cocktail cab fan placement and air direction question

[quarterback]

I have a midway-style cocktail cab and two 120mm fans.  My thought is to put one of them in the bottom of the cab (facing the floor) and the other on the back of the cab (in the portion that flips back/horizontal when you open the cab up.

My plan is to have the fan in the bottom of the cab blowing out and the one on the back of the cab blowing in.   The one in the back will be blowing outside-air onto the monitor (the hottest thing in the cocktail) and the one on the bottom will then (hopefully) be blowing the interior-air out, towards the floor.   For those who aren't familiar, these cocktails sit slightly above the floor, so the base of the cab isn't resting on the floor itself.

The other option I thought of was to put both fans on the back of the cab with one blowing out and the other pulling air in.   The thing is, there's just not that much airspace between the back of the cab and the monitor itself.  There's much more free/open space underneath the monitor which is why I thought I'd put one into the 'floor' of the cab.

I know that others have contemplated this before, because cocktail cabs are notorious for building up heat.   Any major flaws in my fan placement idea?

[spacies]

This is a good question.
I have been thinking about fan placement a bit lately but like you said, there isn't much room for placing fans too high in the cabinet.

I can see the positives of both installations but I have always been a little sceptical about bringing the outside world of dust into my cabinets with a fan that sucks air in.

It would be interesting to see some temp results with fans in different places but i don't have the equipment to do that.

At present all my cocktails have the fan at the bottom of the cabinets, facing forward, blowing the air out. Its probably the least effective place to put them but there isn't many options because of the 20" tubes and the locks above the coin door. I could put them facing the players but again, it isn't right. My Defender style cocktails are sweet because there is just sooo much more room.









So as you can see my fans are more looks and less for functionality.

[ahofle]

I would think having the fan at the bottom like that would be just fine, provided you have some way for the air to enter at the top (preferably the other side) to create a flow inside the cabinet.  I think that flow would more than compensate for heat's tendency to rise.

[quarterback]

At present all my cocktails have the fan at the bottom of the cabinets, facing forward, blowing the air out.

WOW!  That's an impressive collection!

I would think having the fan at the bottom like that would be just fine, provided you have some way for the air to enter at the top (preferably the other side) to create a flow inside the cabinet.  I think that flow would more than compensate for heat's tendency to rise.

That's my thought as well.  I've read the other threads here about fan placement, and some suggest putting the 'out' fan higher.  But these cabs are so full inside, I'm really not sure it matters.

Other people have used the speaker ports (or just the grills where the speakers would be) to hide their fans, giving some kind of cross breeze.   That wouldn't really work with my current setup, so I think I'm just going to try the 2 fans.  One blowing-out in the bottom and one blowing-in on the back.     

I hesitate to do it the other way because I don't want to be sucking dust up into the cab off of the floor.  Also, it'll be much easier for me to clean dust off the fan in the back than it would be for me to clean the one on the bottom, so I'd rather it be blowing out.

[spacies]

Good call.

I wouldn't want to be sucking crap off the carpet into the cabinets. You just need to take a look at fans on the CPU or power supply on a PC and you will see how much crap is floating about in the air in any house!

I can see how the idea of 2 fans would keep things chilled but not sure if they are both required. If you have them, then use them otherwise I reckon the vents to suck in outside air and the fan to blow out the hot stuff would be fine. The fans I use are wired to the 12V PSU for the game board. Fans running off the mains supply would probably be a better option but you cant get them in blue 

As for the collection, thanks 
I have built them all from scratch. Have loads more too. We had an arcade when we were young and I love these old games. So I am always wheeling and dealing these things.

Heres some more I have done recently.

http://www.picturetrail.com/gallery/view?p=999&gid=5432451&uid=2715941&members=1

[danny_galaga]

I hesitate to do it the other way because I don't want to be sucking dust up into the cab off of the floor.  Also, it'll be much easier for me to clean dust off the fan in the back than it would be for me to clean the one on the bottom, so I'd rather it be blowing out.

ahhh. i was going to suggest the bottom fan suck. which is what mine does. i had never thought about the problem of dust. doh! of course, my house is cleaner than a hospital 

[quarterback]

of course, my house is cleaner than a hospital 

Maybe that's because your cocktail acts as a full time vacuum cleaner? 

[spacies]

HA HA HA HA HA

[torez]

WTF, just lost lengty post trying to submit it:(.

Anyway, would recommend the top fan to blow air out, as the air is the hottest there.  You don't want to work against the free raising hot air in your table.  Your cold air intake should be the closest to the floor, as it's the coldest there.  You could use both fans to blow out, as long as you have some intake holes in your box, but what's the point of sucking colder air out from the bottom anyway?

If you would go with the bottom fan as intake, you could try using a mesh filter (looks bit smaller than the stuff on screen door or similar).  I have that in my Antec P-160 computer case and it works pretty well.  Have to clean the dust from it every month or so.  The more/bigger fans you have the lower rpm you can put them on, resulting in less noise.  Good quality/quiet fans cost bit more, but are worth in the long run.  The same with quiet power supply.  Constant hum from all these noisy fans is definitely annoying, so this would be money well spent.

Mark

[danny_galaga]

WTF, just lost lengty post trying to submit it:(.

Anyway, would recommend the top fan to blow air out, as the air is the hottest there.  You don't want to work against the free raising hot air in your table.  Your cold air intake should be the closest to the floor, as it's the coldest there.  You could use both fans to blow out, as long as you have some intake holes in your box, but what's the point of sucking colder air out from the bottom anyway?

If you would go with the bottom fan as intake, you could try using a mesh filter (looks bit smaller than the stuff on screen door or similar).  I have that in my Antec P-160 computer case and it works pretty well.  Have to clean the dust from it every month or so.  The more/bigger fans you have the lower rpm you can put them on, resulting in less noise.  Good quality/quiet fans cost bit more, but are worth in the long run.  The same with quiet power supply.  Constant hum from all these noisy fans is definitely annoying, so this would be money well spent.

Mark

this is why i did mine that way. you know, i think i would again because there seems to be less dust at ground level than in the air...

[Level42]

I would think having the fan at the bottom like that would be just fine, provided you have some way for the air to enter at the top (preferably the other side) to create a flow inside the cabinet.  I think that flow would more than compensate for heat's tendency to rise.

You are completely working against nature this way. Hot air rises. Cabs (yes cocktails too) use this effect (chimney effect) to cool the parts like Power Supply, PCB and monitor. There's holes on the underside to let in air, and holes near the top to let it out. Because of the build-up of heat, the air will start to rise, exiting through the top holes. This automaticaly draws in cool air from the bottom holes that will transport through the cab and take up heat from the parts etc. etc.

This is usualy enough for cabs with real arcade PCB's. I'm hoping to MAME my cocktail fan-less, because I hate the noise. Since I probably will only play (very old) vertical games on it, I will use a very old mobo, which I may underclock and see if I can run it with coolers without fans.

[ahofle]

I would think having the fan at the bottom like that would be just fine, provided you have some way for the air to enter at the top (preferably the other side) to create a flow inside the cabinet.  I think that flow would more than compensate for heat's tendency to rise.

You are completely working against nature this way. Hot air rises. Cabs (yes cocktails too) use this effect (chimney effect) to cool the parts like Power Supply, PCB and monitor. There's holes on the underside to let in air, and holes near the top to let it out. Because of the build-up of heat, the air will start to rise, exiting through the top holes. This automaticaly draws in cool air from the bottom holes that will transport through the cab and take up heat from the parts etc. etc.

We're only talking about thermal convection here, not a tornado or hurricane.  All I'm suggesting is that the air current generated by a small fan is more than enough to move the hot air down and out if you are unable to find a suitable location for a fan near the top of the cocktail (which is what the OP mentioned).