Relative Humidity Distribution Research Articles

The Evolving Distribution of Relative Humidity Conditional Upon Daily Maximum Temperature in a Warming Climate

AbstractThe impacts of heat waves in a warming climate depend not only on changing temperatures but also on changing humidity. Using 35 simulations from the Community Earth System Model Large Ensemble (CESM LENS), we investigate the long‐term evolution of the joint distribution of summer relative humidity (RH) and daily maximum temperature (Tmax) near four U.S. cities (New York City, Chicago, Phoenix, and New Orleans) under the high‐emissions Representative Concentration Pathway (RCP) 8.5. We estimate the conditional quantiles of RH given Tmax with quantile regression models, using functions of temperature for each city in July for three time periods (1990–2005, 2026–2035, and 2071–2080). Quality‐of‐fit diagnostics indicate that these models accurately estimate conditional quantiles for each city. As expected, each quantile of Tmax increases from 1990–2005 to 2071–2080, while mean RH decreases modestly. Conditional upon a fixed quantile of Tmax, the median and high quantiles of RH decrease, while those of the Heat Index (HI) and dew point both increase. This result suggests that, despite a modest decrease in median relative humidity, heat stress measured by metrics considering both humidity and temperature in a warming climate will increase faster than that measured by temperatures alone would indicate. For a fixed Tmax, the high quantiles of RH (and thus of HI and dew point) increase from 1990–2005 to 2071–2080 in all four cities. This result suggests that the heat stress of a day at a given Tmax will increase in a warming climate due to the increase of RH.

3D Numerical Analysis of the Natural Ventilation Behavior in a Colombian Greenhouse Established in Warm Climate Conditions

Global food production and availability in hot climate zones are limited by biotic and abiotic factors that affect agricultural production. One of the alternatives for intensifying agriculture and improving food security in these regions is the use of naturally ventilated greenhouses, an alternative that still requires information that allows technical criteria to be established for decision-making. Therefore, the objective of this work was to study the spatial distribution of temperature and relative humidity inside a greenhouse built in the Colombian Caribbean. The methodological approach included the implementation of an experimentally validated 3D numerical simulation model. The main results obtained allowed to determine that the airflows generated inside the greenhouse had average velocities below 0.5 m/s and were mainly driven by the thermal effect of natural ventilation. It was also found that the gradients generated between the interior of the structure and the exterior environment presented values lower than 2.0 °C for temperature and −6.3% for relative humidity. These values can be considered low in comparison with other structures evaluated in other regions of the world where the gradients can reach values higher than 10 °C and 13% for temperature and relative humidity, respectively.

An Optimization Model for Environmental Ergonomics Assessment in Bioproduction of Food SMEs

Environmental ergonomics in bioproduction of food Small Medium-sized Enterprises (SMEs) become a concern and need to be optimized. An optimization model was developed using a Genetic Algorithm (GA). The weight of an Artificial Neural Network Model was used as a fitness function for GA. The research objectives were: 1) To design an environmental ergonomic assessment system for bioproduction of Food SMEs, 2) To develop an optimization model for environmental ergonomic assessment using a Genetic Algorithm. GA is utilized to search optimal set points of environmental ergonomics based on the predicted fitness values. Each chromosome of GA represents the environmental ergonomics value. The parameters were heart rate, bioproduction temperature, distribution of bioproduction relative humidity and light intensity. The target of the optimization model was the bioproduction temperature set points. The research result indicated the model generated optimum values of environmental ergonomics parameter in bioproduction of food SMEs. The parameters could be used to provide standard workplace environment for the sustainability of food SMEs.

Experimental analysis of the air humidification process for humid air turbine cycle using a two-phase measurement system

The humid air turbine (HAT) cycle utilizes the low-temperature heat from the gas turbine exhaust to humidify the air, thereby increasing the specific output work. The air humidification process has a significant impact on gas turbine efficiency. So far, there is still a lack of reliable experimental data from gas-liquid two-phase flow, which limits the in-depth study of the air humidification process. In this work, the new multi-point gas–liquid two-phase temperature and relative humidity measurement system suitable for countercurrent pressurized humidifier is re-designed, the temperature and relative humidity distributions of humid air and the water temperature distribution are obtained along the height of humidifier. The effects of the water–air ratio and inlet water temperature on the humidification process are thoroughly investigated. The water–air ratio has little effect on the outlet air temperature, and it has a significant effect on the air and water temperature in the packing segment, and the relative humidity and absolute humidity increase as the water–air ratio increases. The outlet air temperature and water temperature increase as the inlet water temperature improves. The sooner the air reaches saturation and the absolute humidity increases more significantly at higher inlet water temperature. Vapor condensation occurs at the interface during the humidification process. Besides, the outlet water temperature can be cooled to be lower than the wet bulb temperature of the inlet air, but always higher than the dew point temperature of the inlet air. The measurement data provide an experimental basis for studying the heat and mass transfer inside the humidifier.

Ensemble-based deep learning for estimating PM2.5 over California with multisource big data including wildfire smoke

IntroductionEstimating PM2.5 concentrations and their prediction uncertainties at a high spatiotemporal resolution is important for air pollution health effect studies. This is particularly challenging for California, which has high variability in natural (e.g, wildfires, dust) and anthropogenic emissions, meteorology, topography (e.g. desert surfaces, mountains, snow cover) and land use. MethodsUsing ensemble-based deep learning with big data fused from multiple sources we developed a PM2.5 prediction model with uncertainty estimates at a high spatial (1 km × 1 km) and temporal (weekly) resolution for a 10-year time span (2008–2017). We leveraged autoencoder-based full residual deep networks to model complex nonlinear interrelationships among PM2.5 emission, transport and dispersion factors and other influential features. These included remote sensing data (MAIAC aerosol optical depth (AOD), normalized difference vegetation index, impervious surface), MERRA-2 GMI Replay Simulation (M2GMI) output, wildfire smoke plume dispersion, meteorology, land cover, traffic, elevation, and spatiotemporal trends (geo-coordinates, temporal basis functions, time index). As one of the primary predictors of interest with substantial missing data in California related to bright surfaces, cloud cover and other known interferences, missing MAIAC AOD observations were imputed and adjusted for relative humidity and vertical distribution. Wildfire smoke contribution to PM2.5 was also calculated through HYSPLIT dispersion modeling of smoke emissions derived from MODIS fire radiative power using the Fire Energetics and Emissions Research version 1.0 model. ResultsEnsemble deep learning to predict PM2.5 achieved an overall mean training RMSE of 1.54 μg/m3 (R2: 0.94) and test RMSE of 2.29 μg/m3 (R2: 0.87). The top predictors included M2GMI carbon monoxide mixing ratio in the bottom layer, temporal basis functions, spatial location, air temperature, MAIAC AOD, and PM2.5 sea salt mass concentration. In an independent test using three long-term AQS sites and one short-term non-AQS site, our model achieved a high correlation (>0.8) and a low RMSE (<3 μg/m3). Statewide predictions indicated that our model can capture the spatial distribution and temporal peaks in wildfire-related PM2.5. The coefficient of variation indicated highest uncertainty over deciduous and mixed forests and open water land covers. ConclusionOur method can be generalized to other regions, including those having a mix of major urban areas, deserts, intensive smoke events, snow cover and complex terrains, where PM2.5 has previously been challenging to predict. Prediction uncertainty estimates can also inform further model development and measurement error evaluations in exposure and health studies.

Degradation prediction of encapsulant-glass adhesion in the photovoltaic module under outdoor and accelerated exposures

Maintaining good encapsulant-glass adhesion is important to ensure the long-term durability of photovoltaic (PV) modules. An exposure dose based model was used in this study to predict the temporal and spatial degradation of encapsulant-glass adhesion inside the PV module under hygrothermal exposure. The exposure dose is a single parameter that combines the exposure temperature, humidity and time using an exponential relation that is governed by a degradation activation energy. Peel tests were used to measure degradation in ethylene–vinyl acetate (EVA)-glass adhesion in PV module laminates that are aged under various constant temperature and humidity environments. An optimization technique applied to fit an exponential relation between the degraded adhesion strength and exposure dose gave the degradation activation energy as 59.4 kJ/mol.The model was used to study EVA-glass adhesion degradation for glass-glass and glass-backsheet based PV modules exposed to 5 year outdoor (Delhi, India), damp heat, humidity freeze and thermal cycling environments. The spatial and temporal distribution of relative humidity at the EVA-glass interface inside the PV module was predicted considering Fickian diffusion in the backsheet and EVA. The predicted humidity is used to estimate the exposure dose, which is further used to predict adhesion degradation. The highest degradation in all exposures occurs at the edge for the glass-glass module, whereas near the gap between cells for the glass-backsheet module. The integrity of the interface near the exposed boundary can be assessed by the damp heat exposure, but the integrity away from the boundary cannot be assessed by the accelerated exposures.

Uncoupling Characteristics of Temperature and Relative Humidity Distribution in a Commercial-Size Polymer Electrolyte Membrane Fuel Cell

AbstractThe microenvironment of the electrodes in a polymer electrolyte membrane fuel cell (PEMFC) is critical to its performance and is significantly affected by the distribution of water and heat...

Modeling of the transport, hygroscopic growth, and deposition of multi-component droplets in a simplified airway with realistic thermal boundary conditions

Accurate predictions of the droplet transport, evolution, and deposition in human airways are critical for the quantitative analysis of the health risks due to the exposure to the airborne pollutant or virus transmission. The droplet/particle-vapor interaction, i.e., the evaporation or condensation of the multi-component droplet/particle, is one of the key mechanisms that need to be precisely modeled. Using a validated computational model, the transport, evaporation, hygroscopic growth, and deposition of multi-component droplets were simulated in a simplified airway geometry. A mucus-tissue layer is explicitly modeled in the airway geometry to describe mucus evaporation and heat transfer. Pulmonary flow and aerosol dynamics patterns associated with different inhalation flow rates are visualized and compared. Investigated variables include temperature distributions, relative humidity (RH) distributions, deposition efficiencies, droplet/particle distributions, and droplet growth ratio distributions. Numerical results indicate that the droplet/particle-vapor interaction and the heat and mass transfer of the mucus-tissue layer must be considered in the computational lung aerosol dynamics study, since they can significantly influence the precise predictions of the aerosol transport and deposition. Furthermore, the modeling framework in this study is ready to be expanded to predict transport dynamics of cough/sneeze droplets starting from their generation and transmission in the indoor environment to the deposition in the human respiratory system.

Climatology of Tropospheric Relative Humidity over the Korean Peninsula from Radiosonde and ECMWF Reanalysis

Conventional radiosondes can be used to measure the relative humidity over liquid (RHL) by assuming a saturated vapor pressure over the liquid. However, this assumption results in significant errors with respect to measurements in the upper troposphere, where the effect of ice is dominant. Therefore, this study presents a novel method that considers the effects of ice to determine the relative humidity from radiosonde RHL data for the last 40 years (1979–2018) over the upper layers of the Korean peninsula. Even though the relative humidity obtained from the reanalysis data was significantly different from the radiosonde-based RHL, the difference was much reduced when relative humidity was calculated using the novel method proposed in this study. Such improvements in the estimated relative humidity could be attributed to the consideration of the ice effect at temperatures above freezing level. Additionally, the validity of the relative humidity estimated in this study was established based on a two-week case analysis of data from Boseong station. Furthermore, two peak relative humidity modes for the lower and upper layers were clearly identified in the mean climatology profiles, which indirectly suggested the absence of mid-level clouds around the 700-hPa level and 500-hPa level in winter and summer, respectively. This study is meaningful as it is the first study to determine the relative humidity distribution over the Korean peninsula using radiosonde observations. The scientific value obtained can potentially be expanded by applying the proposed method to other radiosonde observation networks, which are widely distributed worldwide.

Experimental study on dynamic thermal environment of passenger compartment based on thermal evaluation indexes.

In this article, the thermal environment and the human thermal comfort of car cabin under different driving states in summer were studied experimentally. The weighted predictive mean vote model and the weighted equivalent temperature model were used for calculation and compared with the experimental values. The experimental results show that the air temperature and relative humidity distribution in cabin are affected by the space position and driving state. The temperature of the cabin seat, which is affected by solar radiation and crew, in the heating stage is slightly higher than the air temperature, while the cooling rate in the cooling stage is much lower than the air temperature. The predictive mean vote model and the equivalent temperature model are basically consistent with the actual thermal comfort of human body under the idle and driving conditions with the change of time. The prediction accuracy of the two models under the idle condition is higher than that under the driving condition, and the overall prediction accuracy of the equivalent temperature model is higher than that of the predictive mean vote model.

Moisture behavior of external insulated precast concrete wall panels

Excess moisture in concrete structures is a major problem in building industry. It is claimed that degradation of the finishing materials of concrete slabs is the largest source of volatile organic compound in the building stock in the Nordic countries. Considering concrete wall panels, the choice of the insulation material influences concrete drying considerably and causes a risk for moisture accumulation on the interior surface, if vapor tight finishing materials are used or if finishing materials are installed prematurely. Mineral wool insulation, which has predominately been used in Finland, is a vapor open material. However, vapor tight plastic foam insulation materials are nowadays more commonplace. Here we show that the overall rate of drying of the concrete panel with a vapor open insulation material is higher in comparison to the concrete panel with vapor tight insulation materials. However, relative humidity distribution near the inner surface of the concrete panel at the end of the drying phase is almost identical irrespective of the insulation material and the water vapor resistance of the interior surface material has a greater impact on the relative humidity level on the inner concrete surface. Moisture behavior of concrete panel walls is studied under a certain building schedule in Finnish environment and building conditions by numerical simulation. The model for drying of concrete is calibrated based on laboratory measurements. According to our study, self-desiccation and changing diffusivity due to the hydration process of the concrete cannot be ignored when evaluating the moisture behavior of the concrete wall panel structure with a low water binder ratio ( w/ b &lt; 0.5). Measurements indicate that the early age humidity drop is by up to 10 percentage points.

A coupled hygro-thermo-mechanical model for the evolution of saturation in early-age concrete

Shrinkage can cause deformation of concrete and unexpected cracking in concrete structures under normal serviceable conditions, particularly at early age. The evolution of relative humidity and saturation in concrete at early age is the main reason for the shrinkage of concrete. In order to analyze the shrinkage and development of relative humidity for concrete at early age, a hygro-thermo-mechanical model based on hybrid mixture theory (HMT) is established by taking into consideration the evolution characteristics of saturation. Based on the Rayleigh-Ritz distribution function and Laplace equation, along with the saturation evolution characteristics, a two-stage relative humidity calculation model for early-age concrete is established. The model is verified using the experimental results from the literature. It is found that the hygro-thermo-mechanical coupling model accurately predicts the evolution of temperature, relative humidity, and deformation of concrete at early age. The modified saturation model better reflects the evolution of relative humidity and saturation in concrete at early age compared with others. Additionally, development and distribution of temperature, relative humidity and saturation in early-age concrete are discussed. The research provides a theoretical basis for the study of the deformation of and cracking in early-age concrete.

Numerical analysis of air-cooled proton exchange membrane fuel cells with various cathode flow channels

Air-cooled proton exchange membrane (PEM) fuel cells simplify fuel cell design by combining oxygen supply and air cooling in open cathode channels. Their performance is sensitive to the structure of cathode channels, which significantly affects distribution of temperature, relative humidity and mass transfer in the cells. This study offers a three-dimensional air-cooled fuel cell model with consideration of electrochemistry simulation to investigate the effect of cathode channel design. Experiments are conducted to validate the model. It is observed that obvious gradient in the distributions of temperature, humidity and oxygen concentration lies in the membrane exchange assembly (MEA) between the channel and rib owing to air dual functions in distributing oxygen and cooling the stack. For models with fixed rib-channel ratio of 1.0, the performance is better when channel width is smaller. Considering the effect of contact resistance when the ratio is small, rib-channel ratio within a reasonable range of around 3.0 is preferred in order to enhance the performance. Channels with curved features improve the mass transfer from channel to catalyst layer, thus increasing the cell performance. This study is helpful for enhancing our understanding of the relationship between cell performance and cathode channel design in the air-cooled fuel cell.

Distribution of temperature, moisture and organic acids in storage facilities with heritage collections

The preservation of heritage collections in storage largely depends on the air quality conditions. Uncontrolled airflow transports unconditioned air into the building. Lowering the air exchange rate in unoccupied storage facilities is therefore essential to ensure acceptable climate conditions for the preservation of collections, while at the same time reducing the energy use for climate control. The concern is, however, that a restricted airflow can create uneven microclimates within a room, with thermal stratification as well as accumulation of indoor generated pollutants, which may accelerate the deterioration of the collections. This paper examines the air distribution within one storage building with a heating, ventilation and air-conditioning (HVAC) system, and in two rooms in another storage with semi-passive climate control. A sensor grid was established in each room in order to map the distribution of temperature, relative humidity (RH) and volatile organic acids determined as the sum of acetic and formic acid concentration. This study demonstrated that both tested ventilation forms upheld an acceptable climate performance with appropriate temperature and moisture distributions and without air pockets producing problematic microclimates. However, organic acids accumulated in concentrations up to 134 μg m−3 in parts of one storage room with semi-passive climate control. Whether to install a HVAC system with gaseous air filtration to remove organic acids will ultimately depend on the threshold level that caretakers are willing to accept.

Numerical and experimental investigation of the hygrothermal properties of corn stalk and magnesium phosphate cement (MPC) based bio-composites

This study includes the experimental and numerical investigation of the hygrothermal properties of magnesium phosphate cement (MPC) and corn stalk (CS) based bio-composites. Bio-composites were formulated using large size and small size corn stalk aggregates. Corresponding numerical models were established to investigate the effect of corn stalk aggregate on the hygrothermal properties of bio-composites. The validity of the numerical models was confirmed by comparing the experimental and numerical results. Hygrothermal properties of bio-composites were predicted through the heat and moisture transfer models. It was observed that numerical results showed satisfactory and close results with the experimental values. Finally, by using the proposed model, the effects of aggregates with different shapes and different volume fractions on heat and moisture transfer were studied. Results showed that the presented model is promising, and it can well evaluate the aggregates effect. The numerical results also showed that the aggregates effect can significantly affect the heat and moisture transfer. At the same time, the temperature effect cannot be ignored when predicting the heat and moisture transfer of the material. With increasing temperature, the aggregate effect will be relatively weakened. Meanwhile, based on this numerical model, the effect of temperature on sorption isotherm and relative humidity distributions in the bio-composites can be well predicted.

The evaluation and optimization of calibration methods for low-cost particulate matter sensors: Inter-comparison between fixed and mobile methods.

With the development of the air pollution control, the low-cost sensors are widely used in air quality monitoring, while the data quality of these sensors is always the most concern for users. In this study, data from nine air monitoring stations with standard PM instruments were used as reference and compared with the data of mobile and fixed PM sensors in Jinan, the capital city of Shandong Province, China. Data quality of PM sensors was checked by the cross-comparison among standard method, fixed and mobile sensors. And the impacts of relative humidity and size distribution (PM2.5/PM10) on the performance of PM sensors were evaluated as well. To optimize the calibration method for both fixed and mobile PM sensors, a two-step model was designed, in which the RH and PM2.5/PM10 ratio were both used as input parameters. We firstly calibrated the sensors with five independent models, and then all the calibrated data were linearly fitted by the LR-final model. In comparison with standard instruments, the LR-final model increased the R2 values of the PM2.5 and PM10 measured by fixed sensors from 0.89 and 0.79 to 0.98 and 0.97, respectively. The R2 values of PM2.5 and PM10 measured by the mobile sensors both increased to 0.99 from 0.79 and 0.62. Overall, the two-step calibration model appeared to be a promising approach to solve the poor performance of low-cost sensors.

Vertical water transport model in concrete based on the coupled effects of the capillarity, gravity and evaporation

A novel vertical water transport model in consideration of the capillarity, gravity effect and evaporation was proposed, and the corresponding finite difference method was recommended to determine the moisture distribution in concrete. The amounts of water absorption and water loss of concrete surface with time were measured, and the distributions of relative humidity (RH) and temperature in concrete were also tested under different environment conditions. Moreover, the numerical simulation was used to elucidate the phenomena of rot, damp and saltpetering in the dry-wet region of concrete column contacting with soil or water. The results showed that the variations of RH and temperature in concrete along the vertical height from liquid level accord well with a Bolztmann function. The relationship between the water absorption and time expresses as an exponential function, but it is a Logistic function between water loss and time. The moisture distribution in concrete observably changes with the vertical height from liquid level and distance from concrete surface, which is mainly caused by the dynamic equilibrium between the absorbed water by capillarity and gravity, and the evaporated water by evaporation. The significant change region of RH along the vertical height of concrete surface was closely related with concrete strength grade and external environment’s RH, and the corresponding values for C20, C30 and C40 are about 20 cm∼30 cm and 10 cm∼20 cm, respectively. The RH and temperature of concrete surface differ from that of external environment, which changes the traditional lopsided view considering the external environment as the micro environment in concrete. The pore characteristic for different concrete strength grade results in a significant variation of the moisture distribution in concrete, which expresses as the similar change trend but different value.

Modelling Indoor Environmental Conditions in a Commercial Broiler House

Turkey’s poultry industry has experienced significant growth in recent years, resulting in the construction of many new production facilities. It is important to maintain optimum environmental conditions for a profitable production. In this study, temperature, relative humidity and air velocity distribution inside a broiler house were analysed. Computational Fluid Dynamics (CFD) simulations (numerical method) and direct measurements (experimental method) were used to determine the appropriate indoor environmental conditions. Simulated values were validated by comparison with the measured values using the normalised mean square error (NMSE). The measured and predicted parameters of temperature, relative humidity and air velocity at birds’ height, human height, and roof height upon comparison gave average NMSE values of 0.139, 0.181 and 0.090, respectively. The results showed a good agreement between simulated and measured values as obtained NMSE values were less than 0.25. In conclusion, CFD simulation can be used as an alternative method for the analysis of poultry house indoor environment. A better understanding of indoor environment conditions in poultry house provides useful information for manufacturers and end users for better management decisions.

Spatial distribution of air temperature and relative humidity in the greenhouse as affected by external shading in arid climates

The effect of external roof shading on the spatial distribution of air temperature and relative humidity in a greenhouse (Tin and RHin) was evaluated under the arid climatic conditions of Riyadh City, Saudi Arabia. Two identical, evaporatively-cooled, single-span greenhouses were used in the experiment. One greenhouse was externally shaded (Gs) using a movable black plastic net (30% transmissivity), and the other greenhouse was kept without shading (Gc). Strawberry plants were cultivated in both greenhouses. The results showed that the spatial distribution of the Tin and RHin was significantly affected by the outside solar radiation and evaporative cooling operation. The regression analysis showed that when the outside solar radiation intensity increased from 200 to 800 W m–2, the Tin increased by 4.5°C in the Gc and 2°C in the Gs, while the RHin decreased by 15% in the Gc and 5% in the Gs, respectively. Compared with those in the Gc, more uniformity in the spatial distribution of the Tin and RHin was observed in the Gs. The difference between the maximum and minimum Tin of 6.4°C and the RHin of 10% was lower in the Gs than those in the Gc during the early morning. Around 2°C difference in the Tin was shown between the area closed to the exhausted fans and the area closed to the cooling pad with the external shading. In an evaporatively-cooled greenhouse in arid regions, the variation of the Tin and RHin in the vertical direction and along the sidewalls was much higher than that in the horizontal direction. The average variation of the Tin and RHin in the vertical direction was 5.2°C and 10% in the Gc and 5.5°C and 13% in the Gs, respectively. The external shading improved the spatial distribution of the Tin and RHin and improved the cooling efficiency of the evaporative cooling system by 12%, since the transmitted solar radiation and accumulated thermal energy in the greenhouse were significantly reduced.

Hygrothermal performance of ventilated prefabricated sandwich wall panel from recycled construction and demolition waste – A case study

Construction and demolition waste has been used for production of recycled aggregate concrete (RAC) with high replacement ratio (50%) of natural coarse aggregate. Upscaling RAC from material laboratory testing to new product implementation – ventilated prefabricated sandwich wall panel, which at the same time tackles the problem of natural resources conservation and extensive energy consumption in buildings, requires a proof-of-concept. This paper presents an experimental investigation of dynamic hygrothermal performance of developed building envelope system under real outdoor climate conditions and with real occupants living in the house for a one-year period in 2017/2018. Temperature and relative humidity distributions through all characteristic layers of panel showed that the positive effect of air ventilation on hygric (no highly moist conditions) and thermal (damping and time shifting of peak temperatures) performance was most pronounced for south panel adjacent to conditioned living room, while the less pronounced effect was for north panel subjected to unconditioned staircase. Furthermore, transient hygrothermal simulations using measured boundary and initial conditions showed that ventilated RAC wall panel has significantly outperformed both wall panel with closed air cavity and wall with applied ETICS system during summer, which indicates that naturally ventilated air has positive effect on wall's thermal performance in summer period. Additional simulations according to new EN ISO 52016-1:2017 Standard confirmed that high thermal mass of ventilated RAC wall panel has significant influence on dynamic building energy performance. For intermittent occupancy, it is beneficial when cooling energy is observed, while contrary to that it can require more heating energy compared to building with no heat storage capacity. However, when switching to continuous operating mode, high thermal mass of building envelope is beneficial from both of these energy aspects. This pattern has been confirmed in two different Croatian climates – continental and littoral.