Increase In Relative Humidity Research Articles

Field testing and numerical modelling of fog production and control in the construction of mountain tunnels

Fog frequently appears in the portal area of mountain tunnels under construction in cold seasons because of the vast air temperature and air humidity differences between the inside and the outside of the tunnel. It consequently reduces visibility and causes accidents in the construction of mountain tunnels. In this study, field test on air temperature, air relative humidity, wall temperature and air velocity was initially performed in an inclined shaft of a mountain tunnel under construction in a typical winter day. The atmospheric temperature was −2 °C and fog was observed within the range of 550 m from the portal in the shaft. The test results show that the longitudinal air and wall temperatures have a linear increase, and the lowest air and wall temperatures are 16.8 °C and 14.9 °C at the portal, respectively. Furthermore, fog disappears when the air relative humidity is lower than 99% in the inclined shaft. Next, a computational fluid dynamics (CFD) model, solving the species transport and energy models, was established to reproduce the test. The comparison of the air temperature shows a good agreement. The fog lengths in the inclined shaft are 550 m for the test and 600 m for the simulation. This CFD model was then employed to study the effects of the inflow air relative humidity and the wall temperature on fog production and distribution in the inclined shaft. The results show that fog is produced when the inflow air relative humidity is above 86.6%, and the fog length increases significantly with the increase of the inflow air relative humidity. Additionally, the fog length also increases with the decrease of the wall temperature when the wall temperature at the portal is lower than 16.9 °C. An insulation layer imposed on the wall is accordingly proposed and its length is suggested over 50 m longer than the fog length to prevent fog production.

Impact of temperature and relative humidity on the transmission of COVID-19: a modelling study in China and the United States

ObjectivesWe aim to assess the impact of temperature and relative humidity on the transmission of COVID-19 across communities after accounting for community-level factors such as demographics, socioeconomic status and human...

Micro-Climate Conditions, Weed Diversity, Flowering and Yield of Young Cacao Plants as Affected by Shade Regimes

Experiments were conducted in 2015/2018 in two cacao plots established in 2012 and 2013 in Akure, Nigeria to investigate micro-climate conditions, weed densities, flowering and yield of cacao as affected by shade regimes. Established cacao plots under three plantain (Musa spp) shade regimes consisting of No-shade, Moderate and Dense shade were used. Air and soil temperature, relative humidity and Photosynthetic Active Radiation (PAR), weed population and species diversity, cacao flowering and pod production were measured. From the results, air and soil temperature measurements under No-shade plots had a significantly higher mean values (32°C) and soil (28°C) compared with moderately shaded [air, 30°C and soil, 26.5°C] and densely shaded [air, 30°C and soil, 26°C] plots in2015 and 2016 measurements but under 2017 measurements, no significant difference in the soil temperature of the plots under dense shade, moderate and the no-shade which were ascribed to canopy close-up of the cacao that led to reduced transmitted light through the canopy to the understories species. The vigour of weeds under no-shade plots were significantly higher compared with dense and moderately shaded plots. In 2013 established cacao plot, flower production was higher significantly in no-shade compared with those in moderate and dense shaded cacao plots in 2015 and 2016 measurement. Pod production under No-shade were significantly higher compared with other treatments in 2016 and 2017. Cherelle wilt rate was higher in shaded plots compared with the no-shade plots. Pod yield parameters were significantly higher under No-shade plots compared with shaded treatments during the three years of data measurement. Air temperature between 30°C to 33.7°C during flowering and fruit/pod setting was found to have positive influence on bean yield in cacao. The study concluded that excessive shade decreases yield of cocoa, while increases in temperature and relative humidity boosts some physiological processes for pod production in Cocoa

On the Origin of Supercontraction in Spider Silk.

Spider silk is a protein material that exhibits extraordinary and nontrivial properties such as the ability to soften and decrease its length by up to ∼60% upon exposure to high humidity. This process is commonly called supercontraction and is the result of a transition from a highly oriented glassy phase to a disoriented rubbery phase. In this work, we derive a microscopically motivated and energy-based model that captures the underlying mechanisms that give rise to supercontraction. We propose that the increase in relative humidity and the consequent wetting of a spider silk have two main consequences: (1) the dissociation of hydrogen bonds and (2) the swelling of the fiber. From a mechanical viewpoint, the first consequence leads to the formation of rubbery domains. This process is associated with an entropic gain and a loss of orientation of chains in the silk network, which motivates the contraction of the spider silk. The swelling of the fiber is accompanied by the extension of chains in order to accommodate the influx of water molecules. Supercontraction occurs when the first consequence is more dominant than the second. The model presented in this work allows us to qualitatively track the transition of the chains from glassy to rubbery states and determine the increase in entropy, the loss of orientation, and the swelling as the relative humidity increases. We also derive explicit expressions for the stiffness and the mechanical response of a spider silk under given relative humidity conditions. To illustrate the merit of this model, we show that the model is capable of capturing several experimental findings. The insights from this work can be used as a microstructural design guide to enable the development of new materials with unique spider-like properties.

Effect of Increased Cabin Recirculation Airflow Fraction on Relative Humidity, CO2 and TVOC

In the CleanSky 2 ComAir study, subject tests were conducted in the Fraunhofer Flight Test Facility cabin mock-up. This mock-up consists of the front section of a former in-service A310 hosting up to 80 passengers. In 12 sessions the outdoor/recirculation airflow ratio was altered from today’s typically applied fractions to up to 88% recirculation fraction. This leads to increased relative humidity, carbon dioxide (CO2) and Total Volatile Organic Compounds (TVOC) levels in the cabin air, as the emissions by passengers become less diluted by outdoor, dry air. This paper describes the measured increase of relative humidity, CO2 and TVOC level in the cabin air for the different test conditions.

Experimental study of moist air condensation outside three-dimensional finned tubes with different fin parameters

The condensation of moist air is a common phenomenon in daily life and industry, and increasing its heat transfer coefficient has always been a hot spot in research. Three-dimensional (3-D) finned tube is an effective heat transfer enhancement element and its fin parameters have an important influence on the enhancement result. This study carried out experiments using orthogonal design and Taguchi method to determine the influence of 3-D fin parameters on moist air condensation. The contribution ratios of axial fin spacing, fin height, fin width, and circumferential fin spacing on the heat transfer coefficient were obtained and analyzed in detail. Meanwhile, the photos of condensation processes were obtained. Experimental results show that all the heat transfer coefficient increased with the increase of relative humidity (RH) or the decrease of cooling water inlet temperature. Besides, all the 3-D finned tubes had higher heat transfer coefficient compared with smooth tube. The contribution ratio of fin height on the heat transfer coefficient was the highest, which can be 75.7% at most. Besides, the contribution ratio of axial fin spacing increased from 10.1% to 24.0% with the increase of RH. The optimal parameters combination of 3-D fins within the range of this experiment was also recommended. The results obtained in this study can provide guidance for the design and optimization of 3-D finned tubes used in moist air condensation.

Characteristics of HONO and its impact on O3 formation in the Seoul Metropolitan Area during the Korea-US Air Quality study

Photolysis of nitrous acid (HONO) is recognized as an early-morning source of OH radicals in the urban air. During the Korea–US Air Quality (KORUS-AQ) campaign, HONO was measured using quantum cascade - tunable infrared laser differential absorption spectrometer (QC-TILDAS) at Olympic Park in Seoul from 17 May, 2016 to 14 June, 2016. The HONO concentration was in the range of 0.07–3.46 ppbv, with an average of 0.93 ppbv. Moreover, it remained high from 00:00–05:00 LST. During this time, the mean concentration was higher during the high-O3 episodes (1.82 ppbv) than the non-episodes (1.20 ppbv). In the morning, the OH radicals that were produced from HONO photolysis were 50% higher (0.95 pptv) during the high-O3 episodes than the non-episodes. Diurnal variations in HOx and O3 concentrations were simulated by the F0AM model, which revealed a difference of ~20 ppbv in the daily maximum O3 concentrations between the high-O3 episodes and non-episodes. Furthermore, the HONO concentration increased with an increase in relative humidity (RH) up to 80%; the highest HONO was associated with the top 10% NO2 in each RH group, confirming that NO2 is one of the main precursors of HONO. At night, the conversion ratio of NO2 to HONO was estimated to be 0.88×10−2 h−1; this ratio was found to increase with an increase in RH. The Aitken mode particles (30–120 nm), which act as catalyst surfaces, exhibited a similar tendency with a conversion ratio that increased along with RH, indicating the coupling of surfaces with HONO conversion. Using an artificial neural network (ANN) model, HONO concentrations were successfully simulated with measured variables (r2 = 0.66 as an average of five models). Among these variables, NOx, aerosol surface area, and RH were found to be the main factors affecting the ambient HONO concentrations. The results reveal that RH facilitates the conversion of NO2 to HONO by constraining the availability of aerosol surfaces. This study demonstrates the coupling of HONO with the HOx-O3 cycle in the Seoul Metropolitan Area (SMA) and provides practical evidence of the heterogeneous formation of HONO by employing the ANN model.

Structure and Facile Synthesis of Proton-Conducting [Fe(CN)

Proton-conducting materials are a key component of proton exchange membrane fuel cells (PEMFCs) and the advantage of clear structural information in crystal materials offers a pathway for the investigation of the proton-conducting mechanism and pathway. In this work, a new Cd2+ coordination polymer material (compound 1) with the formula {[Cd3(bipy)3(H2O)4][Fe(CN)6]2·2H2O·2(bipy)}n was successfully synthesized by a solution diffusion method and its proton conduction ability was further determined. Crystal structure analysis confirms the coordination of [Fe(CN)6]3–, 4,4′-bipyridine, and H2O molecules to Cd2+ in the three dimensional structure of compound 1. Also, we confirmed that compound 1 of 500–800 nm particle size could be synthesized on a large scale by a facile stirring method. Proton-conductivity analyses revealed that compound 1 shows a water-mediated proton conduction behaviour because the conductivity increased apparently with the increase of relative humidity. Further investigation shows that the highest proton-conductivity of 8.36 × 10−4 S cm−1 was observed at 60°C and 95 % relative humidity, and the mechanism analysis suggests a Vehicle mechanism exists in the proton conduction process of compound 1.

Behavior of the Average Concentrations As Well As Their PM10 and PM2.5 Variability in the Metropolitan Area of Lima, Peru: Case Study February and July 2016

This research focused on analyzing the behavior of the hourly average concentrations of PM10 and PM2.5 in relation to vehicular traffic, as well as the effect of relative humidity on these concentrations. Measurements of hourly particulate matter concentrations were recorded by the National Meteorology and Hydrology Service of Peru (SENAMHI) at five surface air quality stations. The profiles of PM10 concentrations are related to traffic behavior, showing high levels of concentrations at peak hours, while the PM2.5 profiles are flatter and better related to traffic in February (summer). The decrease in relative humidity between 80 to 65% in the mornings has a greater effect on the increase in PM10 and PM2.5 concentrations in February than in July (winter), and the increase in relative humidity between 65 to 80 % in the afternoon, it has a greater effect on the decrease in the concentration of PM2.5 in February than in July. The air quality in the north (PPD and CRB stations) and east (SJL station) of the Metropolitan Area of Lima (MAL) are the most polluted. The factors that relate PM10 concentrations with the Peruvian standard in February at these stations were 2.79, 1.78 and 1.26, and in July 2.74, 1.28 and 1.36 respectively. The highest and lowest variability of PM10 and PM2.5 in February and July occurred in the northern area (PPD and SMP stations).

Changes in Sensitization Rates In Patients with Asthma and/or Rhinitis in China between 2008 and 2018: A National Cross-Sectional Study

Background: Little is known about the changes in allergen sensitization in China secondary to the rapid economic growth over the past decade. We aimed to compare the differences of sensitization rates in patients with asthma and/or rhinitis in China between 2008 and 2018. Methods: This study analyzed cross-sectional data from national surveys conducted in China in 2008 and 2018. After finishing the questionnaire, participants underwent serum specific IgE measurement. A total of 2322 and 2798 patients were enrolled in 2008 and 2018, respectively. The significance of differences in sensitization rates among four regions of China were assessed. Correlation analysis was used to identify the associations of sensitization with climate change and planting of the Artemisia desertorum between the two surveys. Results: Compared with 2008, the general sensitization rate to mites significantly increased in 2018, and it ranked highest among all tested allergens. Sensitization to pollens, especially those of Artemisia vulgaris, showed the greatest increase in the north, with sIgE grades 4–6. From 2008 to 2018, an increase in Dermatophagoides pteronyssinus sensitization was significantly associated with the increase in relative humidity (r=0.54, P=0.037). The increase in Artemisia vulgaris sensitization was significantly associated with the increase in Artemisia desertorum planting area (r=0.67, P=0.006) and with a decrease in rainfall (r=−0.59, P=0.021). Conclusions: House dust mites remain the most important allergen in Chinese individuals with asthma and/or rhinitis. Pollen sensitization dramatically increased in the northern China. The increases of sensitization to dust mites and Artemisia were related to the increase of humidity and planting of Artemisia desertorum respectively. Funding Statement: This study was supported by the Precision Medicine Research of the National Key Research and Development Plan of China (grant no 2016YFC0905800). Declaration of Interests: We declare no competing interests. Ethics Approval Statement: The study protocol was approved by the ethics review board of each study center. All the participants gave written informed consent to participate in the study.

Influence of Meteorological Factors on the COVID-19 Transmission with Season and Geographic Location.

The purpose of this study is to investigate whether the relationship between meteorological factors (i.e., daily maximum temperature, minimum temperature, average temperature, temperature range, relative humidity, average wind speed and total precipitation) and COVID-19 transmission is affected by season and geographical location during the period of community-based pandemic prevention and control. COVID-19 infected case records and meteorological data in four cities (Wuhan, Beijing, Urumqi and Dalian) in China were collected. Then, the best-fitting model of COVID-19 infected cases was selected from four statistic models (Gaussian, logistic, lognormal distribution and allometric models), and the relationship between meteorological factors and COVID-19 infected cases was analyzed using multiple stepwise regression and Pearson correlation. The results showed that the lognormal distribution model was well adapted to describing the change of COVID-19 infected cases compared with other models (R2 > 0.78; p-values < 0.001). Under the condition of implementing community-based pandemic prevention and control, relationship between COVID-19 infected cases and meteorological factors differed among the four cities. Temperature and relative humidity were mainly the driving factors on COVID-19 transmission, but their relations obviously varied with season and geographical location. In summer, the increase in relative humidity and the decrease in maximum temperature facilitate COVID-19 transmission in arid inland cities, while at this point the decrease in relative humidity is good for the spread of COVID-19 in coastal cities. For the humid cities, the reduction of relative humidity and the lowest temperature in the winter promote COVID-19 transmission.

The Role of Structure Canopy of Terminalia Catappa Linn. on Light Penetration and Decreasing Ambient Temperature as Climate Change Mitigation

Terminalia catappa (Tropical almond) is a tree that usually grows on the seashore. this tree has a shady canopy. This tree is usually planted as an ornamental plant or a shade plant on the side of the road. The presence of the Terminalia catappa tree can provide coolness if the tree is planted in the garden or in the yard or along the roadside. This research was carried out in areas around East Kalimantan, at the sampling location (Balikpapan City, Samarinda City, Tenggarong Ciyt), 25 trees Tropical almond were set in each city which were used as the test samples trees. Data taken includes a) data on physical environmental characteristics including light intensity, ambient temperature and humidity under the canopy performed and out of canopy on each tree sample, and b) data on morphological characteristics (location, height, diameter at breast height, and shape / width of crown ). The relationship between the volume, light penetration and decreased ambient of the tropical almond tree canopy on light penetration under and in the out area of the canopy of the tropical almond tree indicated that there was an effect of the volume of the tropical almond tree canopy on light penetration and there was an effect of light penetration of the tropical almond canopy on a decrease in ambient temperature. The relationship between light penetration and increase of relative humidity indicated that there was an effect of light penetration of the tropical almond canopy on a increase in relative humidity.

Surprising Changes in Aerosol Loading over India amid COVID-19 Lockdown

Using ground-based and satellite observation along with aerosol reanalysis products, we show a widespread reduction in aerosol loading over the Indian subcontinent during the COVID-19 (COronaVIrus Disease 2019) lockdown. The pre-lockdown and lockdown period considered in the present study is 20th February–20th March 2020 and 24th March–22nd April 2020. In terms of aerosol optical depth (AOD), loading has reduced up to 40% over the most populated region of India. However, the central part of India shows an unexpected increase (~+20%) in AOD. A simultaneous increase (decrease) in mid-tropospheric relative humidity (wind speed (WS) at 850 hPa) by +85 ± 6.0% (–12 ± 3.9%) occurred during the lockdown. It is found that on a daily scale, the mean AOD is positively (negatively) correlated with mid-tropospheric RH (WS) with a statistically significant linear correlation coefficient of 0.53 (−0.43). An increase (decrease) in RH (WS) of 20% (1 m s–1) was observed to increase AOD by 0.10 (0.04). Thus, we hypothesize that during the lockdown, the increased AOD over central India was due to increased atmospheric moisture coupled with stagnant circulation condition.

Effect of increased cabin recirculation airflow fraction on relative humidity, CO2 and TVOC

In the CleanSky 2 ComAir study, subject tests were conducted in the Fraunhofer Flight Test Facility cabin mock-up. This mock-up consists of the front section of a former in-service A310 hosting up to 80 passengers. In 12 sessions the outdoor/recirculation airflow ratio was altered from today’s typically applied fractions to up to 88% recirculation fraction. This leads to increased relative humidity, carbon dioxide (CO2) and Total Volatile Organic Compounds (TVOC) levels in the cabin air, as the emissions by passengers become less diluted by outdoor, dry air. This paper describes the measured increase of relative humidity, CO2 and TVOC level in the cabin air for the different test conditions.

Correlations between 7Be, 210Pb, dust and PM10 concentrations in relation to meteorological conditions in northern Poland in 1998–2018

Analysis of a twenty-year (1998–2018) data series on 7Be concentrations in weekly collected aerosol samples in northern Poland showed a clear pattern of seasonal changes in 7Be with a maximum in the summer period associated with the most intensive thermal convection and vertical mixing. Activity concentrations of 7Be ranged from 480 μBq m−3 to 9370 μBq m−3. A strong relationship has been shown between 7Be concentrations observed in years and the activity of the Sun related to the sunspot number. Activity concentrations of 210Pb in aerosol ranged from 17 μBq m−3 to 1490 μBq m-3 with maximum occurring in the winter. The difference in the seasonal pattern in 7Be and 210Pb concentrations were directly related to the different sources of both isotopes, as an additional source of 210Pb was the products of combustion during the heating season. Similar pattern with maximum concentrations in winter was observed for PM10, as the main source is the same as in the case 210Pb. A content of PM10 was in the range from 6.5 to 81.7 μg m−3. A statistically significant correlation between both isotopes occurs. At the same time, 7Be, 210Pb and PM10 are visibly related to the dust concentrations ranged from 7.3 μg m−3 in winter to 134.8 μg m−3 in spring. Statistical analysis carried out with simple regression model, stepwise multiple regression, and Random Forest models showed that the sunspots number, air temperature and sunshine duration have the most substantial impact on transport, and hence the concentration of 7Be in the surface layer of the atmosphere. The increase in relative humidity and precipitation and higher wind speed have a statistically significant effect on the reduction of 7Be concentrations in surface air.

In-situ-desorption of indoor relevant VOC toluene and limonene on activated carbon based filter media using high relative humidity

The adsorptive purification of the gas phase is currently gaining more and more importance in the field of heating, ventilation and air conditioning (HVAC) because people spend most of the day in buildings. The so-called VOC (Volatile Organic Compounds) represent a health-relevant category of pollutant gases. To reduce the accumulation of VOC in buildings, adsorptive filters can be integrated into ventilation systems. For reasons of energy efficiency of ventilation systems (low pressure drop), filters with a pleated flat sheet filter media are often used. The special feature of that kind of filter media is that they have low material thicknesses and correspondingly contain small amounts of activated carbon. Their adsorption capacity and thus their service life are accordingly low compared to cartridges. In order to increase the service life of the described filters, the concept of in-situ desorption consisting of 12-h adsorption at 0.9 ppm, 23 °C and 50% relative humidity and a subsequent 12-h in-situ-desorption with challenge gas-free air and 50% and 90% RH (23 °C) is being investigated on two different activated carbon-based filter media. The substances used are the VOC toluene and d-limonene, which are relevant in indoor air. The more volatile toluene can be desorbed more efficiently than the less volatile limonene. An increase in relative humidity leads to an improvement in desorption, especially for toluene. Stationary cyclic operation is conceivable here. Furthermore, worse desorption is possible on the medium with the more microporous activated carbon than on the medium with the less microporous activated carbon.

Colorimetric monitoring of humidity by opal photonic hydrogel

The present study demonstrated a new fast colorimetric humidity sensor using the opal hydrogel composite (OHC). First, a highly monodisperse polystyrene (PS) latex was synthesized by soap-free emulsion polymerization and deposited on a glass substrate in order to form a three-dimensional opal photonic crystal. Then, the homogenous hydrogel precursor was infiltrated into the interstitial space of opal by capillary forces and underwent chemical polymerization to construct an embedded PS crystalline colloidal array within a poly (acrylamide-co-acrylic acid) hydrogel network. The scanning electron microscopic images confirmed the formation of opal structures. An interesting feature of the presented OHC sensor is that the sensor is transparent in a dry state and an increase in relative humidity (RH) leads to a colorful film. In addition, UV/Vis spectroscopy was performed within an RH range of 25–95%, indicating that reflection peak height gradually develops by RH increasing and the peak position shifts from 413 to 518 nm. Further, the sensor functions extremely rapidly and changes its color by increasing RH within a few seconds (less than 3 s) and becomes transparent again quickly as humidity represents a decrease. Based on the results, repeated humidity changes revealed that the sensor has an excellent reproducibility without any reduction in response time and sensitivity or a color change. Finally, it has good adhesion to the glass substrate which makes it a suitable RH sensor in different applications, along with the rapid response time, high sensitivity, repeatability, and the visual alarm.

Characterization of black carbon aerosol at the summit of Mount Tai (1534 m) in central east China: Temporal variation, source appointment and transport

As a crucial absorption component of aerosols, black carbon (BC) plays a key role in modifying aerosol-planetary boundary layer (PBL) meteorology and hence aggravating haze pollution. With an altitude of 1534 m, Mt. Tai is close to the top of the PBL and located within the transportation channel from the North China Plain (NCP) to the Yangtze River Delta (YRD). In this study, BC aerosols were continuously observed using a seven-channel aethalometer (AE-33) at the summit of Mt. Tai from May 11 to June 25, 2017. The temporal variation, source and transport characteristics of BC in the upper PBL of central and eastern China in summer were then discussed. The average concentrations of BC, BCliquid and BCsolid were 1722.6, 1194.6 and 545.8 ng m−3, respectively, during the observation period. Liquid fuel sources were calculated and accounted for 64.7% of the BC mass concentration. The distributions of BC were mostly centralized in concentrations less than 600 ng m−3 (accounting for 21.9% of the total BC samples) and ranged from 1400 to 2200 ng m−3 (32.5%). Meteorological elements were determined to have great impacts on the distribution of BC concentrations, which increased with the decrease in visibility and wind speed and the increase in relative humidity (RH). The diurnal variations in BC presented high values during the daytime and low values during the nighttime, with peaks at 06:00, 11:00 and 18:00. Long-range transport from the YRD regions in summer, as well as the surrounding regions, played an important role in determining the BC concentrations at Mt. Tai with concentration weighted trajectory (CWT) values exceeding 2000 ng m−3. Air masses may move northward to the NCP after passing through Mt. Tai, and they contributed more than 1800 ng m−3 to the BC in the whole NCP region.

Investigation on non-equilibrium phase transition in wave rotor

Wave rotor refrigeration is a new method of expansion refrigeration. Non-equilibrium phase transition is one of the key factors that influence the refrigeration performance of wave rotor. Since the process of phase transition is transient and high-frequency, there are challenges in related researches. At first, this paper traces the movement trajectory of small particles in wave rotor and confirms the existence of evaporation in wave rotor. Based on this, the numerical analysis model of wave rotor that takes into account the phase transition regarding evaporation as reverse process of condensation is built up. On this basis, the change of droplet radius, droplet number and liquefaction fraction in wave rotor is obtained. Besides, the influence of inlet pressure and humidity on refrigeration performance of wave rotor is found out. The results show that with the increase of pressure of HP inlet, the isentropic expansion efficiency increases and the increase becomes gentle. With the increase of relative humidity of HP inlet, the efficiency decreases and the decrease reaches 2.8% at maximum. The results can help optimize wave rotor performance and be used for reference to wet gas transient temperature change.

Hygroscopic proprieties of fig (Ficus carica L.): Mathematical modelling of moisture sorption isotherms and isosteric heat kinetics

Moisture sorption isotherms of two fig varieties most grown in Moroccan orchards were assessed simulating the conditions of storage using the gravimetric static method at 30, 40, and 50°C. The equilibrium was reached within 8 to 10 days for desorption and adsorption, respectively over a stepwise increase of relative humidity ranging from 5% to 90%. Experimental data of fig sorption were fitted to three of most used models: GAB, Enderby and Peleg. High-accuracy prediction of the sorption isotherms for “Sarilop” and “Kadota” was obtained with Enderby and Peleg, respectively, since they presented the best adjustment (generally, R² ≥ 0.997 and SE ≤ 1.85). Thermodynamic proprieties revealed a remarkable varietal effect regarding the net isosteric heat, the differential entropy. These differences were probably attributed to chemical composition, structure of the tissues and the intermolecular forces between the sorption sites, water vapor, chemical composition, structure of the tissues and the intermolecular forces. The net isosteric heat of fig samples sorption decreases as the moisture content increased, and was found to be a polynomial function of moisture content for adsorption and desorption. The hysteresis loop was observed among all experiments and its magnitude was remarkable in water activity range of 0.4–0.8. The applied enthalpy-entropy compensation theory to sorption isotherms and plots net isosteric of sorption versus differential entropy provided the isokinetic temperatures, which suggested an enthalpy-controlled sorption process. As a first study of fig thermodynamic proprieties in Morocco, this work aimed to contribute to the fig drying and packaging design and optimization. It also intends to predict moisture changes that might occur during heating process and determine energy requirement for fig drying and shelf life stability.