I use a small Shop Vac, using the hose to blow air INTO the case, not sucking air OUT of the case. Not all Shop Vacs have the feature where you can insert the hose into the exhaust port of the unit, but if you have one of these, it works great. Just make sure the filter and hose are completely dry or you will end up spraying a fine mist of moisture into the computer (I did that once, luckily it was unplugged so after drying out no damage was done). Also, it is best to do this in the garage or outdoors because a lot of dust, cat hair, etc. will be blowing all over the place.