Additional Considerations for Cabinet Cooling & Venting
Cabinet cooling and venting involves several challenges but improving the natural airflow in a cabinet and also adding products to improve booth the natural and assisted airflow can fairly easily solve most problems. The first and perhaps most important step in cooling cabinets is to position components properly by not stacking heat producing components on top of each other, spacing shelving properly (so components can 'breathe'), keeping wiring organized so it does not block airflow, and then have sufficient openings in shelving to allow airflow between the shelves. The best method is to notch out the back of the shelves which provides for easy wiring management as well as good airflow.
Once the natural airflow is maximized, heat will more easily circulate and rise and this is when adding cooling products to vent the upper area of the cabinet will be very effective. More than one unit may be desired if there are multiple shelf areas with heat producing components on the shelves. This way you can vent the individual shelf areas without adding heat to the upper areas.
Avoid Common Misconceptions Related to Cabinet Venting. At this point we are tired at looking at other's claims and especially claims made by so-called cooling professionals with few to no credentials.
1) CFMs and Airflow Requirements. To vent and thus cool cabinets, a huge amount of CFMs (cubic feet per minute of airflow) is not required. Some people try to quantify the CFMs that are needed to cool a cabinet but there are huge holes in the logic and methodology which then negates any legitimacy to these approaches. Plain and simple, there are too many variables which includes the types of cabinets, the equipment involved including specific models, existing airflow...
The bottom line is that if you use some common sense, follow the principles mentioned above which a large portion does not involve spending a penny on cooling products, and then also monitor your systems and the heat being generated, cooling cabinets is not a huge challenge. Another reality, and this is related to the CFM calculation issue, is that you must also consider how many cubic feet of airspace exists in cabinetry once equipment is installed. In many cases it may only be 3, 5, or 10 cubic feet but that would be an exception, of airspace so to put it in perspective, if you have a fan unit that moves 10 cfm in a 10 cubic foot cabinet, you are fully circulating the air in that cabinet once every minute. For most any application that would be sufficient if the above guidelines are followed and in particular, ensuring that air moves freely in the cabinet and around components.
In some cases, cooling cabinets is not that straightforward but it does not have to be overly complicated as well. The bottom line is that components were made to cool themselves and the problem arises when we block the normal airflow so by keeping that in mind and taking basic precautions, you can easily keep your components running cool.
2) How Air Flows and Pretty Diagrams. This is a subject that is sometimes baffling. It is almost amusing to see drawings and diagrams of air moving nicely through a cabinet with cool air, represented with blue arrows, coming in the bottom of the cabinet and then hot air, depicted by red arrows of course, exhausting out the top.....
The fact is that it would be great if it was that easy and air was that 'manageable' but it is not. In residential cabinets, air is going to enter and exit through the paths of least resistance. This includes through cracks in doors, holes cut out for wiring..... A lot of air can enter a cabinet through a small gap in a door and even greater amounts through wiring holes and other openings.
Where the common misconception comes into play is when the diagrams are trying to convince you to pull air into the cabinet from down low and then exhaust it high. Our point is that by doing this, in the real world you will not get that nice even flow pattern. In fact, 9 times out of 10 we would recommend that if you want or need to use two fan units, set both to exhaust air as that is the only way you can be certain that cooler air is entering the cabinet and hot air is exhausting. Unless the cabinet has for some reason been sealed to be air tight, air will find it's way into the cabinet so pulling air out through a fan simply ensures that air is flowing through the cabinet in a more predictable manner.
3) Equipment's Life is Cut in Half with Every 10 Degree Rise.... This is just BS is the only way to put it. We have not seen one single 'valid' study that substantiates this. This is another area where folks have tried to quantify a principle but true research is limited or non-existent. We're not even going to go into all of the variables that would bust this line of reasoning wide open.
The fact is that yes, heat can damage equipment, but the fact also exists that the internal temperatures, the 'normal' operating temperatures in a component, are far greater than we address in cooling cabinets and the equipment in general. Most components today also have thermal protections built-in so if you have a component shutting down due to heat, you should pay attention to the issue. You should also pay attention to ambient temperatures in a cabinet because the problem occurs because several components that generate heat or put in one area and then airflow limited or cut off totally. The point is to not let this scare tactic work on you! Again, use common sense and take the basic precautions.
4) Professional Products vs. Fans. We are now seeing more and more products hitting the market that are marketed as cabinet cooling products, audio video coolers, component coolers.... The fact is that while the principles may be the same between the 'garage' vs 'professional' products, much more goes into the products than just selling a fan and power supply. The fact is that not all fans are created equal and trust folks with a closet full of 'fans'!
In the residential electronics world we have to consider noise and effectiveness equally. Products have to be quiet and effective with very few exceptions. Actually no exceptions when it comes to the effectiveness. Just like an amplifier produces heat though, a fan produces noise. There is no magical 'quiet' fan out there. So why do we have boxes full of fans? It is because we have tested most fans on the market and honestly, all failed. We ended up having fans specially manufactured to our specifications to balance the noise vs effectiveness issue. We also had contend with bearing issues as most fans are not intended for vertical mounting and then electrical noise can also be created by certain types of fans. Then there are also longevity issues and a few other things we won't bore you with.
So the bottom line is that while you can certainly find a wide variety of 'fans' on the market, ensure that your source for cooling products has done their research on the fan types, selected the proper fans and created products for use in residential technology applications. They should also have experience with home audio video systems as well as experience with thermal dynamics. The products should be well tested, aesthetically pleasing, and be supported by a quality company with a strong commitment to their products and customers.