Pre-engineered rooftop unit incorporates a total enthalpy core that provides both sensible and latent heat transfer and meets ASHRAE 90.1 minimum efficiencies. As the enthalpy core has no moving parts, the need for mechanical maintenance and repair is greatly reduced. The unit is ideal for commercial, institutional, and industrial applications requiring low cross leakage and minimal maintenance. Heating and cooling options are then provided downstream of the enthalpy core to provide additional tempering and dehumidification.