Moderate Climate Zones Research Articles

Study of Electrochromic (EC) and Gasochromic (GC) Glazing for Buildings in Aspect of Energy Efficiency

Abstract The paper analyzes the impact of switchable glazing: electrochromic (EC) and gasochromic (GC) on the energy efficiency of the building. Using the analytical and comparative method, the energy-relevant EC and GC glazing features were defined. Secondly, experimental studies on the energy-saving role of EC and GC glazing in various climatic zones were analyzed. The paper aims to define this role. The analyzes were referred to the thermal and lighting aspects. Comparisons were made between the EC and GC technologies, as well as with traditional - “static” types of glazing. The analysis showed differences in the technical characteristics of both technologies. Despite the differences, the results prove a beneficial effect of EC and GC glazing on the reduction of usable energy consumption in the building. The impact is most significant in terms of relieving the cooling and air conditioning systems. In this field, EC glazing was determined a more favorable technology. Further detailed research is required, focusing mainly on the lighting aspect for moderate and cold climate zones. The research was summarized with a collective evaluation of the energy-related role of EC and GC glazing.

Effect of Genotype × Environment Interaction for Seed Traits in Winter Oilseed Rape (Brassica napus L.)

Brassica napus (L.), winter oilseed rape (WOSR) or canola, is one of the most important oilseed crop species of the moderate climate zone. Improving the seed quality and yield makes the main target in breeding programs worldwide. In this study, we examined the genotype-by-environment (G×E) interaction with respect to six seed traits among 25 WOSR genotypes. The plant material included the registered canola cultivars, our newly developed mutant breeding lines and the Ogura F1 hybrids and their parental components, in addition to our domestic breeding lines including two semi-resynthesized (semi-RS) lines. The 25 genotypes were examined in field trials at two locations, in three growing seasons. Seed oil and protein content, total glucosinolates (GLS) content in seed meal and C18 unsaturated fatty acid (oleic, linoleic and linolenic) composition in seed oil were examined. The additive main effects and multiplicative interaction (AMMI) analyses revealed significant effects of both, genotype (G) and environment (E) as well as the G×E interaction regarding the analyzed seed traits. In our study, two Ogura F1 hybrids, a CMS line and a new high oleic mutant breeding line revealed high stability and good average values for most of the analyzed seed traits, thus making a valuable source of starting materials for further improvement.

Is it a possibility to achieve energy plus prefabricated building worldwide?

Abstract Prefabricated buildings constructed to be used in a specific region cannot be assumed to work unconditionally in different climates around the world. It is important to develop passive house solutions for each location, suitable for the actual climate and geographic conditions. Shelters could be used in different applications such as refugee housing or telecommunication stations. Photovoltaic energy could cover the electricity consumption of these shelters. Shelters for different applications should be usable in all weather conditions, and because of that different climate zones were chosen. A full study about three climate zones was done to study the different factors that play a significant rule in choosing the location of the shelter. In this study, prefabricated housing was designed to ensure thermal comfort by doing structure design changes and using solar energy as an energy source. Three different locations have been chosen to be able to perform the best structure and components design for every location, taking into consideration the assumptions taken in each place. The total photovoltaic system was designed with a capacity of hot, moderate and cold climate zones with 2.0, 1.8 and 3.45 kWp, respectively, along with energy plus the production of 38% in the hot, 47% in the moderate and 28% in the cold climate.

Daylighting and overall energy performance of a novel semi-transparent photovoltaic vacuum glazing in different climate zones

Amorphous silicon-based semi-transparent photovoltaic windows can produce renewable electricity and offer a certain amount of natural daylight for occupants. However, it has a deficiency as the absorbed solar energy would be partially transferred into additional cooling demand in summer. In this respect, a novel semi-transparent photovoltaic vacuum glazing is proposed to improve energy performance. The selection of appropriate glazing of an energy-efficient building should take into consideration the specific climate conditions. The daylighting behaviour of the glazing will also affect the daylighting performance as well as the lighting consumption. In this paper, the thermal performance, daylighting performance and overall energy performance of the proposed vacuum PV glazing in different climate regions have been investigated. A daylighting model was conducted by DAYSIM to evaluate the annual daylighting performance. It was found that the vacuum PV glazing can balance daylighting availability and visual comfort by providing sufficient daylight in the anterior half of the room and reducing daylight glare to the minimum level. The energy simulation by EnergyPlus demonstrated that the vacuum PV glazing has the energy-saving potential up to 43.4%, 66.0%, 48.8%, and 35.0% in Harbin, Beijing, Wuhan and Hong Kong, respectively. However, the applications of the vacuum glazing lead to additional cooling consumption in the moderate climate zone, such as Kunming. The results advanced the understanding on the applicability and limitation of the vacuum PV glazing in different climate backgrounds. Furthermore, the reversed and the reversible vacuum PV glazing were proposed to enhance the adaptability. The results suggest that the reversible vacuum PV glazing can act energy response in a more efficient way and fully utilize the energy-saving potential of the integration of the PV glazing and the vacuum glazing.

An investigation of ventilation control strategies for louver windows in different climate zones

Guaranteeing high indoor air quality and high degree of usersatisfaction at the same time is one of the challenges when improving the energy efficiency, namely the energy consumption, of a building. Current non-residential buildings mainly use mechanical ventilation systems to ensure high air quality. Natural ventilation can be an alternative regarding to lower maintenance costs and the psychological feeling of fresh air. Present natural ventilated buildings pose the risk of higher energy demand and less indoor air quality due to user’s behaviour. Controlled natural ventilation based on indoor CO2 concentration and room air temperature is needed. However, the energy efficiency of a control strategy highly depends on climate zone and control parameters. This paper aims to explore the impact of different control strategies on the energy efficiency of an operable louver window. The analyses are done for yearly results and then for each month individual to clarify the effect of monthly varying control strategies. For the analysis EnergyPlus as a building energy simulation tool and for the natural ventilation in specific the EnergyPlus Design Flow Rate method is used. In the simulation four window opening strategies based on CO2 concentration and one simple intake/exhaust mechanical ventilation system were tested in Mediterranean, subtropical and moderate climate zone. The highest impact on energy efficiency and thermal comfort was seen at the cold months in the moderate climate. Long window opening strategies cannot be implemented because of a high thermal discomfort. In the hot months in the Mediterranean and subtropical climate an impact of ventilation strategies are seen as well. Only at moderate conditions no major differences in the natural ventilation strategies were observed. When comparing the natural ventilation conditions to mechanical ventilation major differences were found. In almost all climate conditions natural ventilation outperformed the mechanical ventilation. Only in winter months in the moderate climate mechanical ventilation outperforms natural ventilation.

Freezing-thawing impact on aggregate stability as affected by land management, soil genesis and soil chemical and physical quality

Soil structure formation and soil aggregate stability are affected by anthropogenic and natural environmental factors and are of great interest worldwide. The goal of this paper was to determine the effect of soil freezing-thawing processes on the formation of water-stable aggregates (WSA) in two soil types – Cambisol (Central Lithuania) and Retisol (Western Lithuania) in relation to soil organic carbon content (SOC), type of land use and soil tillage intensity. Three successive freezing-thawing cycles were implemented in a laboratory at three soil water contents (air-dry – WSAAD, field capacity – WSAFC and near full saturation – WSANS) on soil cores taken from the 0 to 10, 10 to 25 and 25 to 40 cm layers of long-term conventional tillage (CT) and reduced tillage (RT) field trials of arable land as well as from the forest soil. Soil bulk density (BD), Ntotal, C/N ratio, Ptotal, and Ktotal were determined.WSA content in the Cambisol was significantly lower than in the Retisol at all soil water contents. WSA, averaged across soil types, land uses and soil depths, tended to decrease in the following order: air-dry soil > soil with water content at field capacity > soil near full saturation. In the Cambisol, CT management led to a 3.4-fold lower WSA under air-dry soil conditions, compared to the forest soil. In the Retisol, at all soil water contents, CT decreased WSA content 2.2-, 2.1- and 2.7-fold, respectively, compared to WSA in the forest soil. RT management in the Retisol increased the amount of WSA compared to CT through higher SOC content and lower soil BD. In the Cambisol and the Retisol, the SOC content acted as a direct factor for WSAFC. High soil BD acted as an indirect negative factor for aggregate stability at all three soil water contents. The potential of WSA in the Retisol for functioning and sustaining better WSAFC within the whole 0−40 cm soil layer is higher than the potential of WSA in the Cambisol. This study demonstrates that long-term RT management ensured higher WSAFC content than CT. Water-stable aggregate in the Retisol for functioning and sustaining better WSAAD is higher than in the Cambisol. If dry meteorological conditions prevailed in moderate climate zone, RT management would have a promising future for soil sustainability by maintaining higher WSA.

Techno‐economic comparative study of hybrid microgrids in eight climate zones of Iran

AbstractMany efforts have been made to increase the utilization of renewable energy resources (RESs) in Iran. This paper aimed to evaluate the techno‐economic performance of an introduced hybrid microgrid (HMG) in eight climate zones of Iran. Therefore, ten cities are selected from the eight climate conditions of Iran. An electricity pricing strategy is also implemented according to the electricity tariffs defined by the Ministry of Energy (MOE) of Iran. The proposed electricity pricing strategy is applied to the HOMER software for investigating the optimal system configuration, RES electricity generation, and the economics of each understudy city. Optimization results indicate that Urmia (in moderate and rainy climate zone) has the least net present cost (NPC) (−5839$) and levelized cost of energy (COE) (−0.0122 $/kWh), whereas Golestan (in semimoderate and rainy climate zone) has the highest NPC (4520 $) and COE (0.012 $/kWh). It is shown that the combination of photovoltaic (PV)/wind turbine (WT)/converter in the grid‐connected operation mode is the most economical configuration. Moreover, the cities with higher potentials of wind speed and solar irradiance have lower NPC and COE. It is concluded that the utilization of the battery energy storage (BES) is technically and economically infeasible for all eight climate zones, even if the stored electricity is sold to the grid. Two sensitivity analyses are conducted to the electricity feed‐in‐tariff (FiT) and solar module price, respectively. The first sensitivity analysis indicates that by increasing FiT, more contribution of RESs is seen, which leads to lower COE and NPC. Furthermore, the two cities of Urmia and Yazd have the highest NPC and COE reductions. The second sensitivity analysis studies the module price impacts on the NPC and COE of each understudy city. It is revealed that the PV module price has a considerable effect on NPC and COE. However, this effect is more significant in some cities such as Bam, where a linear relationship is seen between the module price and economic results (NPC and COE).

Quality Parameters of Kiwiberries Grown in the Czech Republic

Abstract The present study evaluated the quality of kiwiberries produced in the territory of the Czech Republic in 2018 and 2019. Actinidia arguta is a very hardy and flexible species which can produce fully ripe fruits even in the setting of moderate climatic zones unlike commercially available A. chinensis as a variety which needs a longer season with higher temperatures to become fully ripe. Once harvested, the fruit was studied for soluble solids content, titratable acidity, antioxidant activity and the content of malic, citric and ascorbic acids. Unlike commercially available kiwifruits, kiwiberries lack hair and can be consumed unpeeled. The results of the present study confirmed the notable potential of kiwiberries consisting namely in the levels of antioxidants present in the skin of the fruit. Kiwiberry fruits feature a higher level of acidity than is common in conventional commercial varieties of A. chinensis as citric acid is the type of acid prevailing in the fruit at all times.

Evaluation of Thermal Comfort in the Traditional Bourgeoisie Houses in Beirut

The increasing of energy demands has considerably increased the requirements for new and traditional buildings in different climate zones. Unprecedented heat waves have increased climate temperature, in particular, in moderate climate zones such as Lebanon. In Beirut, only the residential sector consumes 50% of total electricity consumption. HVAC (Heating, Ventilation and Air conditioning) systems are used to reach acceptable thermal comfort levels in the new residential buildings. In case of the traditional bourgeoisie houses in Beirut, there are no discussions about the use of HVAC systems to achieve the required thermal comfort level. Thus, to reach an acceptable thermal comfort level, these houses which already contain natural ventilation system shall adapt the modern thermal comfort requirements and thermal comfort strategies and technologies where their architectural features and existing materials condition the available solutions. In order to identify the best options within the possible intervention lines (envelopes, passive strategies, equipment, renewable energy systems), it is necessary to perceive the real performance of this type of houses. In this context, the article presents the results of the study of thermal performance and comfort in a three case studies located in Beirut. Detailed field data records collected are analyzed, with a view to identify the indoor thermal environment with respect to outdoor thermal environment in different seasons. Monitoring also included measurement of hygrothermal parameters and surveys of occupant thermal sensation.

Critical THI thresholds based on the physiological parameters of lactating dairy cows.

The severity of heat stress conditions in high-yielding dairy cows is currently underestimated. The present study aimed to determine the heat load threshold of the temperature-humidity index (THI) on physiological parameters of lactating Holstein-Friesian cows under a continental climatic zone in Germany. Physiological parameter measurements, such as respiration rate (RR), measured hourly, and heart rate (HR) and rectal temperature (RT), both measured twice daily, were performed in a total of 139 multiparous cows on three randomly chosen measurement days per week. In addition, the ambient temperature and relative humidity of the barn were recorded every 5min to calculate the current THI. The physiological parameter data were linked to the THI, and the heat load thresholds were determined using the broken-stick model. The heat load duration effect of each physiological parameter was obtained by regression analysis. Considering the increases in the physiological parameters, our study provided reliable data to determine heat load thresholds for lactating high-yielding dairy cows in a moderate climatic zone. The heat load threshold could be determined for RR in standing cows (THI=70) and lying cows (THI=65) and for HR (THI=72) and RT (THI=70) in standing cows. The heat load duration also demonstrated a significant effect on the increases in physiological parameters among dairy cows. In particular, the present study enabled a strategy to be devised to initiate heat mitigation in high-yielding dairy cows when they are exposed to THIs above 65.

Mineralogy and Geochemistry of Fluvial-Lacustrine Pisolith Micronodules from the Roztoka Odrzańska, Odra River, NW Poland

Small-sized ferruginous micronodules or pisolith nodules, frequently occurring in inland freshwater systems in moderate climate zones, are important indicators of groundwater level changes and early diagenetic processes, especially within the Pleistocene post-glacial sedimentary systems, including swamps, peatbogs, rivers, or lakes. Compared to the other geochemical environments, pisolith nodules are usually dominated by iron hydroxides and oxides. In most cases, described micronodules indicate high phosphatization, significant contribution of allogenic detrital components, and low manganese content. The major aim of the article is to present textural, geochemical, and mineralogical variability of pisolith nodules recovered from the Roztoka Odrzańska, Odra river mouth area, NW Poland. We describe genetical relations between different types of pisoliths and try to interpret the possible formation phenomena. Analyzed loose ferruginous micronodules were separated from the lacustrine silty-clayey sapropel muds and gyttja, later analyzed using optical microscopy, SEM-energy dispersive x-ray (EDX), and XRD methods. As a reference material, we use archival iron bog ores and geochemical data of different types of nodules. Additionally, we describe previously unknown siderite-rich nodules found in neighboring sites of the Dąbie Lake and the Szczecin Lagoon.

Influence of Solar Reflectance and Renewable Energies on Residential Heating and Cooling Demand in Sustainable Architecture: A Case Study in Different Climate Zones in Spain Considering Their Urban Contexts

In this research work, energy simulation was used as a forecasting tool in architectural design. It includes the study of a multi-family residential building in five different climate zones of Spain, i.e., A4 (very hot climate zones), B4 (hot climate zones), C4 (moderate climate zones), D3 (cold climate zones), and E1 (very cold climate zones). The authors accomplished a sensitivity analysis in order to identify the influence of passive strategies (i.e., with regard to solar reflectance) and renewable energy (i.e., with regard to aerothermal energy) on indoor temperatures and energy demands. The increment in indoor temperatures depends on the neighboring buildings so that effect of urban contexts as a source of protection against sunlight is also considered. The increment in the albedo (i.e., the solar reflectance) of the façade during the winter period produces little differences in indoor operative temperatures. On the contrary, during the summer period, it produces large temperature differences. Therefore, it is shown that colors significantly reduce temperatures from 1.24 to 3.04 °C, which means considerable annual energy savings. This research demonstrates that solar reflectance can reduce the air indoor operative temperature down to 4.16 °C during the month of May in the coldest climate zones. As a result of the simulations, it is noted that the coldest climate zones are influenced to a greater extent by the inclusion of their urban contexts in the simulations. However, the heating demand, without considering it, becomes lower. Therefore, ignoring the urban context produces important errors in the heating analysis (12.2% in the coldest climate zones) and also in the cooling analysis (39% in the hottest climate zones). Finally, the use of renewable energy in the configuration of a model with a high urban canyon (Hc), as well as with an east–west building orientation and a low albedo produces a difference of around 76% in the cooling costs within the hottest climate zones and around 73% in the heating costs within the coldest climate zones. The results of this study can be applied as a guideline in early architectural design.

Performance operation of liquid ejectors for a R744 integrated multi-ejector supermarket system using a hybrid ROM

Performance maps were generated for designed liquid ejectors installed in a multi-ejector module in an R744 integrated supermarket system using a hybrid of the reduced-order model (ROM). Hybrid ROMs of the investigated liquid ejectors were developed based on experimental data and CFD results. The CFD model achieved satisfactory accuracy at motive nozzle pressures above 59 bar, and the hybrid ROM improved the mass flow rate prediction. Maps were generated for the motive nozzle mass flow rate and the mass entrainment ratio at different ambient conditions related to cold, moderate, and hot climate zones. The set of the pressure lift for ejector efficiency maximisation at different ambient conditions is presented for refrigeration and air-conditioning applications. The developed liquid ejectors hybrid ROMs can be used to optimise work of the R744 integrated supermarket system equipped with the vapour and liquid ejectors.

The influence of the basil on colour, odour and taste of frankfurters

Plants from the moderate climate zone are rarely used as seasoning in pasteurised sausages. Seasoning plants of the family Lamiaceae belong to this group (marjoram, basil, savory, sage, thyme). One of the reasons these herbs are rarely used to season meat products is the presence of the plant pigment, chlorophyll that can have undesirable influence on colour, odour and taste of meat products. The aim of this paper was to assess the influence of basil on colour, odour and taste of vacuum-packed frankfurters during 28 days of storage. Powdered, dried basil (0.1%, 0.3% and 0.5%) was added to frankfurters while control frankfurters were produced without herbs or spices. Assessment of colour, odour and taste acceptability of the frankfurters was performed by a panel of five assessors using a quantitative descriptive test, and the results of the ranking test were analysed statistically. When used at the level of 0.1% in the sausages, basil did not have negative influence on frankfurter colour, while larger quantities 0.3% and 0.5% adversely affected frankfurter colour. Basil in the smaller amounts of 0.1% and 0.3% stimulated development of a pleasant odour and taste in the frankfurters, while 0.5% basil had an undesirable effect on these sensory attributes.

Energy performance of PV integrated office buildings with fan-assisted double skin façades under tropical climates

ABSTRACTBuilding upon the knowledge accumulated from a comprehensive research program on double skin façades (DSFs), this study explores two design enhancements for buildings in tropical climates. Thermal and energetic benefits of the inclusion of mechanical ventilation within the DSF cavity and electricity generation from the PV systems have been determined across a wide spectrum of Brazilian climates. Using computational simulations, DSF models with two fan configurations, placed solely at the top of the DSF and distributed along the height of the cavity, are evaluated. Annual distribution of thermal comfort acceptance and impact on energy demands from HVAC systems and contribution from the PV systems is analyzed. Results demonstrated wide variations of energy performance in relation to the climatic conditions. The ‘Cool’ climate zone presented most significant benefits from the proposed design enhancements resulting in electricity surplus. On the other hand, electricity generated from PV in the moderate climate zone can only cover about 30% of the HVAC energy consumption, whereas energy savings in the ‘hot’ zone are the lowest with only 15% of electricity contributed from the PV systems. The results of this paper contribute to the early stage of design when considering the adoption of DSF in tropical climates.

Passive Heating and Cooling Potential Strategies: A Comparison between Moderate Summers and Warm Winters Climate Zones

In this work, a comparison between different potential natural ventilation strategies used in different climate zones are investigated. As an example of moderate summer climate zone, London city has been selected, while Dubai city has been selected as a warm winter climate zone. The influence of external wind speed and pressure was studied using Autodesk Flow Design Software. Then CFD simulations have been generated inside the building using IES Virtual Environment software to study the indoor ventilation (Micro-Flow analysis) and to demonstrate the success of the adopted potential strategies in enhancing the indoor climate conditions. Hourly Analysis Program (HAP) was used to calculate the cooling/heating load of the building and to check the energy savings. The results demonstrated that comfort conditions within the interior space of the building were met during certain months of the year using passive heating/cooling strategies alone (without the need of HVAC system). HAP energy modeling results showed that the annual space cooling for Dubai model dropped from almost 58,000 kW per year to almost 42,000 kW with a total energy savings of 18.6% (including all energy consumption parameters). On the other hand, London model results showed that the annual interior space heating dropped from almost 36,000 kW to almost 28,000 kW with a total energy savings of 16.4%.

Sustainable Park Landscaping as an Approach for the Development of the Built Environment: Review and Employment

Implementing sustainable principles when landscaping parks is vital for the development of the built environment, and should take into account environmental, social, economic, and cultural aspects, in order to eliminate conflict between developmental requirements, and the need to preserve cultural and natural resources. This paper reviews the guidelines that should be considered for current and future sustainable parks in regions with a moderate climate, in order to ensure that they incorporate ecotourism, cost effective operation and maintenance, a clean environment, the promotion of renewable energy, and resource preservation. A number of parks, located in moderate climate zones, are studied in terms of aspects such as their location, topography, operation, and landscaping characteristics, to demonstrate the prevailing normative values that can be applied to sustainable park design. Prince Meshari Park, in Al-Baha city, Saudi Arabia, is employed as a case study for applying all of the guidelines proposed in this investigation, and to highlight some of their merits and limitations in terms of the current situation of the park.

Solar Radiation Forecasting for Moderate Climatic Zone

The challenge with solar energy prediction is that the solar radiation is intermittent and uncontrollable. Energy forecasting can be used to mitigate some of the challenges that arise from the uncertainty in the resource. Weather data was sourced from India Meteorological Department for Bangalore and Chennai location. This paper provides statistical approach to predict the solar power in future. Analysis was done for different predictive models; Multiple Regression Model is used as we have multiple inputs. The results indicate the prediction of solar radiation has better accuracy during higher irradiation period rather than lower irradiation period.

Prospects of use of Caltha palustris in soil plant-microbial eco-electrical biotechnology

Soil plant-microbial biosystems are a promising sustainable technology, resulting in electricity as final product. Soil microbes convert organic products of plant photosynthesis and transfer electrons through an electron transport chain onto electrodes located in soil. This article presents a study of prospects for the generation of bioelectricity by a soil plant-microbial electro-biotechnological system with Caltha palustris L. (Ranunculaceae), a marshy winter-hardy plant that develops early in the spring and is widespread in the moderate climatic zone, in clay-peat medium and with introduction of Lumbricus terrestris L. (Lumbricidae). The experiment was carried out in the wetlands of the Ukrainian Polissya and the Carpathian mountains in situ, and on the balconies and terraces of buildings to assess the possibilities of using green energy sources located directly in buildings. The electrodes were placed stationary in the soil to measure the values of bioelectric potential and current strength. We monitored the bioelectricity indices in open circle and under load using external resistors, and calculated the current density and power density, normalized to the soil surface covered by plants and electrodes. The revealed high maximal values of the bioelectric potential, 1454.1 mV, and current, 11.2 mA, and high average bioelectricity values in optimal natural conditions in wetlands in situ make C. palustris a promising component of soil plant-microbial bio-electrotechnology. We analyzed the influence of temperature and precipitation on the functioning of the soil plant-microbial biosystem. The use of thickets of C. palustris in wetlands in situ, as a stable source of plant-microbial eco-electricity in the summer, is complicated by the fact that the plant sensitively reacts to long periods of high temperature and periods of drought, which is accompanied by decrease in the level of bioelectric parameters. The cultivation of the marsh plant C. palustris as a component of electro-biosystems is possible on terraces and balconies of buildings. The cultivation of C. palustris in clay-peat soil with electrode system for production of eco-electricity on shaded balconies and terraces of buildings requires optimal irrigation, lighting, and introduction of L. terrestris into the substrate, which increase the bioelectricity values of this biotechnology.

Long-term changes in precipitation phase in Europe in cold half year

The change in precipitation phase is an important manifestation of climate change, especially in the moderate climate zone and mountain regions. We analyse changes in precipitation at 107 European stations in cold months (November–April). Stations in Czechia where both surface synoptic observations (SYNOP) reporting the precipitation phase, and temperature and precipitation data are available in sufficient quality, are used to determine the regional threshold temperature. The threshold temperature is then applied to separate solid and liquid precipitation phase in cold months at European stations in 1961–2010. If daily mean temperature is higher than the regional threshold temperature, daily precipitation amount is considered to be liquid and vice versa. The value of the regional threshold temperature is 1.1 °C. The ratio of solid to total precipitation (S/P) significantly declines over large parts of Europe. The strongest negative trend is detected in the belt stretching from the coast of northern Scandinavia through central and eastern Europe towards southern and southeastern Europe. The trend of S/P ranges from −0.2 to −0.9%·year−1 there. The average annual trend of the ratio of solid precipitation for all Europe is −0.12%·year−1. The magnitude of the trend of the ratio of solid precipitation exhibits only a minor sensitivity to the choice of the threshold temperature. A comparison with real trends, calculated for stations in Czechia, indicates that trends determined from the threshold temperature tend to be overestimated, that is, the decline of solid precipitation in Europe is even faster that what results of this study indicate.