I am in the middle of my first design to be printed on my new printer. I am designing a fan duct and ave designed it in blender. My question is there a way to add thickness to the walls of the design easily? Eac wall is only one vertices thick and I am not sure if that is thick enough for printing. Thanks.

1 vertice will not be thick enough, 3d world is diffrent from real world.... in 3d world you can see a vertice in real life a vertice = 0, there is no thickness to it. You can try downloading and installing the 3d printing package for blender, but for now an easy way to add thickness is to extrude. you also need to make sure you scale everything approprialty in the worlds tab choose metric and scale to .01