Since 1985 I am daily occupied with all aspects of climate control, mainly in pig sties. The greater part of my work consists of the visiting of farms that have problems which are possibly caused by a wrong way of ventilation. I also give advice to farmers who are planning new building and rebuilding. Moreover, courses and lectures are given for the benefit of e.g. pig-farmers and advisers. Since 1995 I am also the chairman of the Climate Platform for Pig-breeding.