Maciej Zielenkieiwcz wrote:

The (reasonably) simple solution to this is to replace glass in windows
with some other material. This goes quite simple if you have modern
plastic windows, then you can pull the glass out, measure the dimensions
and get a plastic or mdf board of proper size. Then inser it in place
of glass. If plastic is too transparent (depends on exact kind of
plastic, thickness and colour), paint it with black paint.

After that you can drill a hole in it, to which you attach a pipe.
Choose a size which will accomodate a standard kithen ventilator. Buy a
U-shaped pipe (probably you'd have to assemble it from pieces) and paint
inner surfaces black. Also paint fan blades.

The fan should be installed to blow air out of the room,

Not really. You should blow air into the room through an air filter to
remove dust entering the room. If you blow the air out of the room, the room
will be at a partial vacuum and dust will get in from every leak.

so that it
won't pollute air in the house. If you want fresh air from the outside,
attach second pipe but without the fan, it should allow for enough cool
breeze and there would be less dust.

An air conditioner would be a possibility, but light could still get
in.

Standard air conditioner would not provide you with ventilation, it would be the
same air all the time, only cooler. Which means inhalating some toxic
fumes from your chemistry, which is not advisable.

A standard air conditioner will provide you with ventilation. Most have a
lever that controls a small door to the outside. If you need ventilation,
though, you may not find this to be enough.