A refrigerator, comprising: a cabinet; a refrigeration system including an evaporator; and an ice-making compartment within the cabinet, the ice-making compartment comprising: a housing defining an inlet aperture on a top portion of the housing and an outlet aperture; an ice storage bin positioned in a bottom portion of the housing; at least one ice tray positioned in the top portion of the housing and over the ice storage bin; an inlet duct in fluid communication with the inlet aperture and configured to direct air into the housing from the evaporator, wherein the inlet duct includes a first branch having multiple channels to direct air to multiple locations on a first surface of the ice tray and a second branch to direct air to a second surface of the ice tray; and an outlet duct in fluid communication with the outlet aperture and configured to direct air from the housing to the evaporator, characterized in that the housing includes a stepped top wall that comprises multiple steps, wherein the steps of the stepped top wall align with the channels of the inlet duct, and wherein a space between the stepped top wall and the at least one ice tray decreases along the direction of the incoming air with each step at a point where the channel directs incoming air towards the ice tray. a cabinet; a refrigeration system including an evaporator; and an ice-making compartment within the cabinet, the ice-making compartment comprising: a housing defining an inlet aperture on a top portion of the housing and an outlet aperture; an ice storage bin positioned in a bottom portion of the housing; at least one ice tray positioned in the top portion of the housing and over the ice storage bin; an inlet duct in fluid communication with the inlet aperture and configured to direct air into the housing from the evaporator, wherein the inlet duct includes a first branch having multiple channels to direct air to multiple locations on a first surface of the ice tray and a second branch to direct air to a second surface of the ice tray; and an outlet duct in fluid communication with the outlet aperture and configured to direct air from the housing to the evaporator, characterized in that the housing includes a stepped top wall that comprises multiple steps, wherein the steps of the stepped top wall align with the channels of the inlet duct, and wherein a space between the stepped top wall and the at least one ice tray decreases along the direction of the incoming air with each step at a point where the channel directs incoming air towards the ice tray. a housing defining an inlet aperture on a top portion of the housing and an outlet aperture; an ice storage bin positioned in a bottom portion of the housing; at least one ice tray positioned in the top portion of the housing and over the ice storage bin; an inlet duct in fluid communication with the inlet aperture and configured to direct air into the housing from the evaporator, wherein the inlet duct includes a first branch having multiple channels to direct air to multiple locations on a first surface of the ice tray and a second branch to direct air to a second surface of the ice tray; and an outlet duct in fluid communication with the outlet aperture and configured to direct air from the housing to the evaporator, characterized in that the housing includes a stepped top wall that comprises multiple steps, wherein the steps of the stepped top wall align with the channels of the inlet duct, and wherein a space between the stepped top wall and the at least one ice tray decreases along the direction of the incoming air with each step at a point where the channel directs incoming air towards the ice tray.