I am thinking of adding a computer fan to my amp board

[skrip345]

Good morning gentlemen. I toasted an amp last weekend, and fortunately the good guys at POLK audio are sending me another amp to replace the one I cooked. I dodged a bullet there, and am grateful they have agreed to help me out, despite my unit being outside of warranty. This got me re thinking my mounting, and I want to do something different with the new unit so that I don't have more issues in the future. We run at high levels for long periods of time, so the amp gets a work out. What I am considering is a computer fan of some sort, mounted to a board or piece of lexan behind the amp. Naturally I would space the amp and fan off the mount board, so air could flow around and hopefully keep heat build up down. Has anyone done this, or seen it done? Additionally, can anyone give me some direction on a good fan that will do the trick? I have zero clue what I am looking at on amazon. They are pretty inexpensive, but I want a quality component that I don't ever have to worry about again.

 

[JetPowered]

Any 12 Volt fan would do, but you may want to get a quiet model with fluid ball bearings. Low rpm will keep the sound down but you may need more than one to get the same flow.

 

[brockhals]

I ran 4 fans in my car due to my amps being build in behind plexiglass. Two blowing air across the amps, and two pulling the hot air out.

Where are you going to mount it? If you're just blowing hot air across it there may not me much benefit and you'd be better off getting a more efficient amp that you don't need to turn up as high.

 

[Addicted]

I have one of these installed at one end of my amp board.
http://www.sonicelectronix.com/item_16879_Stinger-SGJ78.html
The trigger wire from my head unit controls a auto style relay that then powers the turn on for my 3 amps, and runs this fan. I have all 3 amps mounted a 1/2" off of the board to allow air to travel under them. In three years I have not had any issues, and I to tend to run for long periods of time.

 

[betterwhenitswetter]

What kind of Polk amp do you have? model number please. If it is heat sounds like time for an upgrade, adding fan is adding another power consumer should just buy a better amp.

Are you positive its not moisture/water in your amp?
Where is your amp located in your boat?

I would recommend JL HD amps. no fans needed they run cool given the environment they are in under the helm area which is very hot I have never shut down a HD amp due to heat. in fact JL clams you cant

 

[skrip345]

My amp is mounted in the port locker near the back of the head unit. Its just dead air in there, no ventilation, so I hoped moving a little air would help. I like the look of the stinger. Do you have a pic of your setup Addicted?

 

[skrip345]

The amp is a Pa D5000.5

 

[betterwhenitswetter]

The reason I ask is because I have seen water drip from the windshield screws that attach the windshield to the fiberglass, I have seen where it drips on the wiring harness, water can make its way down to the amp esp... when the boat is underway.

 

[Addicted]

My amp is mounted in the port locker near the back of the head unit. Its just dead air in there, no ventilation, so I hoped moving a little air would help. I like the look of the stinger. Do you have a pic of your setup Addicted?

I can snap a pic this evening.

 

[David Analog]

You only need one 2" fan mounted dead center of the amplifier on a shroud that is equal in size and shape to the heatsink and 0.5" above the heatsink side surface. A correctly designed shroud will multiply the fan effectiveness many times.
Mounting multiple push/pull fans , using free-air fans without a shroud, or using a fan underneath the amp chassis are wasteful, although they may still help.
A fan can provide some assistance. However, at the core of the issue is that you are saturating the amplifier heatsink beyond what it can successfully dissipate and maybe running the individual components (transistors, etc) beyond the level they can dissipate. So if a fan is a band-aid to help on those especially hot July/Aug afternoons, and no more, then it may be enough. But if you are running the amplifier too close to full power continuously, running the minimum stable impedance among all channels, or allowing the boat voltage to dip below 11.8 volts minimum, then the fan likely will not be enough.
In the deep south, it may be a good idea to also add a vent and fan to the compartment so you are circulating some fresh 100 degree air rather than 150 degree air.
The Polk amplifier and the many other imports that share that same platform are certainly a good power per dollar value. But they are entry level and built to meet an entry level price point. So don't expect too much at that price.

 

[skrip345]

I guess I need to take a closer look at what I am running and see how close to full power I am. All I am running is the 4 stock db651's and a 10" polk subwoofer. Ill do some more reading before I install the new amp. Thanks guys.

 

[__ScottyDont]

I added one to my dad's boat where we had the amp mounted in a cabinet. Put a relay in off the amp trigger on the head unit and then pulled power from the 12v system. Worked really well.

 

[smthng]

These are the bomb...
http://amzn.to/1Oib0CJ

$10, so cheap enough to replace regularly if the environment gets to it. They're not whisper quiet, but they move an incredible amount of air compared to regular fans. 12 volts, so wire it to a switch ro relay and you're pretty much done. If it were me, I'd use one as a suck to pull air through the heat sinks, then use another on the door (or via a duct to somewhere else) to exhaust the whole area. Put them both on a relay, activated by the same remote trigger as the amp and call it done.

 

[skrip345]

I do plan to vent the compartment better. I may just put some louvered covers over holes in the port locker door. When all the cushions are installed and the door is shut its pretty stale in there anyways. This winter I will tackle the fans on the amp board. Im planning on adding tower speakers, another amp, another battery, and a fan to keep things moving. More to come with that later... Thanks for the input guys. This forum rocks.