The invention relates to a housing (1) for a fluid machine, in particular for a radial fan (2), comprising at least one housing part (3), wherein the housing part (3) has at least one inlet opening (7), wherein the housing part (3) can at least partially delimit a fluid chamber (8) for receiving at least one fan wheel (9), and wherein the inlet opening (7), at least in part, has a curved inlet surface (11). To produce a housing (1) for a fluid machine, in particular a housing (1) for a radial fan, preferably for use in a car seat and offering reduced noise emission together with good performance, the curved inlet surface (11) has at least in part the form of a logarithmic spiral in cross-section, and/or at least one guide element (21) extends from the inlet surface (11) towards a central axis of the inlet opening (7), and/or on the inside (17) of the housing part (3) there is provided a circumferential recess (25) which at least partially circumferentially surrounds the inlet opening (7) and/or a circumferential projection (6) which at least partially surrounds the inlet opening.