Airflow & Cooling: The THG Cooling Potential Rating
Many readers have asked why we don't include airflow measurements and sound measurements in our case reviews. We believe that while both of these elements are very important, the outcome can be altered by the use of different fans or fan controls. Based on reader feedback, in most instances we agree with the majority of comments to the effect that "I never use the stock fans that come with a case. Instead I replace the fans with XX brand, because I have found them to work better due to...etc. etc. " We agree! In most instances depending on what we need, we adjust the fans in the case accordingly.
No matter what the requirement - the noise factor, a lit fan, or greater airflow - there is almost certainly a fan that will fit the bill. We focus more on the level of airflow through the case: is the case vented correctly in the front with a good level of ventilation in the back to remove the heat from the case? This is far more important than developing a testing scheme based on manufacturer provided numbers and never doing any real world testing. The bottom line is this: does the test system run sufficiently cool and is it quiet enough for you to tolerate? We have added an option in the table below that rates the overall cooling potential of each case on a rating scale from 1 (Poor) to 10 (Excellent). The majority of cases that we tested for this review rated in the 6 to 8 range, which is quite acceptable in all but the most unique circumstances.
Smoking Out The Airflow
Note that we label this "Cooling Potential Rating." This is because frequently a case will not have all of the fan slots filled from the factory build. In getting the Cooling Potential Rating number that we assigned each case in this review, we fed smoke through each case to trace the path of the smoke through the case. We judged the amount of smoke that was moved through the case and exhausted out the back of the case. We also wondered about our own internal fan system efficiency, that being our lung capacity, as we puffed our way through many cigarettes as part of the test process. In instances where the case offered a side panel window, we were provided the best visual opportunity to see this process. No case in the review totally failed the test, and all of the cases provided adequate airflow. Again, this can be altered by a different choice of fans that may be used inside the case.
Another innovation worth mentioning is the acceptance of new fan bus control units to alter and control the speed of the fans within the case. These units offer adjustment knobs which when connected to the case fans allow the speed of the fans to be controlled from fan bus controller that is normally mounted into the front bay of the computer. While these devices continue to be widely accepted by and used in the case `mod' community, the effectiveness of these units is subject to the performance of the installed fans.
With the boxed and blister packaged products not yet widely available to consumers from sources like Vantec (for example), the fan bus control devices can help you adjust the performance of fans within the case by speeding them up and slowing them down. Still, knowing the temperature limits of the internal devices within the PC, as well as getting accurate temperature readings from within, are required. At least one case that we reviewed offers such a device as part of its overall build strategy.
Fan bus devices should still be used with some caution, as without a good understanding of the temperature limits of your PC, these devices when turned down to quiet the fans may not move enough air through the case. I don't think we need to point out that this can cause overheating problems. What perhaps is more innovative is the new `processor tunnel technology' that uses an adjustable tube to vent the heat from the processor directly out of the case side panel.
With temperatures of the components within your computer continuing to rise due to faster speeds, adequate cooling will continue to be very important. While opinions on cooling and cooling methods differ, it is important to study the means of cooling within your case and to make sure that you have adequate and significant airflow. We estimate that even one fan turned the wrong way within your case can reduce the effective cooling within a case by as much as 50%.