sPoNiX wrote:

My house is very hot, especially upstairs. Even with the windows open
and a fan blowing it gets hot as the fans just blow the heat round and
round the room. What's needed is somewhere for the heat to go.

I was thinking, could I fit small unducted extractor fans in the
upstairs ceilings such that they blow the heat directly into the loft?
Cooler air would then be drawn in via the windows making the room
cooler.

Is there any problem with blowing air directly into the loft in this
way? Would it cool the upstairs rooms or make additional problems?

sPoNiX

First off you should insulate the upstairs ceilings better. This reduces
heat uptake from the roof space.

Secondly, yes, if you can find a source of cooler air, suck out the hot
and dump it wherever it will leak away - be careful though - if the roof
is already hot, pumping hot air into it isn't going to cool the room if
the insulation between roof and room is so much garbage.

better to arrange an exhaust pipe outside somewhere.