Allied 4 Ton Upflow/Horizontal Constant Torque ECM Air Handler with R-454B Refrigerant This 4-ton air handler is engineered for upflow and horizontal installations, offering versatile configuration for residential and light commercial HVAC systems. It features a Constant Torque ECM blower motor for energy-efficient and quiet airflow performance. The unit includes an Omniguard coil for superior corrosion protection, mechanical or brazed line set connections, a check and expansion valve, and a factory-installed TXV for precise refrigerant control.