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Knucklehead
02-18-2009, 12:31 PM
I have 3 brushless fans to install on my H/T cabinet...is it better to pull heat away from the AVR or introduce cool air to the unit. My cabinet has a plexi glass door on the front which i like to keep closed due to the kids curiosity. The cabinet contains all of my equipment. thanks for the input.

CaligulaPolk
02-18-2009, 12:33 PM
I have 3 brushless fans to install on my H/T cabinet...is it better to pull heat away from the AVR or introduce cool air to the unit. My cabinet has a plexi glass door on the front which i like to keep closed due to the kids curiosity. The cabinet contains all of my equipment. thanks for the input.

Damn kids' curiosity! my 15 months old love to touch my electronics so wife decided to buy me sauder rack for v-day. I think you will better off to introduce cool air to the unit. Unless you want extra heat in your house or more hot in your cabinet to keep the lizards warm :D

Knucklehead
02-18-2009, 12:36 PM
Thanks, makes sense, I just hope these things arent too noisy.

CaligulaPolk
02-18-2009, 12:40 PM
Thanks, makes sense, I just hope these things arent too noisy.

i also suggest you place cabinet near Air conditioner outlet, it would help.

i think itd be save money if you tape a tube from ac outlet to your cabinet and let A/C do the work and less noises :D
:p

acsubie
02-18-2009, 12:43 PM
i have a fan on top of my onkyo 805 and it is pulling hot air OUT of the avr

Knucklehead
02-18-2009, 12:43 PM
WOW!!! thats a great idea! Now I know why you guys get paid the big bucks!

leroyjr1
02-18-2009, 12:45 PM
Thanks, makes sense, I just hope these things arent too noisy.


I have a 110volt 4 inch fan on my cabinet for my ps3 and I pull the air out(less dust in cabinet). It's a little too noisy for my taste also.

Knucklehead
02-18-2009, 12:49 PM
I have a 110volt 4 inch fan on my cabinet for my ps3 and I pull the air out(less dust in cabinet). It's a little too noisy for my taste also.

thats what im afraid of...my dang xbox360 sounds like its getting ready to take off as it is since micro-suck fixed it. :rolleyes:

leroyjr1
02-18-2009, 12:57 PM
What size fans are you using, and are they 110v/12v? I'm looking to get some smaller one's. Also what db rating did they have on the box?

Thanks

hearingimpared
02-18-2009, 01:04 PM
As long as there is air moving in either direction it will cool the equipment. However if the cabinet enclosure is closed on three sides with the fans at the back, blowing air in won't be as efficient all pulling the air out.

Knucklehead
02-18-2009, 01:12 PM
110v 4inch it says "impeadance protected" on the box but no db rating.

WilliamM2
02-18-2009, 01:13 PM
If you need quiet fans, these are the quietest I have found:

http://www.newegg.com/Product/Product.aspx?Item=N82E16835186121

I run them off a 6v adapter, which makes them almost silent. I can't hear them at all with the door to the cabinet closed, with it open, I have to be less than a foot away to hear them.

Knucklehead
02-18-2009, 01:21 PM
cool!..no pun intended! thanks for the link.

kneedragger37
02-18-2009, 02:54 PM
Is there any rule of thumb for the CFM of the fan compared to the size of the cabinet?

My cabinet is about 16 cubic feet (2ft x 2ft x 4ft) and has an AVR, XBOX 360, and Wii in it, among other equipment, and I leave the door open when using it because I'm worried about heat building up...

And I saw someone asking about the db rating of the fan -- how low a rating should one look for?

WilliamM2
02-18-2009, 03:23 PM
Is there any rule of thumb for the CFM of the fan compared to the size of the cabinet?

My cabinet is about 16 cubic feet (2ft x 2ft x 4ft) and has an AVR, XBOX 360, and Wii in it, among other equipment, and I leave the door open when using it because I'm worried about heat building up...

And I saw someone asking about the db rating of the fan -- how low a rating should one look for?

I wouldn't worry about cfm, it doesn't take much to cool audio components, and high cfm generally means more noise. As far as db rating, there is no standard way of measuring, quite often a fan with a 19db rating will actually be louder than a fan with a 30db rating.

I build a ton of computers every year, and have tried hundreds of different fans over the years. The ones I linked to above have been the quietest of them all. And as I noted, use a 6v wall wart to make them even quieter. If you have the room for bigger fans, they will push more air at lower RPM's, which will make less noise.

ntculenuff
02-18-2009, 04:13 PM
in car audio to cool amps in an enclosure we would have a fan pulling out hot air and one pushing air in that way you have a flow of air movement

leroyjr1
02-18-2009, 04:47 PM
If you need quiet fans, these are the quietest I have found:

http://www.newegg.com/Product/Product.aspx?Item=N82E16835186121

I run them off a 6v adapter, which makes them almost silent. I can't hear them at all with the door to the cabinet closed, with it open, I have to be less than a foot away to hear them.

Do you have a link for a 6v adapter?

Thanks

BlueFox
02-18-2009, 05:06 PM
For quiet, efficient, cooling operation run a drip irrigation line over the AVR to cool it. Works great.

Seriously, if you find a quiet (inaudible at no music playing) let us know. My amp runs hot by design, and I was concerned last summer since it was getting really hot. I bought this "quiet" fan that I could hear during low passages in the music, so I had to get rid of it. I even moved my refrigerator into the garage to eliminate back ground noise. While I don't care if the amp is hot during the winter, I am concerned about this coming summer, since I now have 2 amps running in mono mode.

WilliamM2
02-18-2009, 05:08 PM
Do you have a link for a 6v adapter?

Thanks

No, I have quite a few adapters around the house, and just used one of those. If I had to buy one, I would go for one of the adjustable 3v-12v models. That way you can adjust the speed to your needs. Radio shack has them, so does Walmart.

comfortablycurt
02-18-2009, 05:24 PM
Personally I'd have them pulling the hot air out of the unit. As others have said, if they're in a tighter area, pulling cool air into the unit isn't going to be as affective.

steveinaz
02-18-2009, 05:51 PM
Agree with "evacuating" hot air versus blowing air on the component. Most components are designed for airflow to come from the sides or bottom, run across the heatsinks, and exit the top. Using a fan to suck the hot air out would be more efficient/effective IMO. Heatsinks are usually thicker at the bottom, and thin out as they get to the top. Blowing air in would force heat back down to the thicker bottom portion of the heatsink---counter-intuative.

WilliamM2
02-18-2009, 06:18 PM
Whether they blow in or draw out really depends on the cabinet. Most cabinets have open areas behind the components, so that you can get to the connections. In that type of cabinet, it won't draw air through the cabinet at all, it will just draw air from directly below the fan, and spit it back out.

On my cabinet, having the fans draw out didn't lower the temps at all. So I have one blowing on the amps, and one blowing on the pre-pro. Everything remains cool to the touch.

If you set the fans on top of the AVR, I would agree that drawing air out would be best, but keep in mind that if it's a closed cabinet, that heat is just staying in the cabinet.

mmadden28
02-18-2009, 06:45 PM
Agree with "evacuating" hot air versus blowing air on the component. Most components are designed for airflow to come from the sides or bottom, run across the heatsinks, and exit the top. Using a fan to suck the hot air out would be more efficient/effective IMO. Heatsinks are usually thicker at the bottom, and thin out as they get to the top. Blowing air in would force heat back down to the thicker bottom portion of the heatsink---counter-intuative.

+1 on hot air evacuation, in addition to other similar comments.

Hot air rises, so its logical to expel the hot air out the top.
While I haven't installed my fans yet (right now they are just placed in the cabinet expelling), my plan is to take cool air in at the bottom, and expel it out the top. I am going to ensure that the CFMs of each are equal. My cabinet is a sealed type, really no vent holes, so I plan to cut holes and mount the fans as well as use an air duct register filter to ensure that I don't intake any dust.
If I were only dealing with one fan (in a more open rack design) I'd use a temp controlled fan that varies its speed based on a temp sensor. This helps ensure that the fan is quietest when it is not relaly needed, but will speed up as it gets too hot. In my case so far I have not heard the fan over the sound of my DVR.

leroyjr1
02-18-2009, 07:07 PM
+1 on hot air evacuation, in addition to other similar comments.

Hot air rises, so its logical to expel the hot air out the top.
While I haven't installed my fans yet (right now they are just placed in the cabinet expelling), my plan is to take cool air in at the bottom, and expel it out the top. I am going to ensure that the CFMs of each are equal. My cabinet is a sealed type, really no vent holes, so I plan to cut holes and mount the fans as well as use an air duct register filter to ensure that I don't intake any dust.
If I were only dealing with one fan (in a more open rack design) I'd use a temp controlled fan that varies its speed based on a temp sensor. This helps ensure that the fan is quietest when it is not relaly needed, but will speed up as it gets too hot. In my case so far I have not heard the fan over the sound of my DVR.




What kind of fans are you running?

noscivic
02-19-2009, 02:54 PM
i have a fan on top of my onkyo 805 and it is pulling hot air OUT of the avr

I am curious about doing the same, but not sure on how to go about supplying power to the fan. Do you have an standard outlet plug connected to fan and the plugged into the power outlet on the back of the reciever, so when the reciever is turned on the fan is turned on, as well? Or is there a better, different way to go about it. Im new at this thing:o

Thanks,
Gary

noscivic
02-19-2009, 02:56 PM
i have a fan on top of my onkyo 805 and it is pulling hot air OUT of the avr

I am curious about doing the same, but not sure how to go about supplying power to the fan. Do you have a standard outlet plug connected to fan and the fan plugged into the power outlet on the back of the reciever? That way the fan is turned on with the reciever? Or is there a better, different way to go about it. Im new at this thing:o

Thanks,
Gary

Ender
02-19-2009, 03:14 PM
Whether they blow in or draw out really depends on the cabinet. Most cabinets have open areas behind the components, so that you can get to the connections. In that type of cabinet, it won't draw air through the cabinet at all, it will just draw air from directly below the fan, and spit it back out.

On my cabinet, having the fans draw out didn't lower the temps at all. So I have one blowing on the amps, and one blowing on the pre-pro. Everything remains cool to the touch.

If you set the fans on top of the AVR, I would agree that drawing air out would be best, but keep in mind that if it's a closed cabinet, that heat is just staying in the cabinet.

QFT. As a person who loves building computers and is obsessed with airflow, I would have to agree that it depends on how your cabinet and receiver was built. It is better to have cool air to flow in due to air's excellent heat conductivity than it is to suck out hot air.

Also, most often, despite dust concerns, it is better to blow air in as it causes natural air pressures to have an outward air flow. So, if you were using one fan and had at least two holes for air flow, you would want one fan to blow in while the air leaks out the other hole. You're basically continuously pouring in clean water into a murky pot and causing the murky water to flood and leave the pot.

avhomedesigns
02-19-2009, 04:35 PM
pull air out

cdn5003
02-19-2009, 06:12 PM
I have this Thermaltake fan on top of my 706 and it does a nice job. It is very quiet and has a speed adjustment knob. I have it running constantly on the lowest possible speed and it stays cool.


http://www.amazon.com/Thermaltake-Mobile-Fan-External-Cooling/dp/B00080G0BK/ref=pd_bbs_1?ie=UTF8&s=electronics&qid=1235081356&sr=8-1

BlueFox
02-19-2009, 08:01 PM
I have this Thermaltake fan on top of my 706 and it does a nice job. It is very quiet and has a speed adjustment knob. I have it running constantly on the lowest possible speed and it stays cool.


http://www.amazon.com/Thermaltake-Mobile-Fan-External-Cooling/dp/B00080G0BK/ref=pd_bbs_1?ie=UTF8&s=electronics&qid=1235081356&sr=8-1


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