# Heat Dissipation Cabinet Fans?



## Lazy J

I have read bits and pieces on this forum about installing fans in cabinets to assist with dissipating the heat generated by high-wattage receiver units. Could use some assitance.

What exactly should I be looking for? 12V? 6V? Is it better to have one larger fan that moves more air (CFM) or two smaller ones that run at less db? What db will be inaudible for the most part when watching a movie? What diameter?

And, as I have read that these can ideally be plugged in to a switched plug of the receiver so that they willl be running any time the receiver is turned on, what do I need to do so. In other words, how do I get from 6V or 12V to 120DC? Transformer?

Where is a good place to buy these supplies? NewEgg.com?

Appreciate the help. Thanks!


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## salvasol

I remember reading some post about fans from this company http://www.coolerguys.com/cabinetcooling.html :yes:.


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## lcaillo

Or here:

http://www.windywilly.com/index.html


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## trekguy

Do not use a 120v fan—most are too loud.
Use DC low voltage fans designed for a computer; they come in several sizes and some have speed selectors.
One way to power them is with a power brick connected to a switched outlet on your receiver if it has one.
A power supply with selectable output voltages will let you quiet a fan by dropping the supply voltage.
Connecting two fans in series drops the speed and noise of the fans.
Larger diameter fans are often quieter than smaller diameter fans, because the small fans turn faster.
Manufacturer's noise ratings are dubious.
Cheaper fans usually have sleeve bearings.
Better fans have two ball bearings.
Do not use a sleeve bearing fan unless the fan housing is to be mounted vertically.


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## Lazy J

Thanks Trekguy! Great info.

Do you have any supplier recommendations? I cannot get the two above websites to respond to my emails or phone calls.

Thanks again!


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## trekguy

Lazy J said:


> Thanks Trekguy! Great info.
> 
> Do you have any supplier recommendations? I cannot get the two above websites to respond to my emails or phone calls.
> 
> Thanks again!


Sorry no. I've either reused fans from old equipment or bought them at the local Fry's (neither the best selection nor the best price). You will find almost too much information on various forums. Look carefully at buyer reviews. 

Some users report good luck with fan units sold to cool laptops. These usually plug into a USB port.

Some other thoughts. If you are mounting the fans to a back panel it may act as a sounding board and increase the noise level. My fans are mounted in 3/4 material, but the thiner cabinet back still resonated. I found some silicon fan mount/gaskets that helped quiet mine.

Fan noise ratings--my guess is that they measure a suspended fan in sound controlled environment. No fan that I measured came close to the rated noise level. That said if you start with a rating of about 20dB or less, and run it at less than the rated voltage you should be OK. The motors in these fans are very tolerant of undervoltage and will start and run at half or less than the rated voltage. 

If you buy fans and a have an old 6 to 12 volt DC power brick on hand you can easily connect them. RS sells adaptors or you can cut the and splice the wires. Don't worry about polarity. If you get it wrong the fan doesn't turn. Reverse the wires and try again.


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## fredk

Check out this article and the listed fans. One of the fans mentioned is also sold under the Yate Loon name at a lower cost.

In general, the larger the fan, the lower speed it needs to run at to move a given volume of air and the quieter it will be.


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## HokieJoe

Here's my personal (not original) recipe:

http://www.radioshack.com/product/index.jsp?productId=2552560



+


http://www.radioshack.com/product/index.jsp?productId=2552560&tab=accessories


+


120mm PC Case fan(s) from Antec, etc...


+

Extension cord 


In order to use this setup, I bought two AC adapters and adapter "hobby" plugs (male & female). I soldered the appropriate adapters (IIRC, male) to the fan wires. It may not be of paramount importance, but I made sure that I soldered the hobby plugs to the fan wires in the proper order to maintain the airflow direction indicated on the fan. 










Pay no mind to the electrical tape. There's real solder and heatshrink underneath. 

I then plugged the fans in to test them with various voltages supplied by the AC adapter. Satisfied with that, I plugged the AC adapter into an extension cord and the extension cord into a switched outlet on the back of my receiver. Presto, I turn on the receiver and I have airflow. I think I run my fans at around 4.5 or 6 volts. 

Incidentally, the mounting method you see in the first picture was scrapped. I used 30-40 mil PVC shower basin mat stretched across the back of a plywood frame. I then cut out holes for the fans. I mounted it to the back of my cabinet and experienced considerable resonance. I think the PVC mat was acting like a drum head. After discussing my issue with the smart cats over at silentpcreview.com, I settled upon trying low density foam as a surround for the fans. It's the same stuff used to insulate around window A/C units, and can be found at any Home Repo or Lowes. 

, it's easier to show some more pictures than try to explain it, so here goes:



















The foam surround really worked wonders for fan noise. With my prior setup, the fans (or the resonance they created) was very prominent even at 3.5 volts (at which point the fans were pulling too little air). With this setup, my fans run at a higher velocity, yet they're inaudible when my projector, 360 or PS3 are running.


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## hdlvr

I just mounted this unit (side exhaust) on top of the receiver and used a power strip to turn it on/off. Not elegant, but it works great! Receiver was almost too hot to touch due to 2" air space above it; now nice and cool.

http://www.buyextras.com/evavcoblfanf.html


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## Brian_74

Jon,
Here's exactly what I use in my cabinet. 

http://www.coolerguys.com/840556026983.html Let's you connect up to 6 fans. Enough for any job!

http://www.coolerguys.com/840556029977.html Gives you 12V DC power and a convenient plug that works perfectly with above power port

http://www.coolerguys.com/840556000013.html 3 pin extension cable, get whatever length you need to reach the power port from your fans.

Lastly
http://www.coolerguys.com/enmara.html or whatever favorite PC fan you like. Make sure it has a 3 pin cable or necessary 4 pin to 3 pin adapter. I run 2 of these and you can barely hear the fans if they are running and the volume is all the way down...

Use bigger fans if you like. The parts above will give you the basic infrastructure to run just about anything. Plug the power supply into your switched outlet on your receiver to have them turn on whenever your power the receiver.


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## Guest

How did you find the fans? Did you find they were powerful enough to dissipate the heat?


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## Brian_74

ravman said:


> How did you find the fans? Did you find they were powerful enough to dissipate the heat?


I just picked a couple PC fans that looked quality and were supposed to be quiet. I mounted two of them in the back of the section of my AV cabinet where I have my AV receiver. I mounted the two fans so that one blows out and the other blows in. This way you circulate cool air in and blow warm air out, or at least that was the idea. It works pretty well, but depending on how much room you have in your cabinet and your equipment, you may generate and trap more heat and need more/bigger fans. My approach was to start with 80mm fans and if those didn't provide enough circulation, I could easily make the holes larger and install 120mm fans.

Here's a picture


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## Guest

PC fans? How did you power the fans? Or are they AC fans?


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## Brian_74

Read Post #10 of this thread. I laid out everything you need. And yes they are PC fans run using a AC to DC converter. Hope that helps!


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## Guest

Currently I am using AC fans on my cabinet. They are wired directly to the power, by way of power cables that I altered, so they could connect to the fans. One fan is in the bottom left hand corner blowing air in. The second fan is in the top left hand corner, venting hot air out. Both fans work great, but they are so noisy. The cabinet backing seems to act like a sound amplifier. I've tried using foam to insulate the sound and all other methods, but the noise is still there.

I am looking for a more quiet option. Reading various forums, people recommend using PC fans (DC) and opposed to AC fans. They don't make so much noise.

I might look into your solution. I definitely need more quieter fans!!





Brian_74 said:


> Read Post #10 of this thread. I laid out everything you need. And yes they are PC fans run using a AC to DC converter. Hope that helps!


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## Lazy J

Well, since I started this topic I thought I better report back to what I decided on and how it is working.

Being located in the Pacific Northwest where Cooler Guys is located I decided to go with them (see website link in earlier post). I must say, I initially had some trouble getting them to return my calls, but once I did they were extremely helpful and good to work with.

I wound up getting the following:

Two of these fluid bearing fans (http://www.coolerguys.com/sff21.html), one 800 CFM for on top of my Onkyo TX-SR876 receiver to pull the heat out of the component, and one 1200 CFM mounted in the rear panel directly behind and above the receiver to pull the heat out of the cabinet.

One of these mounting kits for the rear panel fan (http://www.coolerguys.com/840556082484.html).

And of course one of these to plug in to the back of my receiver (http://www.coolerguys.com/840556087977.html). The fans come on when the receiver is on.

All I can say is either my receiver is not working properly, or this set-up rocks. I kept reading that the Onkyo receivers were great but they get very hot. So far, mine is running cool as a cucumber, both with the cabinet door open and closed.

These fans can connect in series to suit your needs. In addition, Cooler Guys will soon be receiving ambient lighting for behind a large panel TV (for increased viewing quality) that can also be connected in series with these fans, or of course separately.

Along those lines, for those that prefer to have their cabinets closed, Cooler Guys referred me to this unit that supposedly works great for converting an RF remote ([ame]http://www.amazon.com/gp/product/B000C1Z0HA/ref=olp_product_details?ie=UTF8&me=&seller=[/ame]). Hope this is helpful!


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## Guest

I managed to come to a more quieter solution to my issue also.

I ended up buying 4 * 92mm Antec Tricool fans from eBay.

They have a switch which allows you to set the fan on 3 speeds. On the slowest speed, you can barely hear the fans, on the highest speed, you get a low hum. I also used those rubber gaskets when attaching the fans to my cabinet. I placed two (blowing out) in the top left & right corners, and two (blowing in) in the bottom left and right hand corners.

To power them, I used an old PC power supply that I had lying around. It came one of those compact PCs, so it's nice and small.

I have a Moxi DVR box and it runs red hot all the time. Doesn't matter how many fans you aim at it, it still runs hot. I've read various reviews online that the Moxi boxes are like this and have extremely poor air circulation. Oh well such is life.

I also placed one of the old AC fans I had on top of my Pioneer receiver and have it plugged into the switch there. So when I turn the receiver on, the fan turns on and sucks air out of the unit.

Will monitor it and see how it all goes in the next few days.


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## trekguy

Lazy J said:


> Two of these fluid bearing fans (http://www.coolerguys.com/sff21.html), one 800 CFM for on top of my Onkyo TX-SR876 receiver to pull the heat out of the component, and one 1200 CFM mounted in the rear panel directly behind and above the receiver to pull the heat out of the cabinet.
> 
> One of these mounting kits for the rear panel fan (http://www.coolerguys.com/840556082484.html).
> 
> And of course one of these to plug in to the back of my receiver (http://www.coolerguys.com/840556087977.html). The fans come on when the receiver is on.
> 
> All I can say is either my receiver is not working properly, or this set-up rocks. I kept reading that the Onkyo receivers were great but they get very hot. So far, mine is running cool as a cucumber, both with the cabinet door open and closed.



What internal temp is your 876 showing after a couple of hours of continuous use? 

My 906 and two players and a DVR are in a fully enclosed fan cooled cabinet (passive air intake on the bottom and two 80mm exhuast fans running at ~7 volts). At ~69F room temp the 906 reaches 50 to 53C

To pull up the temp data, with the 876 powered up--


open the cover to access the hidden control buttons.

press and hold the _display_ button and after a moment press the _standby _(power) button

release both buttons and then press and release the _tone_ button


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## Lazy J

trekguy,

I was not aware of this feature. Pretty nifty. I will check it out and report back

Also, as follow-up to my post above, for those interested in ambient lighting, this is what I was referring to:

Here is the new light strip we received: http://www.coolerguys.com/840556088707.html

Works with our ac/dc 12 volt adapters, and we also have a new inline switch available: http://www.coolerguys.com/840556088547.html


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## Lazy J

trekguy (or others interested),

With the above-referenced set-up and fans, and a room temperature around 68-69 degrees, my Onkyo 876 receiver gives me the following readings:

Open - 34/30 Fan

Closed (after many hours) - Readings up to 39/38 Fan

Assuming these are celcius numbers, this equates to an internal temp of 86-93 open and 100-102 closed. Not sure if this is normal or above or below normal, but all I can say is the unit is only mildly warm to the touch, not "on fire" as many forum posts have intimated.


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## trekguy

Thanks Lazy J

I've made some changes to the equipment stack and to the fans in my (nearly) totally enclosed cabinet. 

The Antec Tri-cool fan mounted near the top rear as an exhaust fan is replaced by a larger 120mm Silenx Ixtrema Pro Series fan.

The Antec and two 80mm Silenx fans using the Silenx silicone mounts as standoffs are lying on the rear portion of the 906 top vents. All fans are driven at 9 volts.

With the room at 21C (70F) the 906 shows a peak temperature of 44/45 (112/113F) after three hours.

The exhaust air from the fans on the 906 is partially blocked by the HDDVD player above. I am going to fabricate a shroud to let me position the fans farther back and still pull air from the top vents.

To see a fan setup that is over the top check post 1046 in the 876 thread on AVS.


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## thetheaterguys

We frequently use Raxxess Quiet fans. They are 110 and move 50cfm and are quieter than 30db. We have installed hundreds of these fans in all sorts of situations and I have never had one fail or get noisy after time. They retail for about $80. If you need a thermostat the Cool Components Hi Voltage thermostat works great. It is about $60.


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## Trizzly

Brian,

I digg your solution. I have been researching this for a few days, and found yours description very helpful.


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## Strype

We use a lot of products for our clients from here:

http://www.coolcomponents.com/

very quiet variable speed fans with many types of mounting styles.


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