AFT Arrow models heat transfer simultaneously with the flow calculation.

By default pipes are adiabatic, but different heat transfer models can be selected such as Convective Heat Transfer and Constant Heat Flux. With Convective Heat Transfer pipes can be assigned insulation and convection coefficient data so as to calculate heat loss/gain.

In addition, heat exchanger junctions offer twelve heat exchanger thermal models. Thermal linking with other heat exchangers is also provided.

Finally, heat addition at compressors can also be modeled.

As heat transfer takes place during the system flow solution, physical properties are dynamically updated based on resulting temperatures and pressures and a system energy balance is performed as part of the simulation.