Fogging System Research Articles

Influence of different lighting and fogging system on growth, flower yield and bud opening in Nerium (Nerium oleander)

Nerium oleander an evergreen shrub is a reputed ornamental with plentiful and long lasting flowering behaviour. But the flowers open only in the early morning hoursmaking farmers harvest the unopened flower buds between mid-night and early morning with help of head lights making them prone to reptile and other poisonous insect bites. Considering the bottlenecks in the flower bud opening, the experiment is framed to understand the influence of different light and fogging system on growth, flower yield of Nerium. The experiment was conducted in farmers field at Salem district of Tamil Nadu, India with different lighting system (red, blue, white and yellow light) and water spray (fogging system) on local Nerium variety (pink coloured flowers) replicated thrice. The results of the experiments revealed that the taller Nerium plants (230.00 cm) was observed in the treatment water spray (fog) 15 min. for every one hour which was on par (242.00 cm) with the treatment blue light (450-495 nm) for overnight + water spray (Fog) 15 min. for every one hour. The flower yield was higher (129.0 g/plant) in the treatment water spray (fog) 15 min. for every one hour. All the lighting and fogging treatment does not influence the shelf life of Nerium flowers. The higher percentage of unopened flower buds after harvest (91.6) was recorded in the treatment water spray (fog) 15 min. for every one hour. Thus, for harvesting the flower buds during the evening time, the time interval for operating the fogging system must be reoriented and anthocyanin content of flowers may be measured.

Heat Stress Mitigation with Fogging System of Anatolian Water Buffaloes

This research was carried out to investigate the possibilities of removing the heat stress that may occur in Anatolian water buffaloes with a fogging system and to determine the cooling efficiency of the system. In this context, two 24-headed groups were formed among the water buffaloes that were considered to have the same genetic similarities, were born in the same period and have the same lactation number. One group was housed under controlled shelter conditions (Shelter-I), where the ambient temperature can be controlled, and the other group was housed in existing farmer-raising conditions (Shelter-II). The same feed rations were applied to both buffalo groups. The cooling efficiency of the fogging system established in Shelter-I was between 45.6% and 85.7% positive. Temperature-Humidity Index values changed between 19.9 and 23.1 in Shelter-I and 19.5 and 26.4 in Shelter-II according to the maximum average data. According to these values, the level of stress in Shelter-II has reached very serious levels and affected the milk yield of buffaloes negatively. The corrected 305-day lactation milk yields were calculated as 1965.4 kg in Shelter-I and 1757.1 kg in Shelter-II. The differences between all data obtained for Shelter-I and Shelter-II were found statistically significant.

Performance and Techno-Economic Analysis of Inlet Fogging System Implementation in Heavy Duty Industrial Gas Turbines

This study investigates the performance and economic benefits of applying inlet fogging in a heavy duty industrial gas turbine. To achieve the aim of the study, a heavy duty industrial gas turbine engine was modelled using a gas turbine performance software, GasTurb. The modelled engine was derived from the Frame 9E class of gas turbines. Consequent upon completing the engine modelling, ambient temperature profile data obtained from a location in Niger Delta region of Nigeria were used as input into the engine model to simulate its effect on the engine performance. Inlet fogging was simulated on the industrial gas turbine by inputting a water-to-air ratio of 0.4%, to cool and reduce the air inlet temperature by 10 degree Celsius. The simulation plots show that the gas turbine performance which dropped as a result of increased ambient temperature was enhanced by the application of inlet fogging. Economic analysis shows that approximately $2.4 million profit was recorded in one year when inlet fogging system was employed.

Efficiency of cooling systems in broiler houses during hot days

ABSTRACT: This study evaluated: (1) the vulnerability of broiler houses with different cooling systems, and (2) the spatial distribution of environmental variables during hot days. Four potentially vulnerable commercial broiler houses in southern Brazil were selected according to the following parameters: absence or presence of different cooling systems, broilers older than 28 days, and outside air dry-bulb temperature over 30°C. Broiler house vulnerability was classified according to the cooling and mechanical ventilation system: cellulose pad cooling (CPC), sprinkling (SPK), fogging (FOG), and mechanical ventilation without evaporative cooling system (VTL). The air dry-bulb temperature (Tdb, °C) and relative humidity (RH, %) were recorded every 10 min. For each broiler house, we evaluated: (1) relative cooling efficiency (RCE) and (2) inside spatial distribution of microclimate variables using a geostatistical technique. The CPC and SPK did not differ (P<0.05) in RCE (81.6% and 80.7%, respectively), but both differed from FOG (23.8%) and VLT (1.87%) systems. The highest variations in indoor Tdb were recorded in the FOG (7 °C), followed by the SPK (4 °C) and CPC (3 °C). In the CPC, there was an increase in RH from the middle to the end of the broiler house near the exhaust fans. In conclusion, the relative cooling efficiency and the inside spatial distributions of environmental variables in the broiler houses were influenced by the existing cooling system.

Numerical evaluation of the motion of fogging flow along the inlet duct of gas turbine engines

Computational fluid dynamic analysis of inlet duct fogging system was carried out to understand the characteristics flow of nozzles spray along the air inlet duct channel of Alstom GT13E2 gas turbine, the numerical work is validated using wind tunnel experimental data of previous study. Flow resistance on the nozzle were studied at specified reference locations. The results obtained have shown that, fogging spray possesses significant effects on mass flow rate due transfer of heat of evaporation caused by air to the liquid droplets in the inlet duct, which greatly influence the performance of the compressor and turbine. An adequately space between the nozzles array and compressor bell mouth produces mass flow rate evaporability up to 87.63% and temperature difference drop by roughly 6°C. The pressure distribution becomes uniformly and squarely distributed when positioned at least 2.0 m away from the nozzle array. The current research offers an inclusive coverage on the droplets evaporative cooling effects, air flow resistance through pressure drop and their effects on the compressor performances, it is our desire that the work will be of added benefit to the gas turbine engine designers.

Use of Different Cooling Methods in Pig Facilities to Alleviate the Effects of Heat Stress-A Review.

Simple SummaryHeat stress triggers behavioural and physiological response and thus negatively affects productivity in livestock. Among farm species, pigs are especially susceptible to exposure to high air temperatures. The evaporative pad cooling system, high pressure fogging, sprinkling as well as elevating of air velocity and floor cooling are the methods most often used in pig facilities to alleviate the effects of heat stress. This article mainly discusses issues linked with the effectiveness of the various cooling methods on improving the indices of animal welfare.An increase in the frequency of hot periods, which has been observed over the past decades, determines the novel approach to livestock facilities improvement. The effects of heat stress are revealed in disorders in physiological processes, impaired immunity, changes in behaviour and decreases in animal production, thus implementation of cooling technologies is a key factor for alleviating these negative consequences. In pig facilities, various cooling methods have been implemented. Air temperature may be decreased by using adiabatic cooling technology such as a high-pressure fogging system or evaporative pads. In modern-type buildings large-surface evaporative pads may support a tunnel ventilation system. Currently a lot of attention has also been paid to developing energy- and water-saving cooling methods, using for example an earth-air or earth-to-water heat exchanger. The pigs’ skin surface may be cooled by using sprinkling nozzles, high-velocity air stream or conductive cooling pads. The effectiveness of these technologies is discussed in this article, taking into consideration the indicators of animal welfare such as respiratory rate, skin surface and body core temperature, performance parameters and behavioural changes.

Efficacy of three disinfectant formulations and a hydrogen peroxide/silver fogging system on surfaces experimentally inoculated with meticillin-resistant Staphylococcus pseudintermedius.

Effective environmental disinfection is necessary to prevent nosocomial infections from meticillin-resistant Staphylococcus pseudintermedius (MRSP). However, there are currently no commercial disinfectant sprays or fogging systems with label claims against MRSP. To evaluate the efficacy of a quaternary ammonium product (QAC), an accelerated hydrogen peroxide product (AHP), a hydrogen peroxide and silver product (HAL), and a hydrogen peroxide and silver fogging system (FOG) against MRSP. Sterile plastic surfaces inoculated with MRSP were treated with 200µL of QAC, AHP or HAL for the recommended contact times. For FOG, inoculated samples were placed in eight positions within a sealed room before fogging for the recommended contact time. Post-treatment bacterial counts were compared to untreated positive controls. Sterile uninoculated surfaces served as negative controls. Least-squares mean reduction (log10 ) in colony forming units (cfu) was 3.55 log10 for QAC (P<0.0001), 3.60 log10 for AHP (P<0.0001), 1.66 log10 for HAL (P<0.0001) and 0.32 log10 for FOG (P=0.004). QAC, AHP and HAL reduced MRSP cfu by 99.97%, 99.98% and 97.81%, respectively. FOG reduced cfu by 52.14%. QAC and AHP effectively disinfected surfaces inoculated with MRSP. Although HAL provided lower MRSP reduction, it may be considered clinically acceptable. FOG as a sole means of MRSP disinfection was not supported yet may have utility as an adjunctive disinfectant in clinical areas with bacterial densities lower than our experimental inoculum.

Control of greenhouse-air energy and vapor pressure deficit with heating, variable fogging rates and variable vent configurations: Simulated effectiveness under varied outside climates

Climate in greenhouses is continuously influenced by the outside environmental conditions. Outside conditions are always variable, especially in locations with extreme climates. Under non-extreme climates, greenhouses equipped with natural ventilation systems coupled with on–off controllers may be sufficient to effectively maintain appropriate climate conditions for plant growth. However, additional and flexible climate control systems, such as variable frequency drive (VFD) controllers, may be needed under extreme environments. In this study, the performance of a greenhouse climate control strategy, which considers plant transpiration, includes heating, operates variable vent configurations and a fogging system on a VFD basis, was tested by computer simulations. The strategy uses a set point of air specific enthalpy (55.8 kJ kg−1) to control the heaters and vents while a set point of Vapor Pressure Deficit (VPD) of 1.0 kPa is used to control the fogging system. Simulations were performed for two locations with different climates to test the strategy’s capabilities. Set points were effectively maintained whenever cooling demands existed in the greenhouse. For that, the crop played a key role by adding to the atmosphere on average 55.14 and 84.53% of the water vapor by means of plant transpiration for the first and second locations, respectively. When demands for heating existed, the set points were maintained whenever it was psychrometrically possible. When the outside air is at high humidity levels, the set points cannot be achieved under this approach. Under such conditions, the set points may be continuously and simultaneously kept if a dehumidification action is added to the strategy.

Comparison of gas turbine inlet air cooling systems for several climates in Iran using energy, exergy, economic, and environmental (4E) analyses

The effects are investigated of using absorption chiller, heat pump, and inlet fogging systems for cooling the inlet air of a gas turbine power plant for four cities in Iran representative of different climatic conditions, namely Yazd (hot–arid), Bandar Abbas (hot–humid), Ardabil (cold-humid) and Sari (humid subtropical). Gas turbine functional parameters, quantities of emitted pollutants, prices of generated electricity and capital cost payback periods are determined. The rates of pollutants produced and fuel consumption are considered per unit of electricity generated. The results show that the best cooling system for cities with hot climates is the absorption chiller; it improves gas turbine net power by 18% in Bandar Abbas and 14% in Yazd, the energy efficiency by 5.8% in Bandar Abbas and 5.5% in Yazd, and the exergy efficiency by 2.5% in Bandar Abbas and 1.5% in Yazd. Inlet air cooling reduces NOx pollutant emissions by 60% in Bandar Abbas and 53% in Yazd and reduces electricity generated costs by 6.5% and 6.0% in Bandar Abbas and Yazd respectively. The inlet fogging system performs well only in arid regions. The most appropriate type of cooling system must be selected based on specific objectives (such as increasing power or reducing fuel consumption or reducing pollutants). In cold regions such as Ardabil, where cooling system is used only for a limited period, the heat pump system is suitable because of its low initial investment cost.

Empirical modelling of temperature in fogging greenhouse

The objective of this article is to evaluate the inside temperature of greenhouse and efficiency of fogging system under the influence of solar power. A 50% off sun shading roof was selected to test in this study. Testing is divided to 2 cases. Case I Measuring all of parameters without operate the fogging system and ventilation between 9.00 a.m. to 5.00 p.m. (Thailand’s time zone). Case II Measuring all of parameters with a fogging system that was controlled the relative humidity below 80% all day. The results show that the highest temperature in greenhouse is 50.13oC (no fogging and ventilation). the developed empirical model has an error 6.33% between numerical results and measured air temperature. In case of neglected solar power, the model showed that the fogging system can reduce the temperature in greenhouse in range of 7.05°C (18.44%) and the efficiency of fogging system is quite high (value is 57.36%). The important factor that influents on the air temperature in greenhouse is solar power. If we need to control the atmosphere in greenhouse by fogging system than the reduction of solar power is the most important controlling factor.

Application with initiative to replace common insect fuel for fogging system with biodiesel

The project addressed the application of biodiesel as a fuel in replacing the petroleum-based liquid carrier in common fogging system. In controlling the population of larvae and adult mosquito using chemical pesticide spraying through fogging method, the dilution rate based on the efficient mixing of pesticide and biodiesel is yet to be investigated. A simulation field trial was conducted indoor in a visible container with the designed dimension of 50 cm × 50 cm × 50 cm with the method of fogging was adapted from the principle of thermal fogger. The biodiesel was produced through the transesterification reaction of palm oil with methanol using hydrotalcite as catalysts. To evaluate the larvicidal and adulticidal mortality, dilution of pesticide which is Sumithion L-40 into biodiesel as liquid carrier is varied. The 5 ml pesticide-carrier mixture with the dilution ratio of 1:9, 3:7 and 5:5 were used and dispersed into the ambient in the form of fog. After several tests, it can be deduced that the most effective dilution ratio for against larvae is 1:9 and adult mosquito is 5:5. The larvae mortality rate achieved 100% at the duration of 117 min due to effective settlement of the spraying droplet of formulation mixture on exposed water. The result also proven that, biodiesel as liquid carrier capable to overcome the solubility problem encountered by the conventional petroleum-based carrier. The adult mosquito needs shorter knockdown time with the higher dosage of pesticide. Sumithion L-40 consists of two active ingredients which are tetramethrin and fenitrothion that provide quick knockdown and residual effect especially to adult mosquito.

Effect of Ultrasonic Atomizer on the Yield and Yield Components of Tomato Grown in a Vertical Aeroponic Planting System

Aeroponic planting is proved to be the one of the most efficient growing environments for many vegetable crops. In this technique, plants are cultivated in absence of soil and the required nutrients are directly supplied to the roots through a fogging system. In modern sprayers, water is atomized by means of ultrasound waves. The aim of the present study was to investigate the effect of ultrasound waves on the nutrient solution and on yield and some yield components of tomato grown in a vertical aeroponic planting system. The investigation was conducted using a 3×3 factorial experiment based on a completely randomized design. The considered factors were ultrasonic frequency at three levels of 50 kHz, 107 kHz and 2.1 MHz and the fogging duration at three levels of 10, 15 and 20 min. The results indicated that, at frequency of 50 MHz, the nutrient solution had the lowest EC equivalent while the pH of the nutrient solution reached its highest value at 2.1 MHz. Generally, both EC and pH value of the nutrient solution were elevated by increase in the wave frequency, but they did not show a definite trend by changes in fogging duration. The ANOVA indicated that the interaction effect of the ultrasound frequency and fogging period had significant effect on the plant height, root weight and length, fruit weight, fruit length, plant yield and system performance. In general, the measured yield components decreased as frequency of the waves increased and the best results were obtained at 50 kHz frequency and 15 min fogging period.

Augmentation of gas turbine performance using integrated EAHE and Fogging Inlet Air Cooling System

In the present work, new hybrid cooling system is demonstrated and compared with other configurations of gas turbine inlet air-cooling systems. The cooling configurations include the earth-air heat exchanger, fogging and a new hybrid cooling system. Three models are developed, the first is for prediction of the cooling potential of the fogging system and the second is based on the transient one-dimensional heat transfer modeling which is used to describe the thermal behavior of the earth-air heat exchanger. The third model is a combination of earth-air heat exchanger and fogging cooling system as a new hybrid cooling system. New Damietta power plant located in the coastal region in Egypt (Latitude = 31.4 and Longitude = 31.7) is applied as a case study. A comparison between the effects of the three air cooling techniques on the gas turbine performance was performed. It is observed that the hybrid system is superior to the unitary systems as it is capable of boosting the average annual energy by 9.8% versus 8 and 6.6% for fogging and earth-air heat exchanger system; respectively. In addition, the hybrid system reduces the water consumption by 50% compared to the fogging system. Moreover, the hybrid cooling system is the most efficient method in the areas where the temperature is over 30°C and the relative humidity is less than 60%.

Gasification enhancement and tar reduction using air fogging system in a double walled downdraft biomass gasifier

Air-blown gasifier suffers from lower heating value of producer gas (PG) compared to steam gasification, but at the expense of the addition of steam boiler for the latter. The performance of an air-blown double walled downdraft biomass gasifier was characterized experimentally. Air fogging unit was added to the annulus of the gasifier allowing for superheated steam to be generated as additional oxidizer. Steam-to-biomass (S/B) ratio has been introduced to investigate the optimum amount of injected water needed to produce the optimum quality of PG. Comparisons were made on the composition and heating value of PG with and without water injection which were analysed and calculated with the aid of gas chromatograph. Highest heating value of PG was 4.72 MJ/Nm3 at S/B ratio of 0.2 which corresponded to about 10% increment. Various S/B ratios were investigated in this study in the range of 0.1–0.3. However, as S/B ratio exceeded 0.25, it resulted adversely to the quality of PG. The effect of water injection on tar contamination in PG was also investigated. Tar reduction was proportional to the amount of the injected water resulting in about 8% reduction at maximum S/B ratio corresponding to 0.65 g/m3 tar yield.

Sensitivity Analysis on the Effect of D32 and Dv90 on the Evaporation Efficiency of Gas Turbine Inlet Fogging for Power Augmentation

Gas turbine output is strongly dependent on the ambient air temperature. This decrease usually occurs in the hot afternoon during the peak demand for power. One way to counter this drop in output is to cool the inlet air using one of the available cooling technologies such as the inlet fog cooling of gas turbine engines for power augmentation. This technology is well established with over 1000 fogging systems installed all around the world on gas turbines of various makes and sizes ranging from 5 MW to 250 MW. Two types of statistical droplet diameters are used to characterize the droplet sizes from nozzles used in the fogging systems, namely D32 (Sauter mean diameter) (SMD) and Dv90 (diameter for which 90% of the water volume in the spray is less than or equal to). This paper will show the importance of each diameter on the performance of fogging systems. For this purpose, a heat and mass transfer theoretical model is developed to analyze the dynamics of evaporation of fog droplets. The model will quantify the evaporative efficiency of fog droplets for different D32 and Dv90 values derived from experimentally measured droplet size distributions at two typical ambient psychrometric conditions: hot and dry, and cold and humid.

Applicability of Inlet Air Fogging to Marine Gas Turbine

Abstract The dependency of marine gas turbine on the ambient temperature leads to a decrease of the gas turbine power output in arid areas. Very often gas turbine power output demand is high and the power margins originally designed into the driver, has been exhausted. In such circumstances the inlet air fogging is an effective compensation of gas turbine power. In this paper an analysis of inlet air fogging applicability to marine gas turbine has been conducted. Different areas of ship’s voyage have been taken into account. The use of inlet air fogging in marine gas turbine must be evaluated on the basis of turbine characteristics, climate profile of ship’s voyage, and expectations of gas turbine power augmentation. The authors expect that the considerations provide useful guidance for users of marine gas turbines to decide the feasibility of installing an inlet air fogging system.

Mini-incubators improve the adventitious rooting performance of Corymbia and Eucalyptus microcuttings according to the environment in which they are conditioned.

We addressed a major challenge in the in vitro clonal propagation of Corymbia citriodora, Eucalyptus urophylla and E. benthamii by using an ex vitro adventitious rooting strategy in a mini-incubator. Mini-incubators were placed in four environments for rooting. A shade house with no fogging system and a greenhouse with no ventilation but with a fogging environment had the best performance in terms of rooting, root growth and survival of microcuttings. Daily recording of the temperature within each mini-incubator in each environment allowed the verification of negative correlations between the maximum average temperature and the survival, adventitious rooting and root growth. The ideal maximum air temperature for the efficient production of clonal plants was 28.4°C (± 5.5°C), and the minimum was 20.3°C (± 6.2°C). E. benthamii was more sensitive to higher temperatures than C. citriodora and E. urophylla. Nevertheless, placing mini-incubators in the shade house with no fogging system resulted in a stable and uniform performance among the three species, with 100.0% survival and 81.4% rooting. Histological sections of the adventitious roots revealed connection with the stem vascular cambium. Therefore, our experimental system demonstrated the potential of mini-incubators coupled with the proper environment to optimize the adventitious rooting performance of microcuttings.

Effect of display case cooling technologies on shelf-life of beef and chicken

Shelf-life is defined as the time a food product retains its desired sensory, chemical, and physical characteristics while also remaining safe for consumption. Bacteria associated with meat spoilage produce off-odors and flavors, tissue discoloration, gas, and slime. The objectives of this study were, 1) to determine the effect of refrigerated-display-case type on the shelf-life and microbial load of the natural flora found on beef steak and chicken breasts and, 2) to evaluate the effect of gravity coil conductive cooling vs. complete conductive cooling on the growth of Escherichia coli K12 artificially inoculated onto beef steak under abusive conditions. In Study 1, beef steak and chicken breasts were placed for 8 or 5 days, respectively, in a conduction cooling gravity assist service case, gravity coil service case with partial conduction coil base deck, gravity coil service case with serpentine assist, or blower coil service case with an additional fogging system. Mesophilic bacteria, Pseudomonas spp. and psychrotrophic bacterial counts on meat surfaces, and meat color, internal meat temperature, case temperature and case relative humidity were determined daily. In Study 2, two of the four types of display case ̶ the complete conductive cooling and gravity-coil conduction cooling systems ̶ were chosen to evaluate microbial growth on beef steak due to novel conductive cooling technologies. Temperature and weight loss, aerobic plate counts and viable E. coli colony-forming-units on the beef steaks were determined daily. In study 1, the warmest display ambient air temperature was found in the gravity coil service case with partial conduction coil base deck (PCC). The coldest tissue temperatures were observed for steaks and chicken breasts placed in the conduction cooling gravity assist service display case. The lowest RH also tended to occur in the PCC case. Overall, the type of retail display case had no effect on the growth of mesophilic and psychrotrophic bacteria or Pseudomonas on both steaks and chicken breasts. In study 2, the initial numbers of viable E. coli K12 on inoculated steaks were low and remained low through 7 days storage, regardless of display case. The novel conduction cooling gravity assist service display case used in this study has the greatest potential for extending shelf-life due to lower overall tissue temperatures and reduced water loss from meat products held in this case during high traffic and abusive retail conditions.

Impact of Fogging System on Thermal Comfort of Lactating Sows

The aim of this study was to evaluate the effectiveness of a simple fogging system on the microclimate of a farrowing room and the sows’ welfare, which was analyzed through physiological indicators such as respiration rate, and rectal and skin surface temperature. Of 42 lactating sows, 21 were housed in a section (section I) of the farrowing room with a high-pressure fogging system, while the other group (n = 21) were housed without any cooling treatment (section II). Significant differences were found between mean values of microclimatic parameters. The air temperature in section I with active cooling was 2.1°C (p = 0.01) lower than in section II; however, the cooling induced a significant (p = 0.01) increase (18.6%) in air relative humidity. The mean temperature-humidity index (THI) was 0.8 lower (p = 0.05) in the cooled section. The fogging system had a significant impact on the reduction of respiration rate. Rectal and skin surface temperatures were at similar levels in both groups of sows. Based on this study, future research is needed to continue the development of this system as well as new technologies that would be applicable for the climate conditions of central and eastern Europe. Keywords: Animal welfare, Animal housing, Cooling.

Mitigating heat stress of dairy cows bred in a free-stall barn by sprinkler systems coupled with forced ventilation

This paper presents the results of a research study which had the objective of investigating the effect of a sprinkler system coupled with forced ventilation on the heat stress of dairy cows bred in a free stall barn without paddock. To this aim, an experiment was carried out inside a free-stall dairy house equipped with two different cooling systems: a fogging system associated with forced ventilation in the resting area and a sprinkler system associated with forced ventilation in the feeding alley. The experiment regarded two adjacent pens of the barn and was constituted by three different trials carried out in the following periods: 27th June – 7th July (P1), 25th July – 4th August (P2), 24th August – 3rd September (P3). The experimental protocol of each trial required that the treatment group was housed in one pen where the two cooling systems were always activated following an established timetable, whereas the control group was housed in the other pen, where the sprinkler system associated with forced ventilation was always deactivated. Climatic parameters were measured inside each pen of the barn and outside. Then, thermal humidity index (THI) was calculated. Rectal temperature and respiration rate of a sample of dairy cows were monitored each day during the three periods considered (P1, P2 and P3). During the three trials the cows of both groups were subjected to climatic conditions that resulted in average daily THI values between 72.8 and 74.7, corresponding to mild or moderate heat stress. However, during daytime, air temperature and relative humidity reached values corresponding to a severe heat stress, as attested by the maximum THI values that were higher than or very close to 80. Furthermore, it was observed that the sprinklers do not influence the microclimatic conditions. However, the physiological parameters values of the treatment group were always significantly lower than the corresponding ones of the control group. Specifically, the system especially influenced the respiration rate that, in the treatment group, was close to 50 breath/min, while in the control group it reached 70 breath/min. The sprinkler system had more limited effects on rectal temperature that, however, in the treatment group was significantly lower than in the control group (38.7°C to 38.8°C vs 39.1°C 39.4°C) in all the three periods of the experiment. These results show that the sprinkler system could be useful to mitigate heat stress in dairy cows.