Fans in semi-enclosed AV unit?

[olds1959special]

I'm looking for advice on my fan setup in my semi-enclosed AV unit. Is there any reason to worry that I'm blowing too much air onto/into the amps since the fans are in the back of the cabinet blowing out? Thanks.

 

[somebodyelse]

There's no need to worry about too much airflow. By semi-enclosed do you mean that it stays as shown, or is there some cover or door that obscures them most of the time?

 

[olds1959special]

There's no need to worry about too much airflow. By semi-enclosed do you mean that it stays as shown, or is there some cover or door that obscures them most of the time?

As shown, no cover or door. It’s closed in the back and open in the front. The fans are noisy though, so I'm wondering if I only need to turn them on if the temperature inside the cabinet gets to over 85 degrees? Or will having them run all the time be beneficial to my gear?

 

[somebodyelse]

There's probably enough clearance that you don't really need the fans at all. More than enough isn't a problem, except perhaps for it being noisy enough to hear. If it were enclosed then it might need some more cool airflow.

 

[Soniclife]

As shown, no cover or door. It’s closed in the back and open in the front. The fans are noisy though, so I'm wondering if I only need to turn them on if the temperature inside the cabinet gets to over 85 degrees? Or will having them run all the time be beneficial to my gear?

You could consider something like this to control the fans.

CONTROLLER 2, Intelligent Thermal Fan Controller Single Zone

Your source to create smart growing systems with components including advance grow tents, inline fans, clip-on fans, LED grow lights, and UIS™ controllers.

acinfinity.com

 

[olds1959special]

CONTROLLER 2, Intelligent Thermal Fan Controller Single Zone

Your source to create smart growing systems with components including advance grow tents, inline fans, clip-on fans, LED grow lights, and UIS™ controllers.

acinfinity.com

This looks like it could be helpful, but for now I placed a thermometer in the cabinet to check the temperature. So far it's been around 80 most of the time, so I'm thinking maybe I'm worrying too much about this, since it would have to get to 85 to become an issue, I'm thinking? If it does it the hotter weather then I could use the fans, but I imagine before its gets too warm I'd be running my AC anyway, but I could also turn on the fans. Here's another pic showing the overall size of the cabinet.

When I place my hand inside and around the amps after a few hours of operation, there is just a slight buildup of heat.

 

[xanalog]

Air flow -like current flow- prefers to take the path of least resistance. [I did not make that up just now!]

*Your photo appears to show that you have 4 isolated compartments w/4 [?] mono-blocks, and FOUR fans.
*Your Vandersteens [4? 2?] should not be excessively power hungry.

*Have you measured surface-temperature delta; with/without those fans?
*Do you hear any fanS noise during normal listening levels?
*Would you consider either an open-air location or a single enclosed plenum to house and to provide forced air exhaust from the amps?
Don't get mad for posing these points that only you can answer!

 

[olds1959special]

Air flow -like current flow- prefers to take the path of least resistance. [I did not make that up just now!]

*Your photo appears to show that you have 4 isolated compartments w/4 [?] mono-blocks, and FOUR fans.
*Your Vandersteens [4? 2?] should not be excessively power hungry.

*Have you measured surface-temperature delta; with/without those fans?
*Do you hear any fanS noise during normal listening levels?
*Would you consider either an open-air location or a single enclosed plenum to house and to provide forced air exhaust from the amps?
Don't get mad for posing these points that only you can answer!

I have one pair of speakers but they are bi-wired with two pairs of amps. The fans are a bit noisy and I prefer not to use them. I thought of at least drilling two rows of holes in the back panel at the top of each section to help with airflow for the amps. Right now there is only one small hole for wires in each of the two top compartments. How do I measure the surface temperature of the amps?

EDIT: Getting an IR thermometer to test the surface temperature.

 

[Haflermichi]

The output devices and heatsinks are at the front on those amps.
At the other end of the chassis than your fans are pointing...

 

[olds1959special]

The output devices and heatsinks are at the front on those amps.
At the other end of the chassis than your fans are pointing...

I know but the fans didn’t reach that side. I got an IR thermometer to check surface temp so maybe I don’t need them.

 

[olds1959special]

I decided to pull out the fans, center the amps in each space, and will be comparing the temperature when they are turned off with when they are turned on for a few hours with this thermometer I picked up at the hardware store. Its accurate within +/- 3.6 degrees F.

 

[kemmler3D]

If the cabinet is not enclosed convection is probably enough. I had to put fans in an enclosed cabinet for a couple hypex nc500s but there was very little space and the cabinet had doors. What I did was cut holes in the back and install 120mm computer fans. That was enough to take care of all heat buildup.

 

[olds1959special]

when I started at 9am it was 75 degrees F ambient temp and the amps were 75. Then one hour later after having them on, the ambient temp inside the unit went up to 78. Testing the temps of the outer cases, I noticed one was a few degrees hotter than the others (?) at around 90 and the rest were around 85. I tested through the vents and pointing at the insides, I noticed the hotter amp was getting up to 100 or more (up to 120!) in the back part of the amp, while the others were staying around 85-90. One of my amps is definitely running a lot hotter! Maybe I need to have the amp checked out. I also think that amp (the amp itself) might be making a vibrating noise. I noticed the sound before but it’s not that loud so I didn’t think it was an issue.

 

[Haflermichi]

You may want to investigate and perhaps learn how to check bias and see if that's something you're comfortable adjusting on your own. The hotter amp may only need a simple bias adjustment?
I was also thinking you could raise the amps higher than their built in feet to increase convective circulation.

 

[xanalog]

How old are these amps? Do you live in a real-dusty environment?
Could there be some thermal compounds used on the internal op-amps that may have 'caked-up' and that may require attention?
Taking IR temps on the case sez nothing about the PCB components' actual temps.

I'd go with @kemmler3D (post#12) suggestions.

Though, you can find some very quite fans and/or explore the use of heat-sinks; which come in many sizes and types...

For awhile, I was running two FOSI ZD3s as monoblocks and found a large heat-sink slab to put directly under both amps (sans rubber feetsies).
It turned out the ZD3s -that were fully hidden inside the entertainment center- never ran hot enough; with or without the heat-sink plate under them.
Although, the case temps were 7degreesC less! >> Less is good!

 

[olds1959special]

How old are these amps? Do you live in a real-dusty environment?
Could there be some thermal compounds used on the internal op-amps that may have 'caked-up' and that may require attention?
Taking IR temps on the case sez nothing about the PCB components' actual temps.

I'd go with @kemmler3D (post#12) suggestions.

Though, you can find some very quite fans and/or explore the use of heat-sinks; which come in many sizes and types...

For awhile, I was running two FOSI ZD3s as monoblocks and found a large heat-sink slab to put directly under both amps (sans rubber feetsies).
It turned out the ZD3s -that were fully hidden inside the entertainment center- never ran hot enough; with or without the heat-sink plate under them.
Although, the case temps were 7degreesC less! >> Less is good!

I was pointing inside at the components through the top vents. I’m taking the amp to be looked at tomorrow.

 

[xanalog]

I’m taking the amp to be looked at tomorrow.

IMO: It's much more fun taking them apart, yourself...
What's the worse that can possibly happen? Electrocution via cap-discharge!
pffft!

 

[Haflermichi]

External "heat sinks" are not going to do much good unless they are in direct and intimate contact with, and thereby increasing the surface area of, the existing heatsinks.
If they are not in direct contact the amp will just be heating them up after the fact. This would be the same or even less effective than a fan, which at least is increasing air flow.

 

[Sal1950]

The fans are noisy though, so I'm wondering if I only need to turn them on if the temperature inside the cabinet gets to over 85 degrees? Or will having them run all the time be beneficial to my gear?

Try using some good Noctua 5v USB or 12v computer fans to lower noise. The 12V models all come with a inline resistor to lower speed and noise if you find them too noisy without.

 

[Haflermichi]

For clarity...these are "heat sinks"

This is not a heat sink, it's a "fan board".