Ive just bought an air conditioner and it has a pipe out the back of
it which is about 6" diameter that blows out the hot air and needs to
vent to outside. Currently I have got it dangling out the window, but
this is far from ideal as the window is up high and the pipe is on
full stretch to reach it and the pipe itself gives off quite a bit of
heat and the window needs to be open etc etc.

Ideally I need to cut a 6" hole in the side of my house and put some
sort of vent thing in. The only way I can think of doing this is to
draw the circle on the wall and then drill lots of little holes round
the circumferance.

Is there a better way of doing this? I looked at a large bore diamond
cutter from HSS, but they wanted about £70 a day to hire it!

Any help greatly appreciated!

David Bevan
http://www.davidbevan.co.uk

PS - I take it its ok to put a 6" hole in an external (structural)
wall?