Cooling upstairs with a single window unit a/c?

Question

The window unit is downstairs and I want to know if the upstairs windows should be up or down for efficient cooling of the entire house

Answer 1

keep window down and use a powerful fan to push the air up the stairs remember cool ai sinks and hot air rises

Answer 2

Pretty unlikely the window unit will go up a floor. The problem is air flow, not BTU. What capacity is the unit?