5 hours and for any person with Do-it-yourself skills it is not difficult plenty of. It's lowered noise noticeably Even with not becoming within the advised length from the existing window. It is usually invisible! I've attached shots and it's hard to see the additional device! Hugely encouraged this company. https://kameronemoqo.tkzblog.com/34435857/the-smart-trick-of-window-retrofit-that-no-one-is-discussing