howto add ventilation to AV cabinet? (1 Viewer)

[Gary Mui]

I've got my equipment in a AV cabinet with a glass door, and no backing. Obviously my equipment (especially my Yamaha HTR-5590 receiver) gets pretty hot in there.

Instead of getting a new AV shelving system with no sides, what can I do to improve ventilation?

I was thinking about adding some 80mm computer fans to the cabinet, either at the back or drilling holes above the receiver. But is there an easy way to power these 12V fans?

Or else, what other options do I have? TIA.

 

[Allen Ross]

you can get some 120MM 120V fans, but they will be about 3 times as much, at least for the ones i have found.

 

[DaveKahler]

I'd either go with A/C fans, or you can get either a power interver or computer power supply and plug it into and aux outlet on your receiver if you have one.

 

[Craig Treusdell]

I have a similar setup except I have backing on my cabinet.

I put my receiver on the top shelf with about 4 inches of clearance. I mounted a 4 inch a/c fan on the back so that it blows air across the top of the receiver. It is plugged into the aux power supply on the back of the receiver that is controlled by the receiver. All I had to do was to solder a 2-prong power cord to the fan leads and covered the connects with heat-shrink.

In my first attempt I cut holes in the backing at the bottom to allow cool air to flow into the cabinet and tried to pull the air out at the top, but the receiver stayed pretty warm.

After I turned the fan around to blow across the top of the receiver it stays very cool.

Before connecting the fan to my receiver, I measured the current durning the turn-on, normal run, and even when I stopped the blades while power was applied, and the current did not change. I'm not sure if all a/c fans have this, but I think the term is "impedance protected". Can someone verify if all a/c fans have this feature or what the term is to describe this? Thanks.

 

[Wayne A. Pflughaupt]

I mounted a 4 inch a/c fan on the back so that it blows air across the top of the receiver.

I really have my doubts that this is the best way to do things. A receiver’s normal cooling is by convection – as air inside it heats up it ventilates out the top, cool air comes in from the bottom. If the rising hot air meets a mass of denser, cool air from an external fan, it seems to me that could prevent the hot air from exiting the vents, and possibly accumulate inside the receiver’s chassis.

In professional audio rack systems, air is exhausted with fans out the top of the rack. If the same system is used in a home system, it will allow a receiver’s normal cooling to function (it’s normal for the top of it to feel warm).

Regards,
Wayne A. Pflughaupt

 

[MikeTC]

I would use 120VAC fans. If you must use 12V DC fans, use a wall wart (120VAC to 12VDC transformer) and pulg it onto your receiver's switchable outlet so it will turn on the fans when the receiver is on.

I agreed with Wayne that it would be best to exhaust hot air than blowing cool air in.

 

[Gary Mui]

Thanks for the suggestions guys.

My only concern with the AC fans is that they're generally pretty big. It would be optimal if I used 80mm computer fans, then cut some 3" diameter holes in the top of the cabinet, and mount a couple of 80mm fans to exhaust the air up and out of the cabinet (from the receiver).

MikeTC: What's a "wall wart"? Do you have a link to what one looks like? I guess I'd have to do some soldering to wire my fans to it?

Also, what precautions should I be aware about when using the Switched AC outlets?

 

[MikeTC]

http://www.radioshack.com/product.as...Fid=273%2D1779

RS called it a AC-DC (Home) adapter. Anyway, I would cut the connector off and connect the wires to the fan. Just be sure you know that the fan will be on when the reciever is turn on.

 

[BenSC]

Wallmart is a store here in the US. Any generic store like Costco, Kmart, etc should work. I'm not sure what you have up there in Canada.

 

[Peter Jessee]

I've added cooling to a couple of cabinets, and my first try with a 120 VAC fan was a bust. The damn thing was almost as loud as a vacuum cleaner - not what you need when you're trying to listen to music! I got some advise from the web, and got a 12 VDC fan and an adjustable power supply that can go from 3 VDC to 12 VDC in 1.5 volt steps. You plug the power supply into the switched aux AC outlet on your receiver/pre-amp, and the fan(s) run when the amp does.

I found that the 12 VDC setting was still too noisy, and ended up switching between 9 and 10.5 volts, depending on the room temperature and how loud I was pushing the system. 9 volts is inaudible, while 10.5 volts provides good cooling with tolerable noise. The switchable power supply is $10-20 at Radio Shack, Fry's or almost any electronics supply store.

 

[Gary Mui]

Oh, WAL-MART. The original post said "wall wart" which threw me off :S Yeah, we have walmarts up here.

Peter Jessee: So did you just snip off the connector on that adjustable powers supply, and soldier on the leads from the fans? And how many fans did you have hooked up to it? Thanks!

 

[Peter Jessee]

Peter Jessee: So did you just snip off the connector on that adjustable powers supply, and soldier on the leads from the fans? And how many fans did you have hooked up to it? Thanks!

I did that for one cabinet. On the other one, I bought an inline socket that matched the power supply plug, so that I could easily disconnect the fan or daisy-chain other devices. You can use this DC power to turn on power amps with nominal 12 VDC trigger inputs. These power supplies usually put out 250-500 mA, which is enough to run 2-3 fans or DC triggers. I'm only running one fan now, but plan to add another when I permenantly add my old Hafler DH220 amp to the system.

 

[Craig Treusdell]

Wayne and Mike --

I understand the physics behind heat and air flow and agree in a sealed environment with one path in and one path out that pulling air out at the top is the ideal solution..

Most of the backing is off at the top so I can access the back of the receiver. This is my guess as to what caused the fan to be ineffective when trying to pull air out.

When blowing air in, it probably causes a suction across the top of the amp, causing the hot air to move to the front center of the cabinet, and wrap around both sides and out the back sides. Or maybe it is just circulating the same air.

Just a guess.

However after playing it hard for a good time only one setup kept the receiver cool -- blowing in.

 

[tom_furman]

I have a little 12v power supply plug into the back of my receiver, and a little 4" computer fan plugged into the power supply.

I have the fan laying flat on the top of my receiver so that it pulls the hot air out of the receiver.

 

[Bryan Michael]

anyone know what a standard operateing temp of a amp should be like what to look for it not to execede. i took mesurements on my adcom and got around 110 with the volune at 60 db and on for 2 hours.

 

[Allen Ross]

it should have a thermal shut down, if it gets to hot it will shut down, but yet again heat is bad in electronics, so try and keep it cool as possible.

 

[BryantF]

I'd either go with A/C fans, or you can get either a power interver or computer power supply and plug it into and aux outlet on your receiver if you have one.

I have a question about using a computer power supply. In a computer, the fans are only powered when the machine is on. So a computer power supply won't work in my AV cabinet unless I convince it that its "imaginary" computer is turned on. I was wondering if anybody knows how to "trick" the power supply into thinking it is connected to a computer which is always on. My guess is that I simply need to splice together a couple of wires, but I don't know which ones. Does anyone know how to do this?

 

[Rory Buszka]

A fan that's silent at 9 volts? Tell the people at SilentPCReview.com about that one! Their most widely-accepted standard for quiet cooling is a Matsushita "Panaflo" (Panasonic) Model L1A 80mm fan running at 5 volts. I have three such fans in my computer's case right now. They are truly inaudible.

 

[Arthur_King]

there's always the commercial route (I know its a DIY forum)

www.activethermal.com

Daffy Arthur King
with the brain of a duck

 

[Cam McFarland]

Whats a "wall mart"....

I thought it was Paris Hilton for a second...LMAO!