Hi there,
I am currently building a full size home arcade machine based around a PC. I am considering water cooling it and being completely fan-less. Given the size of the case (1.8m tall x .6m wide) I have PLENTY of space to fit an external radiator.

I was wondering if I acquired the radiator and fins from the back of an old fridge freezer and plumbed this to waterblocks/heat sinks and pump to the PC motherboard, would the huge surface area of the fridge rad negate the need for fans?

I am hoping that the surface area alone would be sufficient to dissipate the heat out into the room?

The motherboard will be mounted on the inside of the arcade cabinet, rather than sit in a pc case, so the tubes would be routed from the mobo and straight outside to the back of the machine to the rad.

Any thoughts? Would this work or am I barking up the wrong tree here? I want absolutely no fan noise from this thing as it's going to double up as a media server, so will be left on for hours at a time in the corner of my living room.

Thanks for any advice

I have a hunch that that type of radiator is totally insufficient.

It's much better to get hold of a radiator the type used for heating rooms, preferably one roughly covering the back of your setup.
Beware of galvanic corrosion though, and if you get a used radiator it will very likely need a thorough internal cleaning before use.

Cheers
Olle

Really? Whats the heat output? I thought it would be in the region of 100-200w of heat max. The smallest house radiators are 500w. I would have thought a freezer would have to displace more heat than a PC?

you'll have plenty of room there to put a couple of 120mm very slow running fans there, together with lots of sound proofing, so you wouldn't hear anything.

The freezer radiator is a bad idea because you will need a huge pump that will make a lot of noise.

OK, thanks for the feedback.

I am thinking then of buying a radiator from one of the many watercooled PC parts suppliers online and mounting it skywards at the top of the cabinet blowing straight out of the top. My question would be what type of radiator and fan setup should I buy?

I have seen ones with a mount for a single fan, 2 fans and 3 fans. What do I actually need? I want it to be as quiet as possible, so I assume adding more fans makes it more noisy?

I won't be overclocking, or pushing the PC particularly hard, and it won't have the constraints of a small PC case to retain heat but I don't know how to choose what I need.

I guess that the slower the fan(s) the quieter it would be, but that also reduces airflow, so the fins on the radiator would need to have enough space for air to pass through it?

Anyone offer some advice as to the radiator/fans that would work for me?

You must also consider the coolant temperature. House warming is done with water temps >50C, typically 60C. In the computer you want the water temp to stay below 40C. That makes a huge difference in heat output!

Full size (>250 litres) freezer class A draws ~30W average! It only has to dissipate as much as get in through the insulation. And I think the coolant is warmer as well...
A high end gaming PC draws more than ten times that.

Cheers
Olle

Man.... I have soooo much to learn. Trying to make a quiet PC is totally new to me. I come from a world where computing power and functionality is the only concern. Now I need the thing to shut up, I'm completely at a loss.

I appreciate the feedback so far, I really do!, can anyone tell me what size 'off the shelf' radiator and fan setup I should be looking at?

This is a 'gaming' machine, but not in the traditional sense. the GPU will be doing pretty much zip... but the CPU will do all the grunt. so I will be using any old crappy onboard graphics, and the CPU doesn't need to be anything amazing either (think Pacman and Galaxian and you're somewhere close!)

The only other thing it will do is act as a file server, so I plan to stick 6x 1.5tb SATA drives in it, but my idea was to put them in their own vented compartment so as not contribute to the overall heat in the cab. Would a single rad that takes a 120mm fan do the job, or do I need one that takes 2 fans... or 3?

I have built a couple of these machines. Since you have a ton of room inside the machine, don't spend money on intricates and water cooly stuff. Instead add some insulation!

check: popsynth dot com and search for mame.

I went with all Asus boards that have no fans. No wearing parts except the one fan inside the power supply, and the huge one on the CPU. I used one quiet cheap household 110 fan in the stock Arcade vent (near the spiderman sticker above the door in the back of the machine). On a typical arcade shell you have thick heavy particle board all around. Use sheets of blue durafoam (like for stucco jobs) in places where the sound needs dampening. You can make baffles to trap noise. I also sprayed expanding foam in corners and crack areas.

With that little heat output I agree with Popsynth: Go for quiet air cooling!
Cheaper, less maintenance and minimal rate of failures!

Cheers
Olle

watercooling doesnt fail if you know the slightest bit of what you are doing and never go custom self made DIY stuff.

air cooling is just NOT SILENT at all.

5 fans is not silent. Turn off your computer. turn it on. can you hear any difference? I cannot. Water = silent.

5 fans isn't silent.

1 slow fan is. Especially boxed inside a wooden enclosure where there's room for lots of sound proofing.

yeah 1 slow fan definitely is. You also have to count the psu fan if you dont go fanless for that.

I would actually toy with a PICO brick if i was doing an arcade game setup. The speed of the computer I would believe to be minimal. The only thing I would consider is getting the clearest analog out signal on a vid card. Matrox comes to mind there in passive solutions.

i no h2o cooling expert..but if its that big of a case i would want to use a big car style radiator on the top of the case with the mobo down low, so the natural heat flow would help circulate the water, allowing for a quieter pump.

The heat generated from the water blocks rises up to the radiator at the top, as the cool water returns from the radiator it sinks back down the return line to the mobo. - every little bit helps when silence is the goal.

well. thats complicated.

you want the radiator at the same level as the blocks, otherwise you could suck in air or having pumps being strained or water spraying in an odd location. the water level issue can come into play when heights are very different and the pumps are silent vs super strong noisy ones for overclocking crowd.

it aint easy but its really fun

The issue is also for this: what and where is your resevoir? if you have no resevoir and the system is sealed , you can do anything you want and make the radiator on top in a sensible way like you said. Zalman's reserator that I have is peculiar as the resevoir IS the radiator as well. I have to keep things side by side and relatively level.