Question about dust

does excess dust cause a computer to generate more heat?
if so, how much more?

negligible. moreover, dust will generally clump up at the floor effecting nothing.

fan dust is the real problem, especially CPU/GPU fans. they're impossible to clean. I use a leafblower (DANGEROUS).

it's easy to get caught up in the ocd of OHNOEZ DUSTY COMPONENTS but unless you're like Google's cologuys who gives a shit. your real enemies  are wiring, fan directional alignment, and room temperature.