Methods and devices are provided whereby a controlled personal breathing zone is maintained using temperature controlled laminar air flow (TLA) of filtered air. A substantially laminar, descending flow of filtered air is maintained with a velocity determined by the air-temperature difference between the supplied air and the ambient air t at the level of the personal breathing zone. The air-temperature of the filtered supply air can be carefully adjusted to maintain the velocity-determining difference in air-temperature within the optimum range of 0.3 to 1° C. Thus being able to at the same time displace body convection and achieve comfort.