# Impact of Temperature on the Moisture Buffering Performance of Palm and Sunflower Concretes
## 1 Introduction  
Energy-efficient, insulated and poorly ventilated buildings can have a bad indoor air quality due to too high or too low relative humidity levels. An uncontrolled relative humidity increases the risk of exposure to bacteria, viruses and mold. These can have negative consequences on the health of occupants and reduce the comfort of indoor environments. Air conditioning systems permit maintaining optimal relative humidity levels but consume a lot of energy and increase the cost of bills. The moisture buffer capacity can moderate the relative humidity within a building, resulting in a naturally improved air quality and reduced energy consumption. Historically, the first research on the moisture buffer capacity was carried out at the Institute for Building Physics in Fraunhofer (Germany) and Lund University (Sweden) in 1960. Characterization of the moisture buffer value was carried out under dynamic conditions of relative humidity, hence the establishment of the standard for moisture buffering for experiments [1, 2, 3, 4]. Following this method, the Padfield method [5]was developed which defines the moisture buffer value as a non-intrinsic property by making an analogy with thermal capacity [5]. Others methods have recently been developed by researchers such as the Japanese Industrial Standard [6], the NordTest project [7] and the ISO standard [8]. These methods consist in varying the relative humidity periodically with square or cyclic functions. These methods highlight the parameter of sorption of water vapor to characterize the moisture buffering value. It is predicted that these studies on the characterization of the MBV of building materials will remain a primary interest in order to refine the design of high energy-efficient and sustainable buildings. In the literature, various authors have studied moisture buffering in the construction sector. Reviews have presented various experimental and numerical methods to quantify moisture buffering effects and their impact on the building scale (indoor RH and energy reduction). Research has been conducted to elucidate the physical, chemical and biological characteristics of building materials that have particularly high moisture buffer values [9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22]. One of the meta-analytical studies looked to see which properties are characterized in tandem with the moisture buffer value and which may be correlated with it [23]. These properties are: intrinsic physical properties and hygric properties dependent on relative humidity. The intrinsic physical properties are thickness, density and porosity. The study revealed that a simple least squares regression shows no relationship between thickness and the MBV. This may explain the fact that the majority of tests for the characterization of the MBV are based on the NordTest method [7]. The NordTest method is more used and is currently the main standard for characterizing the MBV of building materials. This method requires a sample thickness that is superior to its penetration depth. Moreover, a study carried out by [PERSON] et al. (2018) [24] on determining the optimum plaster thickness to dampen the indoor relative humidity showed that the MBV increases linearly with the thickness when it is lower than the penetration depth of the material. By deduction, analysis of the literature data has shown that a thickness higher than the penetration depth is a physical property of the material and is not a significant factor that can influence the value of the MBV. A porous medium is characterized by the combination of a solid matrix and a pore space that can be occupied by one or more fluids (liquid or gaseous form) [25]. The structure of porous materials is characterized by bulk density and porosity. These porous materials have a density which depends on their porosity. High porosity leads to a light material [26; 27]. [PERSON] and [PERSON]'s [23] analysis showed that there is a strong correlation between porosity and the MBV with an R\({}^{2}\) of 0.46.