An oven for heating a coating on a substrate, such as a painted vehicle body, including a first zone having radiant tubes and shields above the tubes and a second zone including side heat chambers having nozzles directing heated air onto a coated substrate and a hold zone. The radiant tubes may include a first linear portion extending through the oven and return loop beneath the substrate to conserve energy and sill ducts directing heated air against the underside of the vehicle body. The temperature is controlled by sensors contacting the radiant tubes and a proportional integral control system.