An open architecture HVAC module is disclosed having a housing defining an air inlet and at least two adjacent air outlets. An evaporator and a heater unit are disposed within the housing. A cold air chamber is defined between the evaporator and heater unit, and a hot air chamber is defined downstream of the heater unit. A partition extends into the cold and hot air chambers from an interior surface of the housing between the two adjacent air outlets. The partition is spaced from the evaporator and heater unit. The partition cooperates with the housing to define a first mixing chamber in fluid communication with the first outlet and a second mixing chamber in fluid communication with the second outlet. A blend valve is disposed in each mixing chambers. The blend valves are configured to selectively direct air flow from the cold and hot air chambers to the air outlets.