It’s no secret that computers have a tendency to attract dust. You should clean your computer now and then to avoid problems. The biggest threat of dust is buildup in the fans, causing them to spin slower, erratically, or even stop completely. Heat sinks also tend to get stuffed with dust, making them less efficient in removing heat from the components underneath. This typically causes overheating, leading to fans having to spin faster (and thus louder) or CPU might slow down to protect it from the heat. Worst case scenario is that components are damaged or have their life span reduced.
The best way to clean your computer is if you have access to an air compressor, but most people don’t. Cans with compressed air are excellent, but they are fairly expensive and don’t last very long. Often I simply blown the dust away with my mouth. This is however not very effective and quite tiresome for larger objects. But now I have found a new method! My tip is to get your bicycle pump, or better yet a bigger pump like in the picture, with more power and a hose so you can direct the airflow. Take your computer outside and start pumping! Don’t forget to blow inside the power supply, behind panels and other places that also tend to collect dust. It’s hard to get it all out, but you should be able to get most of it in no time!
If you want to avoid dust all together you should start by putting the computer in a place where dust does not gather in the first place. Many computers sit in a corner under the table, which is possibly one of the worst places in regards to this! Furthermore you can add filters in front of the air intakes (usually at the front of the computer). However, these filters must be cleaned regularly or else they might clog up and block the airflow.