An appliance includes a cabinet; a first compartment; and a second compartment. The first compartment and the second compartment are separated by a horizontal mullion. The cabinet also typically includes a coolant system that has: a single compressor for regulating a temperature of the first compartment and a temperature of the second compartment operably connected to at least one evaporator; a shared coolant fluid connection system; and a coolant fluid spaced within the shared coolant fluid connection system used to regulate both the temperature of the first compartment and the second compartment. The compressor can provide the shared coolant at at least two different pressures to at least one evaporator using the shared coolant fluid connection circuit. The ratio of the substantially steady state heat gain for the first compartment to the substantially steady state total heat gain for the overall cabinet is about 0.65:1 or greater.