A:Answer Yes, left side is fine as long as the hose reaches and is not pulling on the window insert.
It may take (2) to get the hose attached to the spacer. Before you install the hose vent, measure the rectangular spacer so that it fills the open space in the window. If you are using the extender piece, use a philips head screw driver on the (2) screws to hold the length you need in place.
REMOVE FROM THE SPACER FROM WINDOW, extend an end of the hose fully and screw on the round attachment (with the wire screen), several turns so it is securely attached to the end of the hose, next, line up the (3) "L" shaped tabs with the slats on the spacer, insert and twist to lock in place (may take 2 people). Install spacer (with hose attached) in the window, close the window tight against the side flanges of the spacer, there are screws if you need to secure it more. I have not used the screws the window holds it fine.
Last step, screw on the other round end attachment, several turns on the hose until it lines up with the back of the unit. Slide it to place.
Hope that helps!