Water Heating Research Articles

Carbone-neutral oriented methanol-reforming HT-PEMFC cogeneration based on absorption power refrigeration cycle

Methanol is considered as a promising hydrogen carrier in accelerating the carbon-neutral applications of fuel cell cogeneration. However, the methanol reforming process emits CO2 whose efficient recycling is challenging due to the inevitable power and cooling consumption. To this end, this paper considers the methanol reforming based high-temperature proton exchange membrane fuel cells (HT-PEMFC) cogeneration system, equipped with ammonia absorption power-refrigeration cycle (APRC). The waste heat in the integrated system is utilized for the fuel preheating, evaporation and reforming, driving APRC, and water heating, achieving a cascaded utilization of thermal energy. By building the mathematical models for each subsystem, thermodynamic and economic assessments are investigated. The results confirm that the waste heat of HT-PEMFC is sufficient to drive both methanol reforming and APRC, with additional electricity output from APRC. At a current density of 0.53 A/cm2, the exergy efficiency of the integrated system under the design condition is 0.525 and reaches a maximum value of 0.565 at a reaction temperature of 180 °C and pressure of 1.2 bar. The techno-economic analysis reveals a dynamic payback period of 5.2 years and net present value of 1.14 M$ with a 20-year lifespan of the integrated system.

Effect of Heat Treatment, Water and Vinegar Soaking on Protein and Phytic Acid Levels in Hemp Seed Meal

Hemp plants are notable for their climate resilience, and hempseed meal (HSM) is a potential high-protein feed for poultry. However, HSM has high levels of the antinutritional factor phytic acid (PA). This study aimed to evaluate the effects of heat and soaking treatments on the protein and PA content of HSM. HSM was obtained through cold pressing of whole hempseed and then subjected to heat treatment at 70°C for 24 hours. Soaking treatments involved water, water-vinegar mix, and vinegar for 1, 7, and 24 hours, followed by drying and analysis of PA and protein content. Results indicated that heating increased PA content without affecting protein levels. Soaking duration did not significantly alter protein content but did affect PA levels, with 24-hour soaking significantly increasing PA compared to 1-hour and 7-hour durations. The soaking material also influenced PA content: water soaking increased PA, while a 1-hour vinegar-water mix and 7-hour vinegar soaking significantly reduced PA. The highest PA concentration occurred with 24-hour water soaking. The protein content was highest with 7-hour vinegar soaking. In conclusion, acidic soaking solutions, particularly vinegar and vinegar-water mix, effectively reduced PA in HSM without protein loss.

Simulation of vacuum membrane desalination within an enhanced design of compact solar water heaters

Vacuum Membrane Distillation stands out as a solar desalination method utilizing membrane pressure differentials to evaporate seawater and collect it as fresh water. On the other hand, the new design of compact (or integrated) solar water heaters can be very suitable for Vacuum Membrane Distillation use. In the new design of solar system, its upper part, which is under buoyancy pressure, can have a very suitable space for installing the Vacuum Membrane Distillation system. The purpose of this research is to simulate the proposed design and a dynamic time-domain model was developed for comprehensive simulation, encompassing absorber plate characteristics, collector dimensions, mass flow rate, vacuum pressure reduction, the influence of increasing membrane rows, and seawater concentration. Simulation results showcase the system’s potential, yielding 57.12kg/m2/day of freshwater daily with an average gain output ratio exceeding 1.1. The estimated water production cost is 0.039USD.L-1, along with the generation of 4.3kg.kg/m2/day of chlorine and 0.037g.kg/m2/day of bromine from Mediterranean seawater. For super saline water, the projections indicate a daily production of 104.46kg.kg/m2/day of freshwater with a production cost of less than 0.01 USD/L, a GOR of 1.7, and a daily production of 37.8kg.kg/m2/day of chlorine for a collector area of 6 m2. These outcomes underscore the efficiency and economic viability of the proposed design, positioning it as a promising solution for seawater desalination challenges.

Willingness-to-pay for low-carbon residential heating systems: A discrete choice experiment among Dutch households

Most studies on decarbonizing space and water heating focus on the potential of low-carbon heating technologies from a top-down perspective, while there has been limited research on consumer preferences for low-carbon heat. To address this gap, we conduct a discrete-choice experiment among 1797 individuals in the Netherlands to estimate the willingness-to-pay (WTP) for residential-heating systems. Our results from the latent-class logit (LCL) model indicate that, on average, Dutch households are willing to pay a premium on their current monthly energy bill of 33% for electricity and 29.4% for hydrogen relative to using gas for heat production, 15.3% for reducing the amount of CO2 emissions per kWh of heat with 100 g and 16% for having the option to switch between energy retailers. In contrast, they require a discount of 28.4% for district-heating systems relative to standalone home appliances. Additionally, the class-profiling analysis indicates that individuals with higher education and income levels in the Northern Netherlands have the highest WTP for low-carbon electricity and hydrogen. These findings suggest that policymakers should favor decentralized heating solutions over district-heating systems to facilitate an energy transition in the residential sector. If district-heating systems are implemented, combining them with electricity or hydrogen instead of natural gas is recommended to realize higher consumer welfare.

A cross-sectional study on domestic use of biomass fuel and the prevalence of respiratory illnesses in a rural community in Thaba-Tseka district of Lesotho

The domestic utilization of biomass fuel for purposes such as cooking, space heating, and water heating has been linked to a number of respiratory ailments, particularly when burned inefficiently. However, there is an existing knowledge gap on the impact of this practice on the health of Basotho. This study aims to explore the impact of biomass fuels use on the prevalence of respiratory illnesses among residents of two rural communities in Thaba-Tseka. A quantitative, cross-sectional design was adopted, using a structured questionnaire, to assess the correlation between biomass fuel use and the prevalence of respiratory symptoms and diseases. Data were collected from 326 randomly selected individuals aged 18 and above. The major source of fuel energy used was firewood (39.6 %), followed by paraffin (29.1 %) and animal dung (15.6 %). The most prevalent respiratory symptom reported was cough, among 27.6 % of participants (n = 326), followed by sneezing (n = 326, 23.0 %), and fever (n = 326, 17.5 %). The lowest prevalent respiratory disease was pneumonia (0.9 %) while lung cancer was not reported. The reporting of respiratory symptoms and diseases was most prevalent in January. A greater prevalence of cough was reported by participants with a higher level of education (r (5) = 1.746, p = 0.008). More male participants reported to have tuberculosis (7.8 %) compared to females (3 %) (r (1) = 3.809, p = 0.051). Asthma was noted to be more prevalent among high income earners (r (3) = 8.169, p = 0.043) and those reported to have an employment (r (1) = 4.277, p = 0.039). Surprisingly, there was no association between respiratory diseases and symptoms, and the type of domestic fuel used. In the rural communities of Thaba-Tseka, about 4 in 10 Basotho rural communities, relied on firewood for cooking, space heating and water heating. Respiratory symptoms and diseases were observed mostly in the month of January. Several factors, including education level, marital status, gender, and income level, were significantly associated with specific respiratory symptoms and diseases. Targeted public health interventions are urgently needed to mitigate respiratory symptoms and diseases in the rural communities of Lesotho. More focus should be directed to health behavioral change and provision of improved stoves for exposure reduction of biomass emissions.

High-density and anti-clogging three-phase absorption heat storage with crystallization management

Three-phase sorption heat storage can significantly enhance the energy storage density (ESD) through the crystallization of salt-water working pair. However, the crystals will cause the clogging of solution circulation, making it difficult to be realized in absorption heat storage with liquid absorbent. In this work, the crystal management strategy is proposed for three-phase absorption heat storage. By controlling the crystallization ratio, energy storage enhancement and clogging prevention can be achieved simultaneously. Both theoretical and experimental analyses were carried out. A detailed thermodynamic model of the three-phase absorption heat storage cycle was established, by considering the change of crystallization ratio. A prototype of LiBr-water three-phase absorption heat storage with crystallization management which includes crystal filtering, high-level solution intake, crystal fusion by electric heating rods, and water flushing, was designed and fabricated. The anti-clogging design ensures the circulation of solution, efficient vapor absorption and crystal dissolution in discharging process, thus achieving high energy storage density and stable heat output simultaneously. The three-phase absorption heat storage prototype demonstrated high ESD of 220 kWh/m3 and 178 kWh/m3 with crystallization ratio of 0.41 and 0.26 under the space heating and hot water supplying conditions, respectively. Comparing with the absorption heat storage prototype without crystallization, this represents ESD enhancement of 102% ∼ 210%, which confirms the feasibility and superiority of the proposed crystal management strategies.

Investigation of a high-temperature combination heat pump for lower-cost electrification in multifamily buildings

The development of space and water heating combination heat pumps capable of generating water temperatures high enough for convective heat emitters will enable more cost-effective and equitable decarbonization solutions for electrifying multifamily buildings. In this paper, multifamily building models and a charge-sensitive mechanistic cycle model of a combination heat pump are developed, and the system performance is predicted based on the models. Unlike other state-of-the-art residential heat pumping equipment, the modeled combination heat pump using an economized, fluid-injected variable-speed compressor can achieve higher temperature lifts of 40° – 85°C, with lower installation costs and complexity. The model predicted heating coefficient of performance (COPh) is 2.1 at an ambient temperature of −15°C with a high-temperature lift of nearly 85°C, and a seasonal coefficient of performance in heating mode (SCOPh) ranges from 2 – 4 for different locations. The system shows 30% – 90% lower CO2eq emissions over a condensing gas boiler and 9% – 13% lower projected installation costs than two separate space and water heat pumping appliances.

Effect of geometric parameters on the heat transfer performance of a submerged coil condenser for heat-pump water heating

Water heating with heat pumps can contribute to reduce carbon dioxide emissions and meet sustainability goals due to its high thermal efficiency, versatility in terms of alternative energy sources and thermal energy storage capability. In this study, the heat transfer of the condenser subsystem of an accumulation heat-pump water heater is analyzed by means of 2D CFD simulations. After validating the simulation methodology with benchmark natural convection problems, the influence of different geometric parameters of the condenser coil on the heat transfer is studied, which include the distance between turns and the distance from the tank wall. For each case, Nusselt number correlations in terms of Rayleigh number are found via power-law fitting. According to the CFD results, a greater coil pitch improves the average heat transfer. Moreover, a shorter distance from the tank wall generates a velocity field that laterally diverts the plume that forms around each turn. Hence, the heat transfer is enhanced because the preheating effect from downstream turns is mitigated, while the velocity gradients are strengthened. Additionally, a condenser design is proposed with geometric parameters that promote effective heat transfer, and the performance is compared against a reference design with geometric parameters that limit the heat transfer but are common in commercial solutions. The proposed geometry has a 43% increase in the Nusselt number, with respect to the reference geometry. Also, based on a dynamic simulation model of heat pump performance, it is determined that, for the same operating conditions, the proposed geometry improves the overall coefficient of performance (COP) of the system by up to 7%. These results highlight the importance of the geometric design of the condenser in heat-pump water heating systems, since they can contribute to a better overall performance and a more efficient thermal storage.

Experimental Investigation of Thermo-Hydraulic Characteristics and Sustainability Measure of a Novel Multi-Fluid Heat Exchanger for Turbulent Water-Based Nanofluid Flow through the Inserted Brazed Helix Tube

Abstract A Novel Multi-Fluid Heat Exchanger (NMFHE) deployed for simultaneous heating of water and space is experimentally investigated to predict its thermo-hydraulic, exergetic, and sustainability performance for distinct Al2O3, TiO2, and CuO nanofluid flow of 50ppm concentration of each through the inserted Brazed Helix Tube (BHT). The input parameters such as flow rates, helix tube diameters, and nanofluid types are varied throughout the experiments to evaluate their effect on output performance parameters i.e., Nusselt number (Nu), Friction factor (f), entropy generation number (Ns), JF factor (JF), exergy efficiency (εE), and sustainability index (SI). The nanofluid (NF) flowing through the BHT is the heating fluid that simultaneously heated the cold water (CW), and air (CA) flowing through the outer shell and inner conduit of the BHT respectively. A distinct Nusselt number correlation for turbulent nanofluid flow inside BHT was developed, compared, and validated reasonably with the current result. For Al2O3 NF at a Reynolds number of 5698 with a 1/2-inch diameter helix tube, the best results for JF, εE, and SI are found to be 0.009, 0.72, and 3.53, respectively. Furthermore, for Al2O3 and TiO2 NF at a Reynolds number of 14250 and a helix tube diameter of 1/4 and 1/2-inch, f, and Ns are found to be 0.0032 and 0.043, respectively are optimum. It is observed that the use of Al2O3 NF, higher helix tube diameters, and lower flow rates all make the proposed heating application more sustainable.

EXPERIMENTAL INVESTIGATION OF NATURAL CIRCULATING SOLAR ENERGY SYSTEM INCLUDING A PARABOLIC TROUGH SOLAR COLLECTOR

Abstract The most common natural flow water heating systems are in one-ended inclined pipes today. In this study, it is aimed to investigate the natural circulation solar energy system experimentally with parabolic trough solar collector. For this purpose, a natural circulation solar energy system including a parabolic trough solar collector that follows the sun in one dimension on the N-S axis in the outdoor environment has been established. Experiments were conducted on different dates. The radiation values coming into the opening of the moving collector were calculated. With the SolTrace program, it has been found that 56 % of this radiation can reach the vacuum tube glass pipe in the focus of the collector. In addition, the Rayleigh number was calculated for each experiment for the section of the glass tube close to the tank inlet, and it was monitored whether there was natural circulation throughout the experiment. As a result, the average Rayleigh number in the experiments conducted on 13 February, 31 March, 24 April, 23 May, 9 June, and 6 July was 1.4E+06, 7.6E+05, 7.8E+04, 2.2E+04, 3.1E+05, respectively. and calculated as 2.8E+05. In the experiments on May 23 and April 24, when the cooling system was open, it was observed that the Rayleigh number constantly dropped below the critical value. In other experiments, the situation is the opposite, and the natural flow is continuous.

Performance Analysis and Techno-Economic Evaluation of Solar Energy Retrofitting for Coal-Fired Power Plant in Central Kalimantan Province

The power generation sector significantly contributes to climate change. Mitigation efforts are crucial to adhering to the global commitment to limit temperature increases below 2°C. One potential solution is retrofitting existing power plants with technologies that integrate renewable energy. This study explores the integration of solar energy into the operational processes of a coal-fired power plant in Central Kalimantan, replacing the extraction steam turbine in the high-pressure feed water heater No. 7. Using STEAG EBSILON for simulation, this research evaluates the power plant's performance before and after retrofitting in both power-boost (PB) and fuel-save (FS) modes under varying load conditions. The results demonstrate that thermal efficiency in both PB and FS modes increased by up to 2% compared to the base scenario. Specific fuel consumption decreased by 15.05 g/kWh in PB mode and 15.75 g/kWh in FS mode, leading to a reduction in coal consumption and CO2 emissions by 4.69% and 4.94% respectively. Additionally, the study observed that the solar percentage and solar-to-electricity efficiency increased as the load decreased. In FS mode, the solar electricity proportions at VWO, 100%, 75%, and 50% load rates were 5.23%, 5.53%, 7.76%, and 11.92%, respectively. The levelized cost of energy (LCOE) for solar electricity was calculated to be 431.82 IDR/kWh, with an expected investment return period of 5.87 years.

Investigation of anchor ice evolution in rivers and the impact of hydrometeorological conditions

The evolution of anchor ice during river freeze-up is known to significantly influence sediment transport, fish habitats, and river hydrology during winter. It may also lead to the formation of anchor ice dams and the generation of anchor ice waves that can cause flooding. Many of the previous field studies of anchor ice focused on the conditions leading to its formation and release, its crystal structure and properties, and the evaluation of its impacts. However, direct measurements of the temporal variation of anchor ice in rivers are rare, which has limited our understanding of this important and dynamic ice form. In this study, six anchor ice events were measured on two Canadian rivers using an underwater camera system, accompanied by comprehensive measurements of weather and hydraulic data and frazil ice concentrations. The temporal evolution of anchor ice was observed to occur in one of three stages: growth, stable, or decay. The direction (i.e., upward or downward) and trend of the net air–water heat flux reliably indicated the timing of these three stages. Anchor ice growth in the majority of events was through a combination of frazil accretion and in-situ crystal growth, resulting in event-averaged growth rates from 0.48 to 1.77 cm/h. Anchor ice grew solely through frazil accretion when snowfall occurred, with event-averaged growth rates from 1.64 to 3.53 cm/h. Anchor ice decay occurred through the thermal thinning of accumulations at an average decay rate of −0.48 to −2.52 cm/h. Anchor ice release was controlled by thermal factors and always occurred after the end of supercooling. Frazil accretion rates were estimated using measurements of anchor ice growth rates and suspended frazil concentrations and ranged from 2.6 × 10−3 to 6.0 × 10−3 m/s.

Modeling and manufacturing of solar modules of different designs for energy supply of biogas plant

The article presents a description of the modeling and manufacturing of solar modules of photovoltaic, thermal and photovoltaic thermal designs intended to supply energy to a biogas plant intended for the production of biohydrogen and biomethane. Mathematical modeling of the photovoltaic module was carried out and the calculated temperature of the photovoltaic converters was determined, and also the photovoltaic module was manufactured using the process of sealing the photovoltaic converters with a two-component polysiloxane compound. Mathematical modeling of a solar thermal collector with water radiators in the form of a round copper tube, an oval copper tube, as well as a rectangular water cooling channel (“water jacket”) was also carried out, in which pressure losses and the amount of water heating were assessed. The distances between the rectangular channels of the water-cooling radiator for uniform heat removal were determined, and mathematical modeling of the thermal state of a solar thermal collector with a semicircular cross-section of the water-cooling radiator channel was carried out, after which the solar thermal collector was manufactured. Mathematical modeling of the total displacements of the components of a photovoltaic thermal module, the values of which do not exceed acceptable limits, was carried out, after which a photovoltaic thermal module was manufactured using the process of sealing photovoltaic converters with a two-component polysiloxane compound.

Experimental analysis on the thermoelectric effect of various solid-state devices used for direct conversion of thermal energy into electrical energy

In this present investigation, the performance of thermoelectric generators (TEGs) was determined for the TEGs made of lead telluride (PbTe3), bismuth telluride (Bi2Te3), silicon germanium (SiGe), and aluminum oxide (Al2O3). In response to variations in the heat input rate and water flow rate, the electric power generated by the TEG was recorded and studied for the aforementioned TEG materials. During the investigation, the water flow rate to the TEG's cold side was chosen to be 0.5 lpm to 2 lpm in the step of 0.5 lpm, and the thermal energy input rate to the hot side was set at 30 W–120 W in the step of 30 W. Among all the TEGs Bi2Te3 was superior in terms of power generation potential in comparison to other TEGs in all the test conditions. The investigation also reveals that all TEGs appear to have a high-power generation when the cooling water flow rate was 2 lpm and the heat input rate was 120 W. At a water flow rate of 2 lpm for the case of Bi2Te3, the power generation potential was elevated by about 20.3 %, 14.4 %, and 6.5 % in comparison to Al2O3, PbTe3, and SiGe respectively.

A solar-driven hygroscopic aerogel using electrical impedance tomography for exploiting differentiated photothermal interfaces

Photothermal materials and structures are essential for the actual performance of interfacial solar-steam generation systems in atmospheric water harvesting (AWH) technologies. However, the absence of theoretical insights into water desorption, diffusion, and heat transfer at the photothermal interface can impede the development of efficient solar interfacial AWH technologies. To address this gap, we introduce an in-situ imaging approach utilizing the electrical impedance tomography (EIT) system to dynamically visualize the water desorption process within aerogels in real time. The visualization outcomes highlight that the effectiveness of moisture desorption in aerogels is influenced by critical factors, including heat concentration, the localization of heating and cooling, and minimal diffusion resistance. Furthermore, the microstructure and temperature disparities on different sides drive internal water movement and evaporation. The proposed design of the generalized EIT visualization detection system aims to reveal the desorption kinetics of highly efficient solar-driven AWH materials, paving the way for a new frontier in studying the interfacial solar-steam generation process.

Optimal Disturbance Control for Energy Feedback of Gas Water Heaters

Optimal Disturbance Control for Energy Feedback of Gas Water Heaters

Thermal and electrical performance analysis of a lightweight micro CHP system for recreational vehicles

For comfortable use of a Recreational Vehicle (RV), there is a need to supply electrical energy to recharge the batteries and supply the installed equipment, as well as thermal energy, for hot water and ambient heating. A conventional solution for supplying electrical energy is the installation of photovoltaic modules combined with connection to an electrical grid, when possible. Water heating is generally done using a passage gas heater or hybrid gas/electric storage heater. Imported vehicles have gas heating and many other vehicles have diesel heaters. To develop an alternative to currently available energy supply methods, this work proposes the creation of a cogeneration system for RVs. From a literature review, a research gap was identified in relation to micro CHP devices for RVs. In the development of this work, a micro CHP prototype was created, with 980 W of maximum electrical power, consisting of a single-cylinder internal combustion engine, an automotive alternator and heat exchangers for heat recovery. The prototype was enclosed and instrumented, allowing to evaluate the thermal power obtained in water flowing through exhaust gases, lubricating oil and cooling air heat recovery systems, in addition to measuring the electrical power of the alternator. Operational tests were carried out with 46 different test conditions, combining variations in the engine speed (N) and in electrical load. The prototype electrical efficiency reached 10.18 % ±0.2 % at 3008 rpm with 83 % load. The maximum electrical power was 0.746 kW±0.015 kW at 3637 rpm and 100 % load. The maximum thermal energy recovery rate was 3.267 kW±0.039 kW. Utilization factor reached 65.57 % ±0.33 % at 3208 rpm with 63 % load. Compared to traditional means of providing electrical power and thermal power for RVs, the prototype proved to be more advantageous when the demand is for electrical power and space heating. However, for conditions in which the demand is for electrical power and water heating, or just electrical power, the current solutions available are still more efficient.

The Phase Change Heat of Water in the Pore Space of Rocks Based on DSC Studies.

This research investigates the phase change behavior of water within the pore space of Devonian carbonate rock samples using Differential Scanning Calorimetry (DSC) across a temperature range of -80 to 0 °C. This study focuses on dolomite and limestone samples, all with porosities below 3%, an area not extensively covered in previous literature. Significant endothermic effects were observed at temperatures below -2 °C, challenging conventional understanding. The study reveals that the latent heat of phase change in these systems can exceed 334.2 J/g, the known value for bulk water, indicating unique thermodynamic properties of water in confined spaces. For the dolomite rock sample, observed endothermic heat effects below -2 °C were 23.5% and 26.7% of total phase change energy. The cumulative pore volume calculated using the thermoporometry method was found to be higher than expected from water occupancy alone, independent of assumptions about the thickness of the adsorbed unfreezable water layer or pore shape (spherical or cylindrical). This research provides novel insights into unfrozen water content calculations, significantly enhancing frost durability assessments and the geoengineering industry.

Highly efficient sweat transmission of double-layer variable pore textile for human healthcare and comfort regulation

Healthcare medical textiles require local microclimate control over sweat transmission and evaporation. However, existing strategies mainly focus on complicating the preparation process or sacrificing breathability and comfort. Herein, we design a lightweight and scalable knitted fabric featuring a double-layer structure consisting of hydrophilic ultrafine polyester and hydrophobic conventional yarns to achieve high moisture transport. These fabrics displayed an ideal directional water transport ability (one-way moisture transport capacity 718%) and anti-regurgitation compared with common cotton fabric. By distributing pores within the textile structure, these fabrics additionally exhibited beneficial water evaporation and heat dissipation. Simultaneously, the theoretical calculation verified that while the bottom layer has increased fiber density and looping area, fabrics are conductive to unidirectional moisture transport. These findings highlight the potential of variable pore knitted textile for personal sweat management, healthcare comfort regulation, and the relief of global energy issues.

Evaluation of Climate Suitability for Maize Production in Poland under Climate Change

Climatic conditions are the main factor influencing the suitability of agricultural land for crop production. Therefore, the evaluation of climate change impact on crop suitability using the best possible methods and data is needed for successful agricultural climate change adaptation. This study presents the application of a multi-criteria evaluation approach to assess climate suitability for maize production in Poland, for a baseline period (BL, 1981–2010) and two future periods 2041–2070 (2050s) and 2071–2100 (2080s) under two RCP (Representative Concentration Pathways) scenarios: RCP4.5 and RCP8.5. The analyses incorporated expert knowledge using the Analytical Hierarchy Process (AHP) into the evaluation of criteria weights. The results showed that maturity and frost stress were the most limiting factors in assessing the climatic suitability of maize cultivation in Poland, with 30% and 11% of Poland classified as marginally suitable or not suitable for maize cultivation, respectively. In the future climate, the area limited by maturity and frost stress factors is projected to decrease, while the area of water stress and heat stress is projected to increase. For 2050 climate projections, water stress limitation areas occupy 7% and 8% of Poland for RCP4.5 and RCP8.5, respectively, while for 2080 projections, the same areas occupy 12% and 32% of the country, respectively. By 2080, heat stress will become a limiting factor for maize cultivation; according to our analysis, 3% of the Polish area under RCP8.5 will be marginally suitable for maize cultivation because of heat stress. The overall analyses showed that most of Poland in the BL climate is in the high suitability class (62%) and 38% is moderately suitable for maize cultivation. This situation will improves until 2050, but will worsen in the 2080s under the RCP8.5 scenario. Under RCP8.5, by the end of the century (2080s), the highly suitable area will decrease to 47% and the moderately suitable area will increase to 53%.