Development Of A Floor Tile With Humidity-controlling Effect To Control Condensation On The Interior Floor

The phenomenon of "Hui Nan Tian"(continuous wet weather)often occurs during the period of season change from winter to spring(generally from February to March)in the hot and humid regions of southern China."Hui Nan Tian" is a phenomenon of dew condensation when the high-humid(nearly saturated)and warm air is contacting with the lower-temperature indoor surfaces.Dew condensation would enable the floor wetted,easy to dirty,seriously affecting the normal life.At present,indoor dehumidification is mainly carried out by mechanical means,which will consume a lot of energy.Therefore,it is of great significance to use a passive method to alleviate indoor floor condensation in the hot and humid region.However,there are no humidification-controlling materials for passively mitigating the indoor floor condensation in the hot and humid regions of southern China.In this paper,by applying the humidity-controlling mechanism of porous humidification materials,a porous glazed floor tile with humidity-controlling function was developed,which is suitable for the indoor floor and can be used to alleviate the indoor floor condensation during the period of "Hui Nan Tian".Nanning was selected as the research object.The humidity-controlling effect of the developed floor tile was investigated under weather conditions(ambient air temperature,outdoor and indoor relative humidity,floor surface temperature)during "Hui Nan Tian" in Nanning.The following four parts were conducted in this study.(1)Many raw materials for preparing the humidity-controlling floor tiles were analyzed from the aspects of chemical composition,composition and function,in order to determine the raw materials and preparation methods.Clay,feldspar and quartz were selected as the main raw materials for the humidity-controlling floor tile,which were mixed and pressed in a certain proportion and then fired at a high temperature.The porous glazing material was fired with ready-made glaze at a temperature of 800-900℃.The pore-making agent was soluble starch.(2)The impacts of the pore-forming agent content on humidity controlling wear resistance and compression resistance of the developed floor tile were analyzed based on comparative experiments.The experimental results show that the moisture content,moisture absorption rate and porosity increased with the increase of pore-forming agent content,while the failure strength decreased with the increase of pore-forming agent content.The hygroscopic rate of the porous glazed layer increased with the increase of the amount of the pore-forming agent,but its smoothness and wear resistance decreased with the increase of the amount of the pore-forming agent.After comprehensive consideration,7.5% and10% pore-forming agents were selected to prepare the substrate and moisture permeable glaze of the humidity-controlling floor tile.(3)The moisture-regulating ability,the duration of continuous moisture-regulating and the moisture-releasing ability in different humidity environments were investigated through the experiments.The experimental results revealed that the moisture-releasing capacity of the developed tile is close to that of the moisture-absorbing bricks under the same environmental condition,and the moisture-regulating ability is better than the latter.The moisture-adjusting time of the developed tile in the same humidity environment is longer than one day,which meets the development goal.(4)Through numerical simulation and measurement,the humidity-controlling effect of the developed tile was discussed under the weather condition during "Hui Nan Tian" in Nanning.The indoor temperature,indoor relative humidity and floor surface temperature were simulated by Design Builder software during the period with "Hui Nan Tian" phenomena in March.An environment with constant air temperature and humidity was created using a box for realizing the weather condition on a "Hui Nan Tian" day in Nanning.The humidity-controlling effect of the developed tile was investigated by placing the test tile in the experimental box.It was found that there is no condensation phenomenon for more than 24 hours,and the humidification effect can be maintained after 24 hours.It can be concluded that the moisture-regulating tile developed in this study has a good moisture-regulating effect in the meteorological environment during Hui Nan Tian,and can be used to alleviate the phenomenon of Hui Nan Tian in the hot and humid region.Furthermore,the application of the developed tile could play a positive role in the development of the green,energy-efficient and healthy buildings in China.