Home improvement question

Thanks for that info. I did think it was weird that anyone would half way finish a garage in a townhouse. When you walk into the garage, it is cinderblock for the first 10 or so feet, and the final 20 feet or so of garage are paneled walls with a dropped ceiling. We use it as a garage and keep an eliptical machine and stereo in the back of the garage for exercising during the summer.

In the dropped ceiling, there is an air vent to pump in hot/cool air but it is covered in plastic. I just want to hack off that part of the duct and cap it off before it goes into the garage.