to your cpu fan then go directly out then if your good use some aluminum or somthin put around an inch around heatsink (space aroun heatsink) then box all around it and have an opening that sipons air to a duct and out of the case. Sry if my idea is hard to follow if you would like i can draw a picture of it later on.
Check the air direction with a piece of paper. Sometimes it's difficult to tell with a low flow fan and unless you have a mismade PSU, it should be sucking. If you can reverse the flow if it is indeed blowing air onto your CPU then it will really help your temparatures. Oh, and does the diagram you drew have a filter on the outlet? Shouldn't need one if it is indeed, an outlet. Hope I can help
hmm, personally i think having cool air from outside the case is will give better temps.. since the air is constantly cooler over the cpu.. despite system temps (to a degree.. you may argue the duct gets warm but come on).. my config would be Wire fan filter (easy to hoover)>120mm fan>adapter>duct>adapter>120mmfan>xp-120 also.. that psu should definetly be sucking air from in the case.. if it isnt .. change it and.. balance the airflow.. this will broing the system temp down.. but remember, the cpu fan now counts as intake
uh, not exactly. i want cold air ducted right onto the cpu. after that, itll just dump into the case. i dont need to duct it back out. well, i called antec, and they say it should be sucking air into the psu. and again told me to check with a piece of paper.....uh, i guess i was wrong, the paper (barely) gets stuck to the fan grill. it really weirds me out though, cause there is a LOT of air coming down out of the psu right on top of my hsf.
