It kinda has to do with what we're talking about so I won't start a new thread: what's your opinion about PVC windows, smokes?
Can't stand them and more and more of London is now becoming conservation areas where you are not allowed to install them, you have to use timber ones.
They work well for sure and are cheap to manufacture, but if you have a house over 50 years old they will definitely spoil it's look. They are best suited to more modern houses .
PVC double glazed.
"whistles" only if the wind blows at it.
cannot see any tears or rips in the opening window seal
It can be tricky to figure out what is going on there, it could even be one of the mitres is gappy and the wind is whistling down the metal box section. You could try some of the adhesive seals to pad out the existing as it sounds like a small gap may be evident, and it is doesn't fix it you can rule that out which won't leave much.
Do they have a vent so stop condensation in the sealed unit?
