If you have sliding sashes then a lot of these units come with a kit that is a doddle to fit. In fact you don’t “fit” anything, the sash traps the panels and you open it up to width of window.
Not seen any that work with side hung casements or veluxes BUT….. you don’t really need to seal every window for the unit to work. Makes them slightly less efficient but does job fine. We have ours out the French doors of the loft juliet balcony and works fine.
Be warned though…. These are VERY noisy!!! Turns into white noise at night but I’d struggle to work with one on in my office |