SEEKIT: Cheers mate,
14:59hrs: MB-35/95. CPU-44/111. GPU-53/127. HDD-30/86.
I had assumed that fans of similar build and size would shift a similar volume of air - ergo, faster spins would move more than a slower item of same size etc. I'd be pleased to be proven wrong. I will then have more options to look at.
My fans do get quite some use, as the home machine goes on first thing in the morning, & stays on till I go to bed. I'm disabled so at home most of the time. Am not into gaming, so no great volume usages.
I do vacuum now & then, & have made a narrow attachment to go on the hose, to get into the nooks'n'crannies.
Temps: I'm in Cornwall, and do get quite warm in the summers. As the machine is in the lounge, I'd love it to be quieter, but not at the expense of the temps. That's as far as I got last time, when I bought the few bits as in the OP.