Extraction and ventilation of 1.2x1.2x2m tent in bedroom.

You’ll be fine you don’t even necessarily need to vent it out to a window a lot of people just pull and push air from the bigger open area of there house! Especially if you have a carbon filter! But it will never hurt to push out a window or pull fresh air the same way! Good luck

Just to be a bit more clear, my extraction ducting is resting on the windowsill next to the open window.. as the fresh air flows into the room it prevents the grow tents expelled air from leaving the room itself, therefor, will the fresh air from the window and the recycled air from the tent 'mix' well enough to ensure my babies get enough co2 for growth.. I know that recycling the air of a growspace is a bad idea but with the constant flow of fresh air mixing with the recycled i wonder if this is 'enough'

yes of coarse you can run it out a window