Sammendrag
Requirements, guidelines, and recommendations for exhaust in bathrooms are found in all the Nordic countries, but the stated exhaust volumes differ, and the origin of these seems to be uncertain. The degree of impact of drying time and mold growth conditions is therefore assessed based on different exhaust volumes and floor temperatures in this thesis to find optimal combinations of exhaust and underfloor heating. In this thesis, both constructed experiments and field experiments were used to assess different exhaust volumes and floor temperatures, as well as combinations of these. In the constructed experiments, 36-, 54- and 72 m3/h were used as exhaust volumes, and 22 °C and 26 °C were used as setpoints of the heated floor in standardized shower sequences. In the constructed experiments, relative humidity and temperature were measured over the 23 hours after each shower sequence, and the shower zone was thermographed with time-lapse in certain experiments. In addition, water-saturated wooden bricks were placed on the floor to assess the degree of drying of wood by various experimental parameters and combinations. In the field experiments, measuring equipment was placed in two bathrooms in a student home, where relative humidity and temperature were measured through one week. One of the bathrooms had high floor heating and 36 m3/h exhaust volume, while the other bathroom had medium floor heating and 54 m3/h exhaust volume. For both constructed experiments and field measurements, an analysis of mold growth conditions was performed for each experiment. The results show that higher exhaust volumes result in faster drying time measured in the exhaust. Based on thermography and measurements in the shower zone, high underfloor heating gives up to 3 times faster drying out compared to low underfloor heating. It also appears that the difference in drying time is greater when increasing the amount of ventilation from 36 to 54 m3/h, than from 54 to 72 m3/h. In the constructed experiments, it emerges by analyzing mold growth conditions that both 54 and 72 m3/h of exhaust volume gives less time with favorable mold growth conditions than 36 m3/h. In the field measurements, no favorable mold growth conditions were registered in the bathroom with 54 m3/h exhaust volume, while for the bathroom with 36 m3/h exhaust volume, favorable mold growth conditions were registered for 15 minutes during the measured week. In small bathrooms with underfloor heating and without adjacent outer walls, it may appear from the results that 54 m3/h is a reasonable amount of exhaust that secures the bathroom against mold growth without unnecessary energy consumption. The results also indicates that the amount of exhaust is the most important factor for quickly emptying the bathroom of water vapor, while the floor heating is most important for removing free water on the floor and water in the flooring.