How Hot is Too Hot For Components

[Brian_74]

I took one of those indoor/outdoor thermometers and put it inside my home theater credenza to measure the temperature. The cabinet where my Sunfire and AVR were measured about 120 degrees F after some time of operation. I've been looking into some way to cool the cabinet using silent PC fans and such. Should I be concerned with 120 degrees? This was with the thermometer setting on top of the AVR which due to large power supply (Harmon Kardon) puts out a ton of heat even though I'm not driving any speakers with it.

Do dedicated pre/pro put out less heat since they don't have internal amplifiers and massive power supplies? Any suggestions would be appreciated!

 

[eknuds01]

I might be concerned. 120 degrees sounds rather warm to me, and that's sort of surprising since you aren't running any tube equipment, nor is your SS gear biased toward class A operation.

However, it doesn't take much to get that hot when your stuff is buried in a wood cabinent. You aren't getting any convection transfer to carry away the heat (hence your desire to add a small fan). A friend of mine puchased a house and the previous owner left the A/V gear behind (included in the price of the home). This guy had the A/V receiver, cable box, etc in a closet and that Marantz receiver did get warm in there (no A/C vent or anything). However, he did a small fan to cool things down. So that did help.

It's my understanding that Sunfire gear runs ice cold. I have a sunfire amp, and it never gets warm to the touch. So is your HK pre-amp the heat source?

If you have an old fan in the house, try placing it behind the unit and see if that makes a difference. You might have to pull the credenza out from the wall to do this. If you have a small desk fan, you can just place it on the floor or stack some phone books to the desired elevation.

There's only so much you can do. The primary sources of heat transfer are: radiation, conduction, and convection. You probably don't want to add a large finned heat sink to lower the temperature. So a fan (convection) is the way to go.

The best solution is to place your components on a rack where you'd have enough air to get in there (or...buy a cooler pre/processor)

 

[Brian_74]

Thanks!

Yeah the Sunfire runs cool. I'm pretty sure the HK is generating all the heat. The thing is a beast.

I was also thinking of something crazy like using a AC powered laptop chiller.

Do dedicated SS pre/pro run pretty cool? Similar heat output to a Sunfire or the like?

 

[Cherian]

120F is very hot. You may want to get it down to about 90F to 100F. Good luck.

 

[eknuds01]

Thanks!

Yeah the Sunfire runs cool. I'm pretty sure the HK is generating all the heat. The thing is a beast.

I was also thinking of something crazy like using a AC powered laptop chiller.

Do dedicated SS pre/pro run pretty cool? Similar heat output to a Sunfire or the like?

I would think so. Perhaps if some of the other guys with SS pre-amps could chime in?

I used my old Yamaha A/V receiver as my dedicated pre-amp for a few months before selling, and it never got hot.

 

[jtwrace]

I would think so. Perhaps if some of the other guys with SS pre-amps could chime in?

I used my old Yamaha A/V receiver as my dedicated pre-amp for a few months before selling, and it never got hot.

My SS pre has been warm to the touch that's it though. My Class A 200w mono blocks on the other hand are designed to run at 125*F. So, yes they are warm....

 

[Cherian]

Count on your power components IE power FETs / transformers running 50 to 80 degrees above the ambient temperature. It is good to keep the ambient temperature as low as you can. 120 degree ambient temperature can mean 160 to 200 degrees on the power components itself. This can lead to premature failure of the components.

 

[Diamonds]

My old Pass Labs X600.5s heated an entire room to over 90 degrees. You coulld not touch them with out having to pull your hand off them after a few seconds.

 

[Dreamer]

Yeah, a Sunfire amp should run somewhere between 88-92 degrees, like most Carver amps.

Now if you were running a Class A amp (Krell, Plimius, etc) you can practically cook a grilled cheese sandwich on those things fins...

I'd seriously consider drilling some vents in you rcabinet, or installing some sort of muffin fan system. You need to get the air moving in there.

There are two approaches to keeping amps cool--moving air in an enclosed space, or out in the open. Since your amps are in a cabinet, you're stuck with rigging some sort of air-moving setup.

Good luck!
--Richard

 

[amey01]

Are you measuring the ambient temperature or the temp of the heatsink?

Try to measure the ambient temperature (I know this is hard), then compare it to the maximum operating temperature of your components.

I know most components specify a maximum operating temperature of about 35C - 40C so 120F is well above that - you should probably look at bringing it down.

 

[Brian_74]

Are you measuring the ambient temperature or the temp of the heatsink?

Try to measure the ambient temperature (I know this is hard), then compare it to the maximum operating temperature of your components.

I know most components specify a maximum operating temperature of about 35C - 40C so 120F is well above that - you should probably look at bringing it down.

I had the thermometer sitting on top of the AVR case, not on a heat sink technically, but I guess the whole metal case acts as a heat sink of sorts. The thermometer has a wire with a temp sensor on the end (for use outdoors) so I will try to dangle that in free air and measure the air temp. Then I can compare the "indoor" reading versus the "outdoor" reading.

Thanks for all the great advice! I'll probably work up a nice fan cooling system in any event.