To make the cleaning job easier, I use a battery-powered mini vacuum (4 AA). You can buy one at computer shop for RM15-20.
The card shown here is Sapphire Radeon Toxic HD4850 512 MB. Aside from high performance, Radeon HD4800 series is known for it's high heat, too. Zalman VF900-Cu cooler is used to keep down the heat more effectively than reference cooler. Nonetheless, it cannot run away from dust like any other cooler. You can see that after one month of usage there's a lot of dust clogging the gap between cooling fins, I hate that! Fortunately the fan is removable, all you need to do is just unscrew the 3 screw that set the fan in place with the cooler by using small cross screwdriver. The screw could be easily located by looking from side. After that, unplug the fan cable from the extension.
Close-up view of the dusty cooler
After finish cleaning the heatsink, use some cotton bud dampen with water to clean the fan blades, and it is ready to be installed back into the heatsink. Please note that the screw should not be overly tight as this will increase the vibration generated by the fan to the card itself. This is often overlook by many people and shall be avoided for installing other pc components like harddisk, dvd drive, motherboard to prevent damage.
Close up view of the cooler after cleaning. Clean & clear ^_^
Well, dust is unavoidable regardless whether your case has any fan filter or not, the only difference is that one with fan filter installed will accumulate less dust compare with the one without the fan filter in a given period. Since dust will build up on components surface, it'll affect heat dissipation and eventually shorten components lifespan, and makes your case looks bad too (for cases with transparent side panel). It's advisable that you clean your case at least once every 2-3 months for case without fan filter and 4-6 months for case with the filter. You shall clean it more often if you care about your pc more than average users. For the filter it's better to be cleaned twice in a month since clogged filter would allow less air pass through your computer case, and hence hinder cooling. Graphic card is one of the hottest component inside a system unit, and it should receive extra care on the dust cleaning. Spent a little time to do some housekeeping for your pc and it shall better serve you in long term.
