What is the ruling on marrying an engineer who works in the maintenance of refrigeration and air conditioning units in a hotel that serves alcohol, knowing that his work is not related to selling, buying, or serving it?

Your nephew is not permitted to work in a hotel where alcoholic beverages are served, even if his work is far removed from direct involvement with them. This is for the following reasons:

1. Cooperation in sin and aggression: As Almighty Allah says: "And do not cooperate in sin and aggression." His work in maintaining refrigeration and air conditioning systems is considered cooperation, as these are used for cooling and creating an atmosphere for those engaged in immorality. 2. Mixing salary with revenues from alcohol and forbidden acts: The money he receives contains a significant portion from illicit revenues. 3. Witnessing forbidden acts: He will not be safe from witnessing forbidden acts and inadequately dressed women who frequent these places. 4. Habituation to sin: Working in such places leads to habituation to sin and a weakening of its dislike in the heart, which may lead to committing it. 5. Sanctioning evil and abandoning its denunciation: This work is considered a sanctioning of evil, and the Prophet, peace and blessings be upon him, commanded changing evil.

Based on this, you should not marry your daughter to this man unless he leaves his job at this place.