Aspirated - Vesda sytems, done them as well, you also get the systems as well where the detector sits in it own enclose sampling the air at high level.My mate has worked on various different systems. Aspirated, Gas systems etc. He’s worked on some new built schools and football stadiums.
But at the end of the day I'm happy being a proper spark because fire system intaller's can't step up to do my sparky work, but I can step down and do their work if you know what I mean.