Not necessarily so. I use a big case (Fractal Design R series), with 4 * 140mm fan. The case has thick noise insulation, and the big fans turn (always) very slowly (500rpm, just above stalling) so it's completely inaudible.
A lot better that the tiny fan of a laptop that drives everyone around crazy as soon as you move the mouse :-)
Liquid cooling as quieter than air is debatable. Liquid cooling has pumps that make noise. Personally I am going with air.
Furthermore, I'm not sure how a laptop would be intrinsically quieter than a comparable desktop. In a desktop have more control over mitigating the noise.
A lot better that the tiny fan of a laptop that drives everyone around crazy as soon as you move the mouse :-)