What a great idea. Not sure how well it would hold with the diagonal shape of my heasink but something to think about for the future. Hera if your fans are really bothering you and you have the money to replace them then I'd say it's worth doing. QuietPC sells PC stuff specifically designed to be quiet. If you're lucky your fans will all be fixed standardly with screws so you can just find fans of the same size and swap them out. The fan section there has tables telling you how many decibels they are and how fast they spin which is helpful. While you want as quiet a fan as possible it's usually important not to replace a fast spinning fan with a slower one. If it’s your actual CPU cooler that’s the noisemaker then you’ve got tonnes of options, even up to a completely fanless cooler, depending on how much space you have.