FloCAD is a Thermal Desktop software module that enables a user to develop fully integrated thermohydraulic models for fluid flow and heat transfer. With FloCAD, the mechanics of building fluid flow models is very similar to that of building thermal models, with many of the commands applicable to both types of models. FloCAD models can be free-form, sketchpad style flow network modeling for abstraction and simplification, or they can be geometry-based by including geometric objects such as pipes and vessels. Convection heat transfer can be added between fluid networks and thermal objects for complete pipe flow simulation or the modeling of natural convection.