WOW!!! I want to come move in with you, you must have some clean air. LOL would keep my computer nice and clean and no dust to make my asthma/allergies bad. Do you have a big air cleaning system in your house or something? I'm gonna have invest in whatever it is that kept your computer that clean, although I guess it could be that the case you have looks pretty well sealed which is prolly why you're having heating issues now.

I don't know what to say
well we do have good ventilation in our house, but also the PC is on the 3rd floor where the roof windows are always open so fresh air is everywhere here

LOL, well thats cool. I just cleaned my case a couple days ago and I bet if I opened it up now it would be way dirtier than yours was. STUPID DUST!

so, after multiple replies from different people, I decided to buy this CPU Cooler Zalman CNPS9500, and this VGA Cooler Zalman VF700-Cu.
The only one thing left is a case. You said I should get a new case / better ventilation, but I think I don't actually understand how to make better ventilation and how would a case with better ventilation look like... can you suggest me something ? and of course I can buy another fan and put it on my upper side of the case, but people say that I should have a front intake fan, which I can't have in my current case