Investigating the Sorption Isotherms and Hysteresis of a Round Perforated Brick Using Newly Developed Models

Abstract

This article deals with the hygrothermal behavior of round perforated brick including hysteresis effects. It aims at examining the effect of temperature on sorption isotherms and hysteresis of this product, reducing the energy consumption of the buildings, reinforcing the constructional economy and the inhabitant’s comfort as well as offering a hygrothermal description of this product that has never been previously investigated. To achieve this, we have carried out an experimental study to determine the sorption isotherms and the hysteresis in five different temperatures (10, 23, 30, 40, and 50 °C). Twelve equations have been tested against the experimental isotherms in order to find the optimal one. After that, three models were tested in order to develop a personal model; the latter explains the real effect of the hysteresis phenomenon on hygrothermal behavior of the studied product. To validate the mathematical model, two methods were applied to calculate the isosteric heat. The obtained results revealed a significant influence of the increase in temperature on the hygrothermal behavior in which a decrease in the equivalent water content was found. Moreover, the developed experimental model is based on Oswin’s model describing the dependence of temperature on the sorption characteristics of round perforated bricks. Furthermore, the Huang model was found to be the best compared with the other models with a regression factor (R2) of 0.990. The validation of the results using the isosteric heat parameter has confirmed that the suggested models demonstrated a perfect presentation of the sorption isotherms and the hysteresis phenomenon of the round perforated brick.

Keywords

• hygrothermal behavior
• round perforated brick
• sorption isotherm
• hysteresis