A. Typically 10-15 minutes in mild weather. The closer you get to the max design temperature in heating (0 Degrees) or cooling (90 Degrees) the longer the run cycle will be.

A. You can close some vents in unused areas of the home but be aware that your insulation is the exterior walls, if you let the room get too warm or cool you will still need to overcome that in the adjoining rooms. Closing off too many vents may also cause issues with the furnace or air conditioner.