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 . <EOS>