By the nature of an editing application you can't avoid rendering processes which will fill your render folder. You can delete that files and only the parts with effects in your sequence which you are currently working on will be rendered again. This will shrink the amount of needed space.
How to do that, in
THIS Post..
BTW - It looks like Hans has won the Euromillions Lottery, by the look on his Face in his Avatar.
ADDED - Both Posting at same time. You still need to Delete the Hidden Render Folder, as per my Link. Which could clean several GB off your HDD.