Any horror stories from not properly ventilating a MAME cabinet

[Donkbaca]

I've never seen a pc or other electronic device that blows air in, they all exhaust. But people over build their mame cabs all the time

[SavannahLion]

For what it's worth every single audio install I have seen and or worked on pulls cool air in from the bottom [with a fan] and lets it out through the top. And I am talking amplifiers, tube equipment etc - the hot stuff. I have never seen one installed with fans pulling air out from the top. Though it would work, maybe it wouldn't be as effective. I don't know the science behind it.



A pc though? I think adding some fans and or vents is more for piece of mind than really a requirement.

What you're describing is a positive pressure system. This is where air is forced into the um... "container" and the exhaust is passive. A negative pressure system is where air is forced out of the container and intake is passive. What you're trying to accomplish determines what type of system you use. Grocery stores use air curtains creating a pseudo positive system to keep flying bugs out. A hospital might use a negative air system to help keep airborne disease inside and to help in a quarantine situation. Most PCs are negative systems (Donkbaca, is correct. IIRC early AT specified intake fans on the PSU ATX changed this to exhaust to... no idea why....) but, IMHO, a positive system is better since it precisely allows you to control intake points and thus, add dust filters.

I've installed fans in both directions as well but I've always leaned towards forcing more air inside than drawing more out.

[Donkbaca]

The reason they exhaust is because the point of the fans is to remove heat, not intake air. The pc doesnt need air to function. If you blew air in and just let it leak out, you run the risk of heat building up as all you are doing is recirculating hot air around the case.  The heat sinks radiate heat away from the circuits, warming the air around them the fans blow this hot air out. If you had fans blowing in, you would be blowing this hot air right back on the circuits until it found a way to escape 

[leapinlew]

Dude I've played arcade games for more than 30 years and repaired 'em for 20. Its not my top priority in life. Why do you care so much that I want my stuff to last? I'll do it the way I want to, so quitchabitchin.....

You can build a fire in your nifty MAME cab for all I care.....

You've been playing and repairing arcade games for a long time. Big whoop. Who here hasn't.

I was just giving you grief. 

[SavannahLion]

The reason they exhaust is because the point of the fans is to remove heat, not intake air. The pc doesnt need air to function. If you blew air in and just let it leak out, you run the risk of heat building up as all you are doing is recirculating hot air around the case.  The heat sinks radiate heat away from the circuits, warming the air around them the fans blow this hot air out. If you had fans blowing in, you would be blowing this hot air right back on the circuits until it found a way to escape  

Sounds to me you're assuming traditional placement of the fans. It would be absurd to draw air IN at the top and expect enough hot air to exhaust at the bottom. Intake fans are placed at the bottom section of a case, vent the top, as long as you avoid a short circuit, you get your air circulation and vent the hot air.

In any case different methods anyways. I use what I need to use.

The way OEMs cut corners with a single case fan (and through the PSU no less) is almost comical.

[Donkbaca]

why do you need to draw air in?  I don't think you are using what you need to use, I think you are using what you want to use.  Its funny that tech companies spend millions of dollars designing their products, with things like heat dissapation in mind, and we figure that we need to add a 10 dollar fan to keep everything from going super nova....

If it makes you feel better, put a fan in.  Its kinda like a night light, it keeps the pretend boogey men away.  Doesn't actually help anything, but if it makes you feel better, go for it.

[bkenobi]

why do you need to draw air in?  I don't think you are using what you need to use, I think you are using what you want to use.  Its funny that tech companies spend millions of dollars designing their products, with things like heat dissapation in mind, and we figure that we need to add a 10 dollar fan to keep everything from going super nova....

If it makes you feel better, put a fan in.  Its kinda like a night light, it keeps the pretend boogey men away.  Doesn't actually help anything, but if it makes you feel better, go for it.

Interesting.  I'm a thermal analyst for a multi-billion dollar international company.  This is what I do.  I guess what I do is funny?

Heat concerns are real and justified, but you have to understand what the goal is.  In this case, we have a relatively small heat source in a large air space.  If the air starts out cool, even if there is poor ventilation, we will still be able to use the PC for quite a while before there is an issue.  If there is designed ventilation, all it has to do is remove more heat than the system is adding.  There are local effects that could cause issues, but in general that's the goal.

Modern consoles and laptops have a lot of heat generated with very small air space.  As a result, they MUST control their thermal environment.  The easiest/cheapest thing to do is to put a heat sink on the chips that generate heat.  In the case of these small environments, there isn't enough thermal mass in the air to keep things cool for very long.  Thus, they add fans (either intake, outlet, or both) to get fresh ambient air into the case.

In the end, essentially all thermal problems can be solved by providing a large enough deltaT!

[Vigo]

My 2 cents is just have a few air holes and you are more than good. If overheating was such an inevitable issue in a large closed space, you would see a standard of fans mounted on the backs of every armoire style TV cabinet. All their recommendations simply just say to leave a few inches clearance around your different devices and give them room around their ventilation to individually cool themselves. I'm sure if you had 5 hot devices all crammed together in a closed shelf of an armoire, it might have heat issues, but those cases are not common to the normal user.

Something like 1 computer in the bottom of a 5 foot tall wooden box with gaping holes is not a major concern. Otherwise I would feel a temperature rise when i open the back of of my cabinet. somehow its the same temp as outside my cabinet.

[Donkbaca]

AHA!  Why are companies spending so much money hiring people like Bkenobi when any jackass just needs to add fans!  Stop screwing us on OEM corner cutting Bkenobi! We want to feel the breeze coming off our electronics.  I expect my entertainment center to cause a damn mini hurricane when I am running all of that stuff!

[Vigo]

AHA!  Why are companies spending so much money hiring people like Bkenobi when any jackass just needs to add fans!  Stop screwing us on OEM corner cutting Bkenobi! We want to feel the breeze coming off our electronics.  I expect my entertainment center to cause a damn mini hurricane when I am running all of that stuff!

Obviously, by his namesake, we can infer that bkenobi went into thermal engineering in order to design thermal detonators. I'd be careful about that next electronic device you purchase.

[leapinlew]

AHA!  Why are companies spending so much money hiring people like Bkenobi when any jackass just needs to add fans!  Stop screwing us on OEM corner cutting Bkenobi! We want to feel the breeze coming off our electronics.  I expect my entertainment center to cause a damn mini hurricane when I am running all of that stuff!

Obviously, by his namesake, we can infer that bkenobi went into thermal engineering in order to design thermal detonators. I'd be careful about that next electronic device you purchase.

Bkenobi can't do anything to me. I live in a moon-sized space station with only 1 small vulnerability.

[CheffoJeffo]

Out of the cabinets that I have had, only two have had fans -- a bartop and a homebrew Midway-styled cocktail, both due to heat from the monitors. No other cocktails and none of the uprights have ever needed a fan.

[bkenobi]

AHA!  Why are companies spending so much money hiring people like Bkenobi when any jackass just needs to add fans!  Stop screwing us on OEM corner cutting Bkenobi! We want to feel the breeze coming off our electronics.  I expect my entertainment center to cause a damn mini hurricane when I am running all of that stuff!

Ever hear that joke about consultants?

A consultant is hired to fix an expensive piece of machinery.  He examines the setup for a bit and after 10 minutes takes out a marked and puts an 'X' on a part.  He turns to the manager and says "replace this part."  A couple days later the bill for the consultant shows up.  The manager is outraged to see a single figure of $50,000!  He calls up the consultant and asks for an itemized bill.  A couple days later a new bill shows up with items called out.

Marker..............................$1
Knowing where to place the mark.....$49,999

The bill was promptly paid.

 

Anyway, I would love to do that with fans, too!

[SavannahLion]

That's weird. Had a nice long post and I got logged off with an invalid cert. Now some of the thread is missing

[saint]

That's weird. Had a nice long post and I got logged off with an invalid cert. Now some of the thread is missing

Looks OK to me?

[SavannahLion]

Thought maybe you messed with the thread?

[markronz]

So I guess the answer is no, there are no horror stories.

I once dug up an old arcade cabinet that I found buried in my backyard.    I spent the better part of a week fixing it up, getting that old beauty whirring again.   Finally the moment was at hand, I plugged it in.    Rather than the standard BIOS screen to celebrate my success, I was greeted by a...um...cursed circle thingy...

Cursed Circle Thingy...

Chills went through down my spine.  Soon after the video completed, I received a phone call.  The crackly voice at the other end of the line just said "two days..." and hung up.   I spent the next 48 hours digging through old microfiche newspapers at the library, trying to find something that would help, anything to explain this madness.   47.5 hours into my search I found the article...."Cursed arcade machine buried in ancient Indian burial ground!"  I immediately called the police and frantically tried to explain what was happening...to no avail.  They did not believe me.   I sped home, at high speeds, narrowly avoiding car accident after accident.   I ran into my house, just as the phone rang.   I answered the phone, slowly putting the receiver to my ear.   To my horror, I heard screeching, wild noises, of animals being tortured and nails being dragged slowly down chalk boards.   I immediately hung up.   The phone rang again!  I picked up and screamed "Why are you torturing me!   I just want to play space invaders!...maybe a little NBA JAM, if there's time!"   A voice yelled through the line "Mark!  Mark!  This is the police!  We traced the call, and it came from....INSIDE YOUR ARCADE MACHINE!"     I immediate opened up the access panel behind the cabinet.   Inside, on top of the computer, was only a note...  It read....

Sup Mark, I'm the creepy evil spirit thing, that's hell bent on creeping you out 'n' stuff.   You like totally saved the day, I just realized that you installed some exhaust fans in here.   I feel soooo much better now, thank you for doing that.   I wasn't really cursed, I was just like hot in here.

The End.  Crisis averted.  Exhaust fans worked for me.  

[ChadTower]

Interesting.  I'm a thermal analyst for a multi-billion dollar international company.  This is what I do.  I guess what I do is funny?

NSFW

The Goodfellas - Funny how??

[Gray_Area]

I have normal CPU cooler and case fans on the PC in my cab.  Small air vents in the cabinet.  The cabinet sits in my garage where temps during the summer hit 115f degrees...  I've had no issues in 5 years.  Of course the PC has been upgraded a couple times in 5 years, but still no issues.

It wouldn't be turned on, because I sure wouldn't be out there playing it at that temperature.

If adding fans, put them at the top. It's easier to pull air in than force it in, and you get greater exchange. Or another way, notice PC case fans blow out?

[Donkbaca]

Any horror stories of someone over ventilating their name cab?

[eds1275]

Any horror stories of someone over ventilating their name cab?

I like to think my cab is pretty cool as it is!

[Paul Olson]

I had a core2duo in mine, and my overclock was definitely affected by being in the cab. Outside of the cab, I was a little over 4GHz, but could only keep it stable at 3.6GHz inside the cab. I don't know if a fan would have helped though. It stayed at a pretty constant temp though. the computer was on for months at a time (turned off the arcade monitor when not in use though), and never had any issues.

[bkenobi]

Some fans blow some suck.  The fans at the back of your system (PSU and system fans) are typically designed as exhaust fans.  They suck air OUT of the case out into the room.  Fans on the front of a case (hard drive coolers for instance) are typically going to blow air past the HDD  INTO the case.  As far as heat transfer goes. both methods work equally.  This is convection and the primary drivers in that form of heat transfer are flow speed and delta temperature.  The equation is:

q=h*A*dT

where,
h = film coefficient (driven by flow speed, geometry, etc)
A = surface area
dT = difference in temperature between air and surface temperatures

The direction of the flow makes little difference (it's factored in with h, but a forced convection flow is really independent of what direction the flow moves).  The area is pretty important, obviously, but it's set by the hardware in the system.  The delta temperature is also critical as you get no heat transfer if the air inside the case is the same as the component being cooled.  Increasing the velocity is good, but can make for more noise which is potentially bad.

Anyway, my point is that whether the fan blows air in or sucks air out, it really doesn't make as much difference as you would think.  Now, if I were designing the flow, I'd use exhaust fans or else add fans pointing at components to make sure there was forced flow in those areas.

That'll be $50,000.  Who should I send the bill to?   

[Vigo]

Some fans blow some suck.

Not to be nitpicky, but don't all fans suck and blow at the same time? I get that some fans are designed to blow, and some were born to suck, but to get things flowing, a fan has to always suck from one end and blow on the other end. It's just kinda basic physics.

OK, this post is sounding very, very wrong. I better stop right now.  

[Donkbaca]

Who needs physics when you have consultants? I let them handle all the sucking and blowing and just sit back and enjoy their work...

[TOK]

That'll be $50,000.  Who should I send the bill to?  

Maybe someone who lived in the 1500's? I don't know who else doesn't already know fans cool things.  

[TOK]

Uhm, fans don't actually cool anything.

[boardjunkie]

Hah....right. The fan itself don't cool things, the air it moves does. I guess you could say it indirectly cools components.

But....its a stupid idea to use a fan in your game cabs so don't bother...

[SavannahLion]

Some fans blow some suck.

Not to be nitpicky, but don't all fans suck and blow at the same time? I get that some fans are designed to blow, and some were born to suck, but to get things flowing, a fan has to always suck from one end and blow on the other end. It's just kinda basic physics.

OK, this post is sounding very, very wrong. I better stop right now.  

In a general sense yes, but there is some physics and installation considerations that govern this frame of logic. Namely, that air is lazy as it moves about.  In other words, it's possible to screw yourself if you install a CPU fan backwards.

Uhm, fans don't actually cool anything.

Fans actually add heat, its the "wind chill factor" that does the actual cooling. Admittedly the heat a fan adds is microscopic when you're talking the temperatures found in a PC.

[FrizzleFried]

I've never seen a pc or other electronic device that blows air in, they all exhaust. But people over build their mame cabs all the time

Dunno what PC's you're looking at but just about every PC I've ever built (as I don't buy pre-boxed crap) has one or more spots up at the front bottom of the case to put a fan or two to suck air in and blow over the hard drives...

[FrizzleFried]

The reason they exhaust is because the point of the fans is to remove heat, not intake air. The pc doesnt need air to function. If you blew air in and just let it leak out, you run the risk of heat building up as all you are doing is recirculating hot air around the case.  The heat sinks radiate heat away from the circuits, warming the air around them the fans blow this hot air out. If you had fans blowing in, you would be blowing this hot air right back on the circuits until it found a way to escape  

Sorry Don... but you are wrong.

BTW - How many PC's have you built?  I'm up to about 80 or so.

[gabe]

Interesting.  I'm a thermal analyst for a multi-billion dollar international company.  This is what I do.  I guess what I do is funny?

NSFW

The Goodfellas - Funny how??

This may be the only worthwhile post in this entire thread.  I LOL'd.

[alfonzotan]

Some fans blow some suck.  The fans at the back of your system (PSU and system fans) are typically designed as exhaust fans.  They suck air OUT of the case out into the room.  Fans on the front of a case (hard drive coolers for instance) are typically going to blow air past the HDD  INTO the case.  As far as heat transfer goes. both methods work equally.  This is convection and the primary drivers in that form of heat transfer are flow speed and delta temperature.  The equation is:

q=h*A*dT

where,
h = film coefficient (driven by flow speed, geometry, etc)
A = surface area
dT = difference in temperature between air and surface temperatures

The direction of the flow makes little difference (it's factored in with h, but a forced convection flow is really independent of what direction the flow moves).  The area is pretty important, obviously, but it's set by the hardware in the system.  The delta temperature is also critical as you get no heat transfer if the air inside the case is the same as the component being cooled.  Increasing the velocity is good, but can make for more noise which is potentially bad.

Anyway, my point is that whether the fan blows air in or sucks air out, it really doesn't make as much difference as you would think.  Now, if I were designing the flow, I'd use exhaust fans or else add fans pointing at components to make sure there was forced flow in those areas.

That'll be $50,000.  Who should I send the bill to?   

These aren't the fans we're looking for.  Move along...

[Vigo]

The reason they exhaust is because the point of the fans is to remove heat, not intake air. The pc doesnt need air to function. If you blew air in and just let it leak out, you run the risk of heat building up as all you are doing is recirculating hot air around the case.  The heat sinks radiate heat away from the circuits, warming the air around them the fans blow this hot air out. If you had fans blowing in, you would be blowing this hot air right back on the circuits until it found a way to escape  

Sorry Don... but you are wrong.

BTW - How many PC's have you built?  I'm up to about 80 or so.

Fans that blow in are generally more of a complimentary fan to increase circulation. Blowing out is generally much more efficient because it anything that blocks the path of an inward flowing fan decreases it's efficiency. A stray ribbon cable or awkward riser card can destroy the air flow of a computer with only inward fans. Fans blowing out pull more evenly from the entire space inside the computer.

[Donkbaca]

Haha... Ive built my share of pcs. Just because youve done things over and over doesnt mean you are doin it right. I guess we are all just smarter than those people with the fancy degrees that manufacture and sell these things to the public.

[bkenobi]

Not to be nitpicky, but don't all fans suck and blow at the same time? I get that some fans are designed to blow, and some were born to suck, but to get things flowing, a fan has to always suck from one end and blow on the other end. It's just kinda basic physics.

Point of reference.  If you are talking about a fan sitting out in the open where the domain is both sides, then yes a fan both sucks and blows.  However, if your analysis domain has the fan mounted on the boundary, then the fan would either suck or blow.  In reality though, the difference is moot as the analysis doesn't care what you call it, it just cares what the sign on the velocity is (which direction the velocity vector points).

 

[ark_ader]

Any horror stories about not properly ventilating a CPU?



This makes my laugh every time.

[ark_ader]

Any horror stories about not ventilating a video card?



 

[SavannahLion]

Haha... Ive built my share of pcs. Just because youve done things over and over doesnt mean you are doin it right. I guess we are all just smarter than those people with the fancy degrees that manufacture and sell these things to the public.

Those guys are under different pressures than we are. The first constraint is cost which is considered almost foremost into their design decisions. IIRC, the target temp for ATX boxes 40C an increase from earlier specs of 38C. A change attributed to higher thermal tolerances of PC components but I think it's just as likely cost is a major factor in that design change.

My point is, engineers don't make design decisions, Bean Counters do. Take a look at the cheap ---smurfy--- Chinese caps that flooded the market. Do you think any honest EE would spec them in a design if cost wasn't the primary consideration? Take a look at the ---steaming pile of meadow muffin--- eye-candy fans flooding the market with their absurdly low CFM ratings, assuming they're rated at all.

Besides if any of you are worth your salt, you'll apply the appropriate technique anyways, or experiment with both and analyze the outcome.

[Donkbaca]

Benkenobi. Can you please explain how not including a 3 dollar intake fan blows the profitability on my 1500 gaming rig?  Damn bean counters!