The modeling and simulation of oven curing in automotive paintshops is very challenging including multiple scales, turbulent air flows, thin boundary layers, large temperature gradients and long curing times. A direct brute force conjugate heat transfer simulation of an oven resolving all time and length scales would be enormously time and resource consuming. It is therefore clear that mathematical modeling must be performed, including separation of scales, and a simplification of the heat transfer coupling. We present a novel approach developed in a research project together with the Swedish automotive industry, which makes it possible to accurately simulate a curing oven with close to real time performance. The simulation results are demonstrated to be in close agreement with measurements from automotive production.