mobius

i am drawing up plans for a cusom rack that i am going to build for my amps where the backseat is. My amps get hot as is right now, but I plan on enclosing them in plex and wood. That cant make it any cooler on them. I want to get 2 fans (one to pull air and one to push air). what power source can I hook them up to and how much are these typically?

rcurley55

Ren them off of a fused 12V line from your battery. Use your amp remote wire to turn on a relay...use the output of your relay to turn on the fans and the amps. That's the safest way to go about it.

Runing a push/pull config is a waste of time and money. If your amp rack is really sealed, then you only need fans on the exit or entrance...I like to pull air across. If you have extra money, throw the other fans in there, again waste of money.

If you want more info, go here:
http://www.eatel.net/~amptech/elecdisc/

Some excellent info on relays, fans and ampracks is located there.

mobius

like if i put a fan at one end of the amps and the other at the other end to create a crossbreeze. i guess that would clarify.

thanks for the info.

rcurley55

just so long as you know that two fans in a push pull config do nothing to increas the amount of air you are moving across the sinks....

mobius

yeah, that is kind of the point, right?

rcurley55

I'm not sure what you are alluding to here.....

From a fluid mechanics/heat transfer stand point, there is no benefit to running a push pull type of config.

It would be more beneficial to use two fans in a pull config over using those same two fans in a push/pull config. You will get better heat transfer and will flow more air using the two fans together rather then pushing and pulling.

This is of course assuming that you have a relatively normaly shaped amp rack (a rectangle), it's fairly well sealed, and lastly, the inlet to the amprack is free of obstructions.

You will gain no "crossflow advantage" if you throw one fan at one end pushing and another fan at the other end pulling.

mobius

hmm, that is good to know. would you put the fans next to each other or one in a separate chamber on the same side of the amps to draw more air out. it won't be sealed, per say, but there will be no obstruction to the amps. in order to get a flow, there has to be at least an opening on the one side and a fan at the other side.

rcurley55

totally depends on the amps, the shape of the rack etc....if you want draw up something in pshop or paint and email it to me...I'll take a look at it and recommend something.

b00gers

i dont get that...

if you have a sealed box for the amps, having a fan push air out wont work.

where would all the "new" air come from? since the box is already filled with air, all the fan is going to do is create a vacumm and suck the air out. theres no inlet for "new" air to come in.

if you have a sealed box, with 1 fan on one end pulling air in, and another on the other end pulling air out...that would be a better config. since the heated air will rise from the amp, and be sucked out by a fan. and at the same time more air will come in. the air coming in would be naturally cooler than the air on top of the amps.

im just taking what i know from putting fans in my computer case.

you want the same amount of air going in, and going out. so look for fans that have a the same CFM rating.

i bet you can even use computer fans, good quiet ones go for no more than $20 each.

b00gers

it doesnt have to increase the amount of air moving across the amp, just as long as the heated air is moving out the box.