The livestock rooms with the systems for feeding dry feeds using feeder pipelines are characterized by a relatively high concentration of dust. The studies on the shaping of artificial lighting intensity were carried out in an experimental, non-bedding pig fattening house. In order to improve the lighting, the animal room was modernized by lining the ceiling and walls with aluminum foil. It constitued a reflector screen when light was on, which, however, over time became covered with dust coming from the mechanically fed dry feeders. For the assessment of brightness in the production hall, five equally spaced measuring stations were placed in the pens and five similarly spaced stations were set in the corridor. The intensity of lighting (brightness) was measured with the L-20A lux-meter. The measurements were carried out after a six-month use of the liner, when it was significantly contaminated with the dry fodder particles. As part of operational tests, the differentiation of brightness between the individual stands and gradual changes in lighting at various stages of aluminum foil cleaning were checked: washing the external wall with detergents, washing all the walls in the room and the entire interior, including the ceiling was carried out. Before wet cleaning the reflector screens, a significant differentiation of the brightness between the stands in the pens was observed – it ranged from 134.1 Lx to 176.0 Lx, which indicates uneven pollution of the internal surfaces of building partitions. Similarly, significant discrepancies in the lighting intensity were found on the corridor floor. The values ranged between 50.3 Lx and 65.8 Lx. When washing the next partitions, the average illumination values in the pen area dropped unexpectedly, and the final drop after removing the dust from all the walls and ceiling was 2.8%. A similar tendency was observed in the communication-drive corridor. In this area, the brightness decreased by as much as 4.1%. The reason for the decrease in visual comfort was the mattifying of screens caused by grinding of particles during washing. Therefore, it would be necessary to undertake the research on the removal of dust from the reflector screens using another method, for example mechanical dusting.