Humidity Distribution Research Articles

Understanding Controlling Factors of Extratropical Humidity and Clouds with an Idealized General Circulation Model

Abstract This paper examines the physical controls of extratropical humidity and clouds by isolating the effects of cloud physics factors in an idealized model. The Held–Suarez dynamical core is used with the addition of passive water vapor and cloud tracers, allowing cloud processes to be explored cleanly. Separate saturation adjustment and full cloud scheme controls are used to consider the strength of advection–condensation theory. Three sets of perturbations to the cloud scheme are designed to test the model’s sensitivity to the physics of condensation, sedimentation, and precipitation formation. The condensation and sedimentation perturbations isolate two key differences between the control cases. First, the sub-grid-scale relative humidity distribution assumed for the cloud macrophysics influences the location and magnitude of the extratropical cloud maxima, which interrupt the isentropic transport of moisture to the polar troposphere. Second, within the model’s explicit treatment of cloud microphysics, re-evaporation of hydrometeors moistens and increases clouds in the lower troposphere. In contrast, microphysical processes of precipitation formation (specifically, the ratio of accretion to autoconversion) have negligible effects on humidity, cloudiness, and precipitation apart from the strength of the large-scale condensation and formation cycle. In addition, counterintuitive relationships—such as cloud condensate and cloud fraction responding in opposing directions—emphasize the need for careful dissection of physical mechanisms. In keeping with advection–condensation theory, circulation sets the patterns of humidity, clouds, and precipitation to first order, with factors explored herein providing secondary controls. The results substantiate the utility of such idealized modeling and highlight key cloud processes to constrain.

Numerical evaluation of indoor hygrothermal behavior with heat and moisture transfer in walls by analytical conditions

Studies analyzing indoor thermal environments according to variables such as the outdoor climate, wall layer, and building composition have benn conducted using building simulations. However, previous analyses of hygrothermal performance considering moisture are insufficient. Therefore, this study propose a process for evaluating indoor hygrothermal performance according to parameters using two different simulations. First, heat and moisture transfer in walls (external and internal walls, roofs, and floors) was analyzed, and the hygrothermal performance of the indoor environment was investigated based on the hygrothermal behavior of walls. The heat and moisture transfer analysis showed that the relative humidity (RH) and water content were high inside the wall (E) and floor layers owing to regional climatic conditions. The results of the indoor environment simulation indicated a distinct distribution of temperature and humidity, owing to the heat and moisture fluxes from the inner surfaces. In addition, as a result of improving the hygrothermal performance by changing the building materials for exterior walls, the heat flux decreased by 30%, and the moisture flux decreased by 58%. These results confirmed that the boundary conditions for temperature and humidity required to evaluate indoor hygrothermal environments can be analyzed according to climatic conditions and wall layer compositions.

What does Modelling Tells us on the Influence of Certain Weather Parameters on Oil Palm Production in Peninsular Malaysia

Background: Oil palm has been recognized as one of the most important crops especially in Southeast Asia and the rest of the world. Palm oil production has recently been lowered as a result of the influence of various factors, which include weather and climate. The distribution of temperature, wind speed, relative humidity, solar radiation and rainfall all influence the growth and development of palms, which later reflects in the production quantity of the fresh fruit bunches and palm oil. The objective of this study is to investigate the impacts of various weather factors especially (temperature, wind speed, relative humidity, solar radiation and rainfall) on oil palm production in Peninsular Malaysia. Methods: The Statistical Package for Social Sciences (SPSS) 20.0 version was used to analyse the data, which include descriptive statistics and multilinear regression (MLR). The MLR model evaluated the strength of the relationship between oil palm yield (as a dependent variable) and temperature, solar radiation, wind speed, relative humidity and precipitation. Temperature, wind speed, relative humidity, solar radiation and rainfall, on the other hand, have been shown to have little effect on oil palm production and yield. Result: According to the R2 value, the independent variables only explained 20.2% of the variation in palm oil production. This study recommends operating within a comprehensive framework that includes scientific research, planting improved varieties, enhancing regional intellectual and academic leadership, engaging the participation of private and public stakeholders, highlighting participatory initiatives with researchers in consumer countries and enhancing growers’ ability to adapt best agroecological practises.

Characteristics and Distribution of Some Radiation Parameters over Nigeria

This study examined the distribution and characteristics of Surface Solar Radiation Downward (SSRD), sunshine duration, cloudiness index, relative humidity, temperature, and wind speed from the archive of the NASA Power project between the years 2010 and 2020 over Nigeria using 37 stations. The datasets were subjected to monthly and seasonal analysis over three climatic zones in Nigeria. The results show that the SSRD of the Sahel is generally higher than that of the Savannah and Guinea Coast. Sunshine duration was found to increase seasonally and from south to north. From the extreme edge of the coastal region in the southern part of Nigeria to its far northern region, the mean sunshine duration hour increases northward from about 2075 hours over the coastal region of the south to about 3525 hours in the north. Relative humidity fluctuates between 70-90%, which peaks in August and declined back to its minimum (70%) in December. Observed over all seasons, relative humidity decreases northward from the far south near the Atlantic Ocean to the far north of Nigeria. This is in opposition to the pattern of 2m temperature observed, that is, the 2 m temperature spatial pattern increases from the south to the north. In terms of sky conditions classification, over Nigeria, the cloudiness index is generally less than 0.45. Over the Guinea Coast cloudiness index is observed to be higher than in Savannah and the Sahel zones in all the months with the lowest index of 0.42 in March and the highest index of 0.45 in September. However, the northeastern part of Nigeria is observed to be majorly cloudier in JJA and SON seasons than the far southern region of the country. However, wind speed is observed to be significantly lower than 2.7 m/s over the Guinea Coast compared to other zones. Relatively high and strong winds were noticed to be widespread over the extreme part of the northeastern and northwestern parts of Nigeria in all the seasons, making the region more suitable for wind energy generation.

CFD Study of a Tunnel-Ventilated Compost-Bedded Pack Barn Integrating an Evaporative Pad Cooling System.

Simple SummaryIt is known that improving the welfare of cows increases dairy productivity. A compost-bedded pack barn equipped with evaporative cooling pads to regulate the inside environmental conditions of dairy seems to be a synergic combination to improve substantial the welfare in dairy facilities. However, there is a lack of information about both techniques working together. A computational model of a tunnel-ventilated compost-bedded pack barn with an evaporative pad cooling system was developed to know the spatial distribution of temperature, relative humidity and velocity of the air inside the barn. These variables allowed us to compute a thermal stress index for dairy cattle to identify the geometric characteristics and operative conditions of the evaporative pad cooling that provide the best environmental conditions inside the barn according to the outside environmental conditions.Evaporative cooling is one of the most efficient techniques to reduce heat stress in cows in agricultural facilities. Additionally, compost-bedded pack barn has been shown to improve the welfare and production of cows. Two techniques were combined and analysed by developing a computational fluid dynamics (CFD) model of a tunnel-ventilated compost-bedded packed barn that integrated the heat and airflow dynamics of an evaporative pad cooling system. This allowed us to study the distribution of dry-bulb temperature, relative humidity and airflow velocity inside the barn based on the external environmental conditions, thickness of the pad, water temperature and specific manufacturer characteristics of the pad, providing optimal cooling pad location, size and operating conditions in the barn. Employing experimental data the CFD model was validated showing good agreement. The Equivalent Temperature Index for dairy Cattle (ETIC) was used to determine the level of stress of the cows considering the airflow velocity. It was found a moderate stress due to high relative humidity and low airflow velocity. From the predicted results, it was recommended to increase the airflow velocity above 3 m s when simultaneously the external dry-bulb temperature and relative humidity exceed 30 °C and 55%, respectively, simultaneously. Additionally, installation of baffles at the pad outlet to drive the airflow to the floor was suggested to improve the drying of the compost-bedded closed to the pads, where a low airflow velocity region was established.

Performance analysis of air curtains on indoor environment and dehumidification energy consumption in a low humidity plant

ABSTRACT The purpose of this study is to evaluate the effect of air curtains on indoor environment and dehumidification energy consumption for different air supply angle and velocity. The numerical investigation is conducted in a low-humidity plant located in the atmospheric boundary layer. The standard k-epsilon turbulence model is used in the simulation study. The optimum air supply angle and velocity are evaluated based on temperature and humidity distribution. The simulation cases range in air supply angle from 0° to 20° and velocity from 6 m/s to 14 m/s, which is studied by means of orthogonal experiments. Simulation results show that air curtain can reduce the average indoor temperature of the plant by up to 3.9°C and reduce the average moisture content by up to 86.6%. The energy saving assessment of the dehumidification rotor system shows a parabolic variation in energy consumption with increasing air velocity at a certain air supply angle. The optimum energy consumption occurs in the range of 9–11 m/s for air supply velocity. When air supply velocity is over 11 m/s, the airflow exchange is enhanced by air curtain at the plant opening, resulting in higher energy consumption from air leakage for dehumidification.

Non-Invasive Measurement of Humidity Distribution in Polymer Electrolyte Fuel Cells (PEFCs): Part I. In Situ Proof of Concept

A non-invasive method to determine the local relative humidity (RH) and local high frequency resistance (HFR) distribution from inlet to outlet of polymer electrolyte fuel cells (PEFCs) is presented. The method uses a plurality of electrodes attached to the outer flow field surface to inject alternating currents and measure the resulting voltage amplitudes at the flow fields’ surface. Since the measured voltage amplitudes, are highly dependent on the actual electrode positioning on the flow field boundaries, they are interpreted by interpolation between reference measurements at homogeneous relative humidity conditions and known overall cell impedance. The method is implemented experimentally using alternating current injections at a frequency of 1 kHz at well-defined asymmetric in situ N2/N2 conditions on a 200-cm2 cell in a 6-cell short-stack. The comparison between the RH distribution and the outlet RH sensor data yields a very good match. The same can be said when comparing the HFR distribution and the global cell HFR. Finally, the sensitivity of the method is tested by varying the mass flow rate with asymmetrical RH conditions. The results are highly reproducible in all the tested conditions.

Dynamic performance analyses and optimization studies on air dehumidifiers using multi-stage desiccant plates

• Dynamic air dehumidification processes of a desiccant plate (DP) were studied. • Three causes for the generation of ineffective sections are found. • For the dehumidifier with multi-stage DPs, recommended stage number is 2. • An advanced dehumidifier is proposed, ineffective DPs of which can be replaced. • Effective working period of the advanced dehumidifier is extended by 2.2%∼34.8%. In this study, a novel transient air dehumidifier that can meet the dehumidification demands at places without a constant energy supply and uses multi-stage desiccant plates was proposed. Based on the simulation methods, parametric and optimization studies were carried out to extend the effective working duration. First, the air handling processes, transient temperature and humidity distribution fields of a typical desiccant plate were investigated. The results indicated that there are three reasons for the generation of ineffective dehumidification sections. To reduce the proportion of the ineffective sections and to increase the effective working duration, parametric analyses were carried out on the desiccant plate, considering factors such as the initial water content ( W ini ), inlet air humidity ratio ( ω a,in ), and length of the desiccant plate. The results show that, if the required outlet humidity ratio ( ω ∗ ) is lower than 12–13 g/kg, W ini = 0.1 kg/kg is preferred for ω a,in between 15 and 19 g/kg. Subsequently, a dehumidifier with multi-stage desiccant plates (original dehumidifier) was designed, and the optimized stage number for different total thicknesses of desiccant plates was investigated to improve the dehumidification performance. When ω ∗ is 10 g/kg, the recommended stage number is two. Finally, an advanced dehumidifier is introduced in which an ineffective desiccant plate can be replaced with a new desiccant plate. For the advanced dehumidifier, the proportion of ineffective sections can be effectively reduced by 14.6%–93.2%, and the effective working duration can be extended by 2.2%–34.8%, compared to the original dehumidifier that has the same total thickness as the desiccant plates.

Regression Analysis Performed with Respect to the Velocity and Temperature

Abstract: Today vehicles are like our necessity in life. Most of the people of metro cities spend minimum 2-4 hour daily in their car. So people want better thermal comfort. Nowadays companies start focusing on customer choice. Vehicular cabin climate is adjusted by making changes in dry bulb temperature. It depends upon person that in which range person feels thermally comfort. This temperature range is always deviate from person to person. Every person has different metabolic rate so range of thermal comfort diverges person to person and it also depend upon clothing of people. If more powerful air-conditioner is applied then it affects the car performance means it lessen the average of vehicle. Air-conditioner will be applied in a limit. Thermal comfort is depending upon capacity of air conditioner, air velocity in car cabin, Air temperature, humidity and air flow distribution. So, first thing is capacity of air conditioner that will not be altered to higher value because AC is one and the only thing which consumes more power than other equipment. If large air conditioner is applied it will not be economical also. This is not the optimal solution for increasing thermal comfort. Air temperature can be decreased to improve thermal comfort but in this case size or capacity of air-conditioner will increase, ultimately this will increase cost. Last parameter is air flow distribution in which the pattern of air flow will be analyzed. In hatchback cars always there is a complaint of uneven cooling means cooling at front seat is good but very less cooling at back seat. Generally after an hour you feel some cooling at back. So there is need of optimal solution which is not too costly and also economic with respect to kilometer per liter. In this study of air pattern conclusion can be drawn that if there is any A.C. 2 vent will also present for back seat. Thermal comfort is also relying on Glass transmissivity of window glass in car cabin.

Heat and moisture transfer and dimension optimization of cross-flow hollow fiber membrane contactor for membrane distillation desalination

Membrane distillation desalination (MDD) is a promising desalination technology, which can be driven by renewable energy because of its mild operating temperature and pressure, and can obtain high purity distilled fresh water by realizing non-direct contact between process liquid and cold fluid. As the core component of MDD process to achieve vapor-liquid separation, the cross-flow hollow fiber membrane contactor strengthens the heat and moisture transfer efficiency of shell side by means of continuous disturbance of fiber bundle to the air flow compared with the parallel-flow membrane contactor. To reveal the coupled heat and moisture transport between hot brine and process air in the cross-flow hollow fiber membrane contactor, a two-dimensional mathematical model was established and verified by comparison of experimental results. By analyzing the effects of operating conditions and contactor dimensions on solution and air temperature and humidity distributions, contactor dimensions were optimized to facilitate the design and performance improvement of the membrane contactor. For sensible heat transfer, the effective transfer region is mainly concentrated in a limited long narrow air inlet region, which accounts for about 17% of the total area. Whereas for moisture transfer, the effective transfer region is the square region where the air inlet segment and the solution inlet segment overlap, which accounts for about 44% of the total area. To obtain superior membrane flux, long and narrow contactors should be selected for low solution temperature (Tsi < 71 °C), low air Reynolds number (Rea < 62) and high solution Reynolds number (Res > 58); otherwise, short and wide contactors should be selected. To improve the humidification efficiency, it is advisable to choose a short and wide contactor, and reducing the solution temperature and air flow rate and increasing the solution flow rate also help to improve the humidification efficiency.

3D numerical simulation of hot airflow in the human nasal cavity and trachea

Background and objectiveThe primary function of the human respiratory system is gas and moisture exchange, and conditioning inhaled air to prevent damage to the lungs and alveoli. In a fire incident, exposed soft tissues contract and the respiratory system may be severely damaged, possibly leading to respiratory failure and even respiratory arrest. The purpose of this study is to numerically simulate hot airflow in the human upper airway and trachea to investigate heat and moisture transfer and induced thermal injuries. MethodsFor analysis, the airflow is assumed to be laminar and steady, and simulations have been carried out at volume flow rates of 5 and 10 L/min, inlet temperatures of 70–240 °C, and relative humidity up to 40%. The mucous layer and surrounding tissues are incorporated into the conducting zone of the model. The blood perfusion is considered at different rates up to 5(Kg/m3.s) to regulate the temperature, and the vapor concentration is coupled with the energy equation. ResultsThe temperature and humidity distribution on the airway wall were calculated for all the studied conditions in order to find the mild and severe burn for different inhaled air temperatures. At the inlet temperatures of 70 and 100 °C, there are mild burns in several nasal cavity regions. At the higher temperatures of 160 and 200 °C, these areas suffer from severe burns and mild burns occur at the superior parts and nasopharynx. Rapid evaporation and tissue destruction will be observed if anyone breathes the 240 °C air. ConclusionsThe results show that the hot inlet temperatures drop below 44 °C when passing through the upper airway, and the lower airway was not affected. Increasing the inlet temperature from 70 to 240 °C extends the burns from mild to severe and the affected areas from the beginning of the nasal cavity to the pharynx.

Numerical simulation of evaporative cooling process in a medium-gap-medium arrangement

Wet medium is the key components of direct evaporative cooling system, and its performance affects the cooling performance extensively. The medium arrangement contributes much to good cooling performance of direct evaporative cooling system. The current paper continues previous experimental study of medium-gap-medium arrangement of wet medium, aiming to investigate the heat and mass transfer mechanism in such novel arrangement. A 3-D model was established using Fluent 18.0 to simulate the heat and mass transfer process in medium-gap-medium arrangement of wet medium. The airflow field, air temperature, humidity distribution and pressure drop were explored. The effects of the widths of the air gap, ambient dry-bulb temperature, wet-bulb temperature, and air speed on the cooling performance of medium-gap-medium arrangement were studied. Simulation based on the condition of air dry-bulb temperature of 27 °C, wet-bulb temperature of 19 °C, air speed of 1.5 m s−1, finds that: (1) the air temperature drops flowing through the 100 mm medium, 100 mm gap and 100 mm medium successively are 4.3 °C, 1.3 °C and 1.6 °C, respectively. The two 100 mm medium zones accounts for 82.5% cooling of the total cooling effect while the 100 mm gap zone accounts for 17.5% cooling as there exists water rain in the gap zone; (2) the pressure drops of the first 100 mm medium zone, the 100 mm gap zone and the second 100 mm medium zone are 7.97 Pa, 0.31 Pa and 7.93 Pa, respectively. (3) a decrease in the cooling efficiency over 11% can be attained when the air speed changes from 0.5 m s−1 to 3.0 m s−1.

Simultaneous measurement of near-water-film air temperature and humidity fields based on dual-wavelength digital holographic interferometry.

We present a method to reconstruct the near-water-film air temperature and humidity distributions synchronously by measuring the phase delays based on dual-wavelength digital holographic interferometry. A falling water film device was used to create a water film evaporation environment and generate axially uniform temperature and humidity fields. The relationship between air temperature, humidity and phase delay is derived from the Edlen equations. With such relationship, the temperature and humidity distributions can be solved directly according to phase delays of two different wavelengths. An edge phase enhancement method and an error elimination method with PSO are presented to improve the measurement accuracy. The temperature and humidity fields in the falling water film model were experimentally reconstructed with temperature deviation of 0.06% and relative humidity deviation of 2.61%.

Field Campaign Evaluation of Sensors Lufft GMX500 and MaxiMet WS100 in Peruvian Central Andes.

The research presents the inter-comparison of atmospheric variables measured by 9 automatic weather stations. This set of data was compared with the measurements of other weather stations in order to standardize the values that must be adjusted when taken to different areas. The data of a set of a total of 9 GMX500, which measures conventional meteorological variables, and 10 WS100 sensors, which measures precipitation parameters. The automatic stations were set up at the Huancayo Observatory (Geophysical Institute of Peru) for a period of 5 months. The data set of GMX500 were evaluated comparing with the average of the 9 sensors and the WS100 was compared with an optical disdrometer Parsivel. The temperature, pressure, relative humidity, wind speed, rainfall rate, and drop size distribution were evaluated. A pair of GMX500 sensors presented high data dispersion; it was found found that the errors came from a bad configuration; once this problem was solved, good agreement was archived, with low RMSE and high correlation. It was found that the WS100 sensors overestimate the precipitation with a percentage bias close to 100% and the differences increase with the greater intensity of rain. The drop size distribution retrieved by WS100 have unrealistic behavior with higher concentrations in diameters of 1 mm and 5 mm, in addition to a flattened curve.

The influence of brine graduation towers on biometeorological conditions, on the example of Ciechocinek spa town (Poland)

The paper provides an analysis of the influence of brine graduation towers on biometeorological conditions, on the basis of the example of Ciechocinek – a spa town in Poland. Using the records of air temperature and relative air humidity in the years 2018-2020 at two locations near Graduation Tower 1 and at the reference site near Spa Hospital No. 1 it was demonstrated that the graduation towers caused a mean drop in air temperature of 0.5–0.7°C with maximum diff erences 7.5°C. The average humidity due to brine evaporation was 3.6–4.6% higher, but maximum differences exceeded 30%. Based on mobile measurements the effects of the graduation tower were found to be limited to its vicinity, where air temperature was lower and humidity higher. The distribution of air temperature and humidity changed depending on wind direction. Cooler and more humid air was carried downwind of the graduation tower. The calculated biometeorological indices showed that neutral, comfortable or refreshing conditions prevailed at the graduation tower and the sensation of heat or thermal stress leading to body overheating was less frequent.

The future poleward shift of Southern Hemisphere summer mid-latitude storm tracks stems from ocean coupling

The latitudinal position of mid-latitude storm tracks has large climate impacts affecting the distribution of precipitation, temperature, humidity, and winds over the extratropics. By the end of this century, climate models project a poleward shift of summer mid-latitude storm tracks in the Southern Hemisphere. Most previous mechanisms for the poleward shift of the storm tracks focused on the role of atmospheric temperature changes. However, the relative roles of other climate system components in the projected storm tracks’ shift have not been examined to date. Here it is shown that thermodynamic ocean coupling is responsible for the future poleward shift of the storm tracks as it overcomes the effect of dynamic ocean coupling to shift the storm tracks equatorward. These results stress the importance of using full-physics ocean models to investigate the future shift of the storm tracks, and of better monitoring ocean coupling processes to improve our preparedness for future climate changes.

Effects of the Operating Parameters of Supersonic Separators on the Supersonic Liquefaction Characteristics of Natural Gas

In this study, a mathematical model for the supersonic condensate flow of natural gas to understand its condensation process in a supersonic separator has been proposed. The effects of export back pressure, inlet temperature, and inlet pressure on the condensation parameters were investigated. The results indicate that the condensation position moves forward with the increase in the inlet pressure and the decrease in the inlet temperature. A method for determining the optimal range of operating parameters (export back pressure, inlet temperature, and inlet pressure) for the supersonic separator is proposed. Within the optimal back pressure range, the region of extreme Mach number in the device should be at the inlet of the straight pipe section after the separation gap, and extreme value distribution areas of low temperature, condensation nucleation, and humidity should be between the nozzle expansion section and the inlet of the straight pipe section. It is important to choose a higher temperature among the optimal values as the inlet temperature and also ensure that the optimal inlet pressure is not higher than the pressure corresponding to the humidity inflection point. At the optimal inlet pressure, the maximum humidity distribution area should be behind the supersonic nozzle expansion section and in front of the inlet of the straight pipe section.

Experimental study and prediction model for non-uniform shrinkage of recycled aggregate concrete in composite slabs

This paper investigates the influence of coarse recycled aggregate (CRA) on the non-uniform shrinkage of concrete with a single surface exposed to the air. A 210 d experiment was conducted on 17 slabs made with recycled aggregate concrete (RAC), measuring the shrinkage strain distribution through the slab depth. The parameters considered included the replacement ratios of CRA, slab depths, and the moisture-transferring boundary conditions (MTBC). The internal relative humidity distribution through the slab depth was monitored to verify the reasonableness of the occurrence of the non-uniform shrinkage. Based on the test results, a prediction model for the non-uniform shrinkage of RAC with a single surface exposed to the air was established and validated. Based on the age-adjusted modulus method, a cross-sectional analysis was conducted on the long-term strains of composite slabs using the proposed model. The investigation results indicated that (1) the incorporation of recycled aggregate significantly increased the shrinkage gradient by 84%−102%; (2) the influence of recycled aggregate on the shrinkage distribution of single-surface exposed concrete increased with a decrease in slab depth; and (3) the proposed equations can accurately predict the non-uniform shrinkage of single-surface exposed RAC.

Comprehensive Review on Climate Control and Cooling Systems in Greenhouses under Hot and Arid Conditions

This work is motivated by the difficulty of cultivating crops in horticulture greenhouses under hot and arid climate conditions. The main challenge is to provide a suitable greenhouse indoor environment, with sufficiently low costs and low environmental impacts. The climate control inside the greenhouse constitutes an efficient methodology for maintaining a satisfactory environment that fulfills the requirements of high-yield crops and reduced energy and water resource consumption. In hot climates, the cooling systems, which are assisted by an effective control technique, constitute a suitable path for maintaining an appropriate climate inside the greenhouse, where the required temperature and humidity distribution is maintained. Nevertheless, most of the commonly used systems are either highly energy or water consuming. Hence, the main objective of this work is to provide a detailed review of the research studies that have been carried out during the last few years, with a specific focus on the technologies that allow for the enhancement of the system effectiveness under hot and arid conditions, and that decrease the energy and water consumption. Climate control processes in the greenhouse by means of manual and smart control systems are investigated first. Subsequently, the different cooling technologies that provide the required ranges of temperature and humidity inside the greenhouse are detailed, namely, the systems using heat exchangers, ventilation, evaporation, and desiccants. Finally, the recommended energy-efficient approaches of the desiccant dehumidification systems for greenhouse farming are pointed out, and the future trends in cooling systems, which include water recovery using the method of combined evaporation–condensation, as well as the opportunities for further research and development, are identified as a contribution to future research work.

Energy-saving Heating System Using Electric Heat Accumulators and Ceiling Fans

An energy-saving heating system using electric heat accumulators and ceiling fans is proposed. A comparative analysis of the distribution of temperature and relative humidity of the air along the height of the preventative hall in the modes of turning off and turning on the ceiling fan was carried out.