We’ve repaired a lot of computers and can tell you first hand smoking around your PC can shorten its lifespan. The internal parts get coated with a brown, sticky residue and can no longer cool down properly. We’ve replaced many cooling fans and other parts that burned out prematurely. We’ve also seen monitors and other peripherals fail that were also covered with the same sticky substance. Smoking in the same room with your PC may not be the best choice. Here’s a link to a smokers computer.