Cooling Fan

[gadgtfreek]

I have a 2 door, 4 shelf ent center that contains my 1909 and bd35 on one side(1909 on bottom) and a TivoHD and Dish 722 on the other side(722 on bottom).

Ive got the BD35 as high as possible, but since I added the shelf over the 1909, there is not a lot of room for air out of the back. Its not getting very hot, but I wonder if I should not run some kind of ventilation.

Here is what I was thinking:

HomeTheaterCooling.com The Professionally Quiet Fan

 

[Paul Wozniak]

Elway, is your unit enclosed in back? Do you have doors on the front? The reason I asked, is if it is enclosed, a fan will just end up recycling the heat in the unit. A friend of mine had this problem, and we ended up removing his glass doors and cutting open the back panel (It was just a stiff cardboard and did nothing for the structural integrity.) This allowed air to move easily through the unit, and we found that a fan was unnecessary.

 

[jayn_j]

$50???? For a muffin fan???!!!

I read the hype, and frankly don't see what makes this so darned special. You can buy an equally quiet fan for 1/3 the price at Frys.

I also agree with Paul. Modern A/V equipment is designed to be stacked without the need for a fan.People who run into heat problems generally mash stuff into cabinets as tight as it will fit. That gives heat no place to go and it simply builds up.

Heat dissapates by one of three ways; convection, conduction and radiation. Of the three, convection is the most efficient. However, convection relies on air flowing freely. Natural convection relies on the principle that warm air rises out of the cabinet from the top edges of the opening and cool air flows in from the bottom.

A fan is a way of increasing the efficiency of convection cooling, by forcing a supply of fresh air. A fan needs a source of cool air and an outlet for the hot air.

Many people just place a fan at the back of a pile of equipment and then wonder why it doesn't help much. The problem is that pressure will follow the path of least resistance. That is generally to bounce off the back of the equipment and then through the back of the rack. The only cooling that happens in that scenario is conduction to the back of the equipment, and then convection off a very small surface.

You need to block off the airflow in the back, except for the duct to let the forced air in. That's what the $150 panel accomplishes from the website you cited. You also need to make sure the front is open so air can get out. If you do that, you will be surprised at how small a fan is actually necessary.

Any fan can be made quiet by doing two things. First, lower the mechanical noise by mounting with rubber washers and /or a foam gasket. Second, you need to do something to smooth the airflow path. A filter n the input side does a good job of this and has the added benefit of eliminating a lot of the dust that collects in the equipment. If you do those three things (mounting, filtering and bulkhead), you can get by with a cheap muffin fan and have a quiet and more efficient cooling system.

 

[gadgtfreek]

I wasnt necessarily going to use that fan, because I do agree its a bit overpriced.

In m"y cabinet there is a 5"x5" hole behind the Denon, facing the back wall. The Denon has about 4" above it to the bottom of the BD35 shelf, and has 2" on each side. The front is a glass door, that cant be removed (WAF).

My thought was a 120v fan for the back hole, to pull air out of the compartment and blow it against the wall, Id assume itd pull air through the front that would be cooler and pull the warm air out. Like I said, the Denon is still much cooler than my Onkyo ever was, so it may n ot even be a big issue.

 

[William1]

I run 2) 6" 120V fans, wires in series (makes them run at half speed for nearly inaudilbe running). They are switched by a combination relay/thermostat controlled by the 12V DC trigger signal from my Rotel. My cabinet never gets hotter than 10 degrees F over ambient. Almost all openings on the back of the cabinet are covered by hinged panels. A bottom opening about 5" by 15" was left open, the fans installed at the top, exhausting the heated air. I spent about $10.00 apeice for the fans and I sent about $20.00 to build the relay thermostat unit.