adding a fan to an enclosed cabinet

I'd put the quietest fan with the highest cfm at the top and draw air from the door opening depending on door lip style,if an overlay door is used then either leave the door open slightly or cut an air intake at the bottom.

Kgproperties, very cool implementation of a ventilation system. Depending on one's situation, the fan could actually be mounted in a basement, if the hose can be run through the wall and/or floor. By placing the cabinet openings at the bottom, sizing them appropriately for the air flow, and mounting the hose at the top of the cabinet, a bottom to top flow pattern should exhaust warmer air and allow an intake of cooler air.

Sounds like many of us have gone through a similar exercise. A few years ago I had a cabinet custom made to house (most of) my equipment. The rear wall of the cabinet is 3" closer to the front than the top and both sides. This allowed me plenty of room for all the cables to be run behind the cabinet and out of sight. Heat however, was still a problem. I first mounted a small fan against the back wall, but it was too noisy even though it was the quietest I could find at the time. I ended up buying a cheap flexable cloths-dryer exhaust hose that I attached to the rear of the cabinet where I made the whole for the fan, and the other end to the fan which sits on the floor behind the cabinet. The result; very quiet operation and a great deal of air movement.
Hope this helps! Ken

Go battery operated. Minimizes any potential interferences, usually quiter and resonable cost.

This is like Deja-vu. I have a cabinet similar to Sonofnorway, purchased the variable dc power supply from Radio Shack like Chadnliz's friend, and use the exact fan pictured in the link by Mijknarf. The only thing I can add is whether you blow in our pull out, you are going to have about 5 times the dust you normally do so clean things with a soft brush attachment on a small vac regularly.

If you're interested, the fan I used is a Papst/EBM 8830N. I got it online from Newark InOne. Certainly not the cheapest, but it was the quietest I could find.

I just added a fan to my rack to keep the shelf above my amps cooler. I researched computer case fans pretty heavily and found this fan . It is so quiet I can't hear it running from one foot away. It runs off of a 12 volt DC power supply which I had laying around the house from old calculators and cell phones. To vary the speed of a DC motor you vary the voltage, I used a 9 volt power supply and it gave me the reduced speed and quietness I needed. It may fit the bill for you.

sononorway, sounds like my situation is similar to yours. It's a piece made by a regular furniture company. The back is thin plywood (or fiberboard)-maybe 3/8" thick. I'll check radio shack and see what they have to offer and pick up a couple. thank you both for the replies.

A friend of mine does the exact same thing you are thinking, I believe he uses a variable power supply from Radio Shak so he can control speed.....and thus noise. Computer fans can be had very cheap.

I did that with my cabinet. I chose a 110 volt fan with the quietest motor I could find. Around 27-28 db as I recall. I mounted it to pull air out of the cabinet, and towards the bottom where my amp is located. It kept the amp as cool as if it was out in the open. Quite successful in that regard. My cabinet, though, is more of a "furniture" grade cabinet that an "audiophile" cabinet. The rear wall is thin plywood and unfortunately acts as a sounding board - and tends to amplify the motor vibration. I even used rubber grommets when I mounted it, so there is no direct contact between the fasteners, the fan, or the plywood. Do you have a relatively inert and solid surface on the back of the cabinet to mount a fan onto?