A method and system for treating objects, the objects are conveyed through a treatment cabin and treated in a treatment space. During treatment solvents are released. Cabin air flows through the treatment space, which absorbs solvents and is discharged as process air from the treatment space. At least one proportion of the process air charged with solvent is recycled in the treatment space and at least one proportion of the process air can be discharged as exhaust air. Fresh air is fed to the treatment space, which contributes to the cabin air, such that the cabin air includes a circulating air proportion and a fresh air proportion. The solvent concentration is captured in the cabin air and/or in the process air and/or in the exhaust air and the circulating air proportion and the fresh air proportion of the cabin air are regulated as a function of the captured solvent concentration.