Dry Bulb Research Articles

A modified efficiency-NTU method (m-ε-NTU) for calculating air coolers in dehumidifying or frost conditions. Part I

In this part of the article, a literary review of the methods of stationary calculations of air coolers operating in dehumidifying or frost conditions is carried out. The approaches used at the moment are reviewed, namely: dehumidification coefficient method; logarithmic enthalpy difference method (LMED); equivalent dry-bulb temperature method (EDT); as well as -NTU method (efficiency number of heat transfer units) for calculating counterflow chilled water coils. Their main differences are shown and the key expressions used in them are given. A comparison of the advantages and disadvantages of the considered methods showed the rationality of using -NTU approach due to the possibility of its application for both design and verification calculations of heat exchangers. Since the classical -NTU method is not directly applicable to dehumidifying or frost conditions, it becomes necessary to adapt it to the calculations of air coolers of all types (both counterflow and parallel-flow air coolers without phase transition of the cooling fluid, and for cases with its phase transition) to correctly describe the effect of the above processes on heat exchange.

Effect of Inlet Air Humidity Control on a Novel Indirect Condensative Cooling Performances in Achieving Air Thermal Comfort

The objective of this research is to investigate the effect of controlling inlet air relative humidity on the performance of solid dry pad based indirect condensative cooling (SDP-ICC) system, in an effort to have a better air thermal comfort. The main evaporative cooling parameter such as cooling efficiency, cooling capacity, and temperature drop, condensation rate and energy efficiency ratio would be observed, together with the final dry and wet bulb air temperature and relative humidity in respect to reach the standard air thermal comfort. During the experiment test, the inlet air would be heated respectively using 1.0 kW, 1.5 kW and 2.0 kW heater in a climate chamber before it passed through to the solid dry pad, to be cooled indirect condensatively. The air velocity would be set on 11.3 m3/. The test results indicate that to achieve an air thermal comfort significantly in the evaporative and or condensative cooling system, the air should need to be treated with more than one thermal process, rather than cooling only. In this research, the SDP-ICC has only achieved the air thermal comfort in respect to its relative humidity of 67.3%, 55.65% and 44.3% respectively for heating capacity of 1.0 kW, 1.5 kW and 2.0 kW. The highest SDP-ICC cooling performance has been achieved on 1.5 kW heating capacity, in which it has reached 1.9 kW, 1.83, 3.4oC and 0.237 m3/hr respectively for cooling capacity, energy efficiency ratio, temperature drop and condensation rate. It can be concluded that by heating the inlet air relative humidity in evaporative and or condensative cooling system, it can be resulted the product air which has met the standard air thermal comfort.

Optimal heat stress metric for modelling heat-related mortality varies from country to country.

Combined heat and humidity is frequently described as the main driver of human heat-related mortality, more so than dry-bulb temperature alone. While based on physiological thinking, this assumption has not been robustly supported by epidemiological evidence. By performing the first systematic comparison of eight heat stress metrics (i.e., temperature combined with humidity and other climate variables) with warm-season mortality, in 604 locations over 39 countries, we find that the optimal metric for modelling mortality varies from country to country. Temperature metrics with no or little humidity modification associates best with mortality in ~40% of the studied countries. Apparent temperature (combined temperature, humidity and wind speed) dominates in another 40% of countries. There is no obvious climate grouping in these results. We recommend, where possible, that researchers use the optimal metric for each country. However, dry-bulb temperature performs similarly to humidity-based heat stress metrics in estimating heat-related mortality in present-day climate.

The diurnal variation of wet bulb temperatures and exceedance of physiological thresholds relevant to human health in South Asia

Extreme heat is increasingly being acknowledged as a serious hazard to human health, through a combination of physiological responses to heat, expressed as dry and wet bulb temperatures, and personal factors. Here we present an analysis of the diurnal variability of dry and wet bulb temperatures using station data in South Asia during both regular and heatwave days. We find that diurnal cycles differ, with the daily maximum wet bulb temperature occurring several hours after the daily maximum dry bulb temperature. Using radiosonde profiles, we show that the timing and amplitude of the diurnal variability of wet bulb temperature can be explained by changes in boundary layer depths and water content. Physiological thresholds for uncompensable heat stress were exceeded even in the evenings, many hours after dry bulb temperature peaks. Cumulative exceedances occurred in 105 instances, corresponding to at least 300 hours of exposure to uncompensable heat stress in South Asia between 1995 and 2020. We conclude that physiologically relevant thresholds provide a more robust way to estimate health impacts, and that wet bulb temperature alone is insufficient as an indicator of hazardous heat.

Investigation of thermal comfort conditions by heat pump Hybridized with phase change Material-based solar desiccant cooling system

In response to the challenge of providing energy-efficient thermal comfort in hot and high-humidity cities, this study investigates innovative cooling systems that can mitigate issues of overcooling and excessive energy consumption seen in conventional air conditioning systems. Also, conventional cooling systems contribute to global warming by emitting high levels of greenhouse gases. In this research, two systems Phase Change Material (PCM)-based Solar Desiccant Cooling System (PSDC) and Heat Pump Hybridized with a PCM-based Solar Desiccant Cooling System (HP-PSDC) were investigated for a typical residential house located in Doha (Qatar), Vancouver and Toronto (Canada), and Bangkok (Thailand). According to the findings, the PSDC system provides thermal comfort conditions in Vancouver and Toronto with COP of 1.05 and 1.44, respectively. While in Doha and Bangkok, the innovative system that is HP-PSDC system has better performance when the COP (Coefficient of Performance) of the former is 4.98 and the latter is 4.5. The novelty of this work lies in the approach to balancing thermal comfort conditions with energy consumption. Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) were determined to set design criteria for the selection of the proper system based on the weather conditions of each city by using Design of Experiment (DOE) analysis. According to DOE, the dry bulb temperature, the wet bulb temperature, and the absolute humidity of the ambient air are three key characteristics that must be considered when choosing the appropriate system to provide thermal comfort conditions. It was found that if the wet bulb temperature of the building location is more than 21.5 °C, utilizing the HP-PSDC system can guarantee thermal comfort condition. However, for wet bulb temperatures less than 18.5 °C, the PSDC system is recommended. This research presents implications for the design of sustainable cooling systems, offering energy efficiency improvements and climate-specific system selection guidelines.

Attraction of Tetranychus urticae to garlic treated with chlorfenapyr to control dry bulb mite, Aceria tulipae

Attraction of Tetranychus urticae to garlic treated with chlorfenapyr to control dry bulb mite, Aceria tulipae

Evaluation of Body Surface Temperature in Pigs Using Geostatistics

This paper explores the potential of infrared thermography and geostatistics in animal production and presents the results of the application of the combination of these techniques, contributing significantly to efforts to obtain animals’ responses to the environments in which they are located and thereby ensuring improvements in productivity and animal welfare. The objective was to verify the variability in surface temperature in pigs submitted to different climate control systems using geostatistics. Three growing animals per stall were selected. Dry bulb temperature (Tbd, °C), relative humidity (RH, %) and thermal images were recorded at 08:00 and 12:00 h. To analyze the data, semivariograms were made, the theoretical model was validated and kriging maps were constructed. The mean temperature of the pigs in the pen with adiabatic evaporative cooling (AEC) ranged from 32.40 to 36.25 °C; for the pigs in the forced ventilation (FV) pen, the range of variation was from 32.51 to 36.81 °C. In the control group (Con), with natural ventilation, the average temperature was 37.51 to 38.45 °C. The geostatistical analysis provided a mathematical model capable of illustrating the variation in temperature in the caudal–dorsal regions of the pigs according to the environments to which the animals were subjected.

Experimental study on the operating performance of the air source heat pump (ASHP) with variable outdoor airflow rate under the standard frosting condition

Frosting is a common phenomenon of the ASHP under the heating mode in winter, and the outdoor air flow rate flowing through the evaporator of the ASHP was always thought to be a major contributor. In order to validate its contribution, effects of outdoor fan airflow rate on the performance of air source heat pumps (ASHPs) were investigated under the winter heating condition. The experiment was conducted in a laboratory at the standard 2 °C air dry bulb temperature (DB)/ 1 °C air wet bulb temperature (WB) frosting condition, which enabled the analysis of the operating performance, frosting performance, and heating performance of the ASHP unit by changing the airflow rate of the outdoor fan. Results showed that as the airflow rate of the outdoor fan reduced from 100% to 36%, the operating performance decline and the elevated frosting-defrosting loss were observed. Meanwhile, both the frosting rate and the operating efficiency during frosting-defrosting cycles showed an increasing trend then followed by decreasing tendency. The maximum frosting rate and operating efficiency were 0.92 g/m2.min and 2.92, respectively, which were observed at 74% airflow rate of the outdoor fan of the ASHP unit. The observation implied the existence of the “minimum frosting suppression airflow rate”. At 36% airflow rate of the outdoor fan of the ASHP unit, however, the performance of the ASHP unit was attenuated greatly, with the frosting-defrosting efficiency loss coefficient of 0.47, the heating capacity and COP reduction by 51.5 and 38.8%, respectively. These findings provided significant references to the optimization of ASHPs performance with variable airflow rate of the outdoor fan under frosting conditions.

Experimental evaluation of a water spray system for semi-outdoor spaces: Analysis of the effect of the operational parameters

As a consequence of climate change, urban overheating has increased in all the cities of the world during the last decades. It is therefore paramount to counteract such effect by promoting the use of effective solutions to mitigate overheating at a micro-scale level. In this work, a modular experimental setup based on a water spray system was designed, realized and tested to evaluate its thermohygrometric performance in semi-outdoor spaces such as bus/train/taxi stops, street resting stations and corner shops. The setup allows to vary three operational parameters: (a) the height of the nozzles from the ground; (b) the presence of an upper shielding to reduce the impact of solar radiation; (c) the presence of a side shielding to reduce the impact of wind speed. The combination of the operational parameters allowed to evaluate the performance of five configurations for the water spray system. Several performance indexes were calculated to assess the impact of each operational parameter. It was found that the best configuration guarantees a −20% reduction of dry-bulb temperature, and the minimum specific water and electricity consumptions of the system are 0.020L/m2 and 0.150Wh/m2, respectively. Also, the presence of the side shielding is the parameter that mostly influences the performance of the system, followed by the height of the nozzles, while the presence of the upper shielding has a minor effect. These operational parameters, however, increase relative humidity inside the nebulization volume; it is therefore important to verify if undesired wet conditions are reached.

Processing algorithm of weekly records of the Roztochia landscape-geophysical station thermograph М-16АН as a response source of air temperature data

Formulation of the problem. During the database processing of the Roztochia landscape-geophysical station (RLGS), located in the village of Bryukhovychi, Lviv, an air temperature data gap for 1990–1991 was found. The task of the research was to find those sources about air temperature at RLGS, which would allow us to fill in the gaps during the night hours when, unfortunately, observers did not make measurements. Problems of further research. In comparison with the method adopted in Ukraine for processing weekly thermograph tapes, in this study, it is proposed to correct the air temperature value during their processing, compensating for accelerated or slowed rotation of the weekly thermograph drum. It is suggested to use only those dry bulb measurements carried out on days with cloudy or rainy weather. The purpose. The main goal was to find an algorithm for processing weekly thermograph tapes under the conditions of a partial absence of temperature measurements using a dry thermometer by an observer to fill in the gaps regarding night air temperature data. Research methods. The air temperature values falling during the measurement period were read from the thermograph tapes, and an electronic table was formed. The temperature values (difference estimation) were compared with the corresponding ones recorded in the "Books" of KM-1. At the same time, it was necessary to make two new corrections. The first correction will be made along the ordinate axis, changing the value of the temperature recorded by the thermograph compared to the values of the temperature measured by the dry thermometer. The second correction was made along the abscissa axis, compensating for the drum's slowed down or accelerated rotation. Presentation of the main research material. A brief description of the proposed algorithm for thermograph tape processing is as follows. In the spreadsheet, in separate columns, we record the temperature values during the observation periods: a) by dry thermometer and b) by thermograph at the points corresponding to the observation periods. Subtracting columns (a) and (b) values, we determine those dry bulb temperature values suitable for calculating corrections. We reject too significant differences that occur during rapid temperature changes. Next, we look for points on the thermograph tape that serve as time benchmarks (the starting and ending points of the temperature curve and the places where the observer draws vertical lines). These temperature values will form column (c). It will additionally include the temperature values obtained by reading the temperature from the tape for rainy and/or overcast days for points whose localization is corrected for time. The difference between column (a) and column (c) will give the temperature correction for several observation periods on each weekly strip taken separately. The last step is the linear interpolation of temperature corrections between neighbouring points of intermediate observation periods. Practical value. The proposed algorithm may help eliminate gaps in temperature data at other observation points, where the thermograph served as a backup device for recording air temperature. Research results. The measurements that fall on rainy and overcast weather are best suited for calculating thermograph corrections when air temperature changes slow down. It is necessary to identify benchmark points of time fixation, to which the observer must add the moments of putting on and removing the tape from the drum.

Evaluation of the effect of the indoor environment on the physiological responses of early-gestation sows in a commercial house in China.

The environment influences the sow's health and physiology during gestation. This study was conducted to evaluate indoor environmental parameters and physiological responses of early-gestation sows and investigate the possible methods for assessing the thermal environment in commercial houses. A total of 20 early-gestation sows (commercial purebred Yorkshire) with an average body weight of 193.20 ± 3.62 kg were used for this study in winter, spring, summer, and autumn. The indoor environment parameters comprising dry-bulb temperature (Tdb), relative humidity (RH), and carbon dioxide (CO2) were recorded in 30-min intervals. Physiological parameters including heart rate (HR) and respiration rate (RR) of sows were also measured every 30 min. Wet-bulb temperature (Twb) was calculated using Tdb, RH and atmospheric pressure was recorded at a nearby weather station. The average indoor Tdb and RH were 12.98 ± 2.03°C and 80.4 ± 6.4% in winter, 18.98 ± 2.68°C and 74.4 ± 9.0% in spring, 27.49 ± 2.05°C and 90.6 ± 6.4% in summer, and 17.10 ± 2.72°C and 64.5 ± 10.9% in autumn. A higher average concentration of CO2 was observed in winter (1,493 ± 578 mg/m3) than in spring (1,299 ± 489 mg/m3), autumn (1,269 ± 229 mg/m3), and summer (702 ± 128 mg/m3). Compared with the HR and RR in the optimum environment, high RH in the house led to a significant decrease in both HR and RR (P < 0.05). In addition, a significant decline in HR was also obtained at high temperatures (P < 0.05). A temperature humidity index (THI), THI = 0.82 × Tdb + 0.18 × Twb, was determined for early-gestation sows, and the THI thresholds were 25.6 for HR. The variation in THI in summer showed that heat stress still occurred under the pad-fan cooling system. This study demonstrated the critical significance of considering physiological responses of early-gestation sows in commercial houses and THI thresholds. We recommend that much more cooling measures should be taken for early-gestation sows in summer.

Pad type impact on the economical direct- evaporative air cooler efficiency

ABSTRACT Theoretical and experimental investigations were performed to study the impact of four pads in series on the thermal performance of an economical evaporative air cooler that works at a low voltage (12 Volts). Straw and cardboard pads were studied. The studied parameters were dry bulb temperature, the dry bulb temperature difference between inlet and outlet air, cooling efficiency, and the total heat transfer rate. Three draft fan speeds were considered, i.e. 2.8, 3.5, and 4.7 m/s. The results showed that adding multiple pads in series had an insignificant impact on the evaporative cooler thermal performance compared to one pad. The straw pads’ cooling efficiency at 2.8 m/s was lower than that of the cardboard, i.e. 91.4% and 93.1%, respectively. Also, it was found that the velocity of the air passing through the cooler significantly impacted the cooling efficiency. The theoretical results for the lowest speed of 2.8 m/s showed an increase in the cooling efficiency of the cardboard pad by 46.6% compared to the speed of 4.7 m/s due to a long time for heat transfer. Therefore, the best air velocity entering the cooled space was 2.8 m/s.

Performance Evaluation and Optimum Design of Ventilation Roofs with Different Positions of Shape-Stabilized PCM

Environmental pollution and energy shortages have become increasingly prominent. Building energy conservation is an important part of a low-carbon strategy. Integrating phase change material (PCM) into a building’s roof is effective in altering the space cooling load, however less effective in reducing it. To reduce the cooling load, a novel ventilation roof with shape-stabilized PCM (VRSP) is introduced. The mechanical ventilation is used at night by embedding ducts in the roof to remove the solidification heat of the PCM. To identify the best position of PCM and an optimum design, the thermal performances of three kinds of VRSPs were compared and investigated through CFD simulation: ventilation roofs with outer-layer shape-stabilized PCM (VRSPO), middle-layer shape-stabilized PCM (VRSPM) and inner-layer shape-stabilized PCM (VRSPI). The effects of PCM and ventilation parameters on the thermal performance of three roofs were analyzed on a typical design day in summer in Wuhan. The results show that for VRSPO, VRSPM and VRSPI, the proper thicknesses of PCM are 35 mm, 25 mm and 15 mm; melting temperatures are 35~37 °C, 33~35 °C and 29~31 °C, respectively; the proper ventilation speeds are 2.5~2.6 m/s; and the optimum cavity radii are all 40 mm. The best performance can be obtained by placing PCM on the outer layer. The PCM of VRSPO has the highest number of days in which the phase change process occurs (specifically, 75 days in the summer). The application of VRSP can effectively reduce the internal surface temperature of the roof, by an average of 1.77 °C. The maximum and average inner surface temperatures of VRSPO in different weather conditions can be calculated using the daily average outdoor sol-air temperature or average dry bulb temperature by fitting equations. The structure can be used as a passive and active envelope in areas with hot and long summers.

Analysis of stress development during kiln drying of beech timber

Before use, timber must have reduced moisture content. Kiln drying causes cracking risk. This study aims to evaluate the risk of cracking during the drying of beech wood samples using the response surface methodology. Additionally, we aim to develop an empirical model that describes critical tensile stress during the early drying stages and the air parameters commonly used in kiln-drying schedules for beech timber, specifically, the effects of dry-bulb temperature (DBT) and wet-bulb depression (WBD). Nine options of drying conditions were analyzed in the study according to the Central Composite Design assumptions; they were combinations of three options of DBT (30, 40, and 50 °C) and three options of WBD (4, 5, and 6 °C). During the experiments, tangential shrinkage of the wood samples was completely restrained with a load cell that measured generated tensile drying stresses. The results of the ANOVA analysis confirmed that the DBT is the only factor significantly influencing the tensile stress at failure (σf). The second-order effect between DBT and WBD has also been confirmed. The drying condition causing the highest risk of cracking was shown using the multiple contour plots of tensile stresses and the moisture content at failure (MCf). Reliability theory was used to predict the cracking risk of wood tissue. The analysis confirmed the dependence of the cracking risk of wood tissue on drying conditions. When DBT is equal to 30 °C, the cracking risk increases as the air relative humidity (RH) decreases. However, during the drying of beech wood samples at a temperature of 50 °C, decreasing the RH in a range corresponding to the increase of WBD from 4 to 6 °C reduces the cracking risk, which is indicated by the lower moisture content at failure (MCf) of the wood samples.Graphical

Use of an earthen clay pot refrigerator with a thermoelectric cooler for extending farm produce shelf life

Conventional cold storage systems increase the risk of damage and are no longer used for the long-term storage of agricultural products. Thus, newer affordable and energy-efficient storage systems are required for enhancing the shelf life of farm produce. We investigated the coefficient of performance (COP) of an earthen clay pot refrigerator with a thermoelectric cooler (TEC) and explored cooling strategies to enhance cooling and electrical performance for increasing the shelf life of farm produce. We used MATLAB Simulink to analyze Peltier TEC module efficiency. The intrinsic characteristics, including the Seebeck coefficient (α), thermal conductivity (K), and electrical resistance (R), were determined, forming the basis of the Peltier module in MATLAB Simulink. Thermal characteristics such as COP and cooling capacity were studied as a function of system voltage (Vin) and current (Iin). The model was equipped with a 12 V/6 A, 60 W TEC and was verified by simulation investigation. We also used psychrometric measures (e.g., wet bulb, dry bulb, and dew point temperatures and relative humidity) to determine the extent of wetness or dryness of an object and monitor other temperatures of the clay pot refrigerator. The results revealed that the ambient temperature and cold and hot side temperatures fundamentally affected TEC performance. The TEC extended the shelf life of tomatoes, potatoes, and spinach by 60% compared to those stored under ambient conditions, thereby reducing their wastage. In conclusion, earthen refrigeration using TEC doubled the shelf life of farm produce compared to storage under ambient conditions, saving money, resources, labor, and supplies and enabling the development of efficient and environmentally friendly refrigeration systems.

Application of artificial intelligence in green building concept for energy auditing using drone technology under different environmental conditions

Thermal losses through weak building envelope is responsible for global current energy crises. Application of artificial intelligence and drone setups in green buildings can help in providing the sustainable solution the world is striving for years. The contemporary research incorporates a novel concept of measuring the wearing thermal resistances in the building envelope with the aid of a drone system. The above procedure conducts a throughout building analysis by considering three prime environmental parameters such as wind speed (WS), relative humidity (RH) and dry bulb temperature (DBT) with the aid of drone heat mapping procedure. The novelty of the study can be interpreted by the fact that prior researches have never explored the building envelope through a combination of drone and climatic conditions as variables in building areas difficult to access, thereby providing an easier, risk free, cost effective and efficient reading. Validation of the formula is authenticated by employing artificial intelligence-based software’s which are applied for data prediction and optimization. Artificial models are established to validate the variables for each output from the specified number of climatic inputs. The pareto-optimal conditions attained after analysis are 44.90% RH, 12.61 °C DBT and 5.20 km/h WS. The variables and thermal resistance were validated with response surface methodology method, thereby presenting lowest error rate and comprehensive R2 value, which are 0.547 and 0.97, respectively. Henceforth, employing drone-based technology in estimating building envelope discrepancies with the novel formula, yields consistent and effective assessment for development of green building, simultaneously reducing time and cost of the experimentation.

Agronomic responses of four garlic genotypes in two different locations

Agronomic performance of garlic is speculated strongly affected by genotype ´ environment interaction, however, interaction evaluation is rarely studied in Indonesia. This research aimed to study the agronomic response of four garlic varieties in two different locations. The research was conducted from April to December 2021 using Lumbu Putih, Lumbu Hijau, Lumbu Kuning, and Tawangmangu Baru genotypes grown in two locations, i.e., Lembang (1250 m asl) and Ciwidey (1200 m asl), Bandung, West Java using randomized complete block design with three replications. Results showed that genotypes ´ locations interaction was found for traits: plant height, pseudo-stem stem diameter, number of stomata, weight, and diameter of fresh and dried bulbs. Chlorophyll content (SPAD value) depends on genotype, height of fresh bulbs and percentage of weight loss depending on location, while number of leaves was independently affected by genotype and location. Lumbu Kuning produced the highest average fresh weight with considerable differences in both locations (Lembang: 52.01 g, Ciwidey: 31.87 g) and also had the highest weight of dry bulb when planted in Lembang (24.65 g). Pearson's correlation showed that the strongest positive correlation (r=0.91) was found between the weight of the fresh bulb and pseudo-stem diameter when garlic genotypes were planted in Ciwidey. The present study implies the importance to select suitable genotypes for a particular location.&#x0D; Keywords: genotype, environment, interaction, SPAD value, stomata, weight loss&#x0D;

Manufacturing and experimental analysis of a dew-point indirect evaporative cooler using fused deposition modelling 3D printing and polymeric materials

Evaporative cooling (EC) is an interesting alternative for reducing energy consumption and CO2 emission associated with the cooling of building. In the present work, a prototype of an innovative dew-point indirect evaporative cooler (DIEC) was manufactured by additive manufacturing technology. This prototype was made up of two types of materials: (a) one porous, with high water absorption capacity, polyvinyl alcohol (PVA) with felt, and therefore, high capacity of generate EC; and (b) another with high hydrophobic properties, polylactic acid (PLA) with bronze. The materials were characterised in terms of thermal, water absorption properties and morphological properties. Prior to manufacturing, a design of experiments was conducted in order to find the optimal manufacturing parameters. The prototype was produced through an innovative process, based on the simultaneous use of two extruders, and the manufacture of a porous layer of felt by dissolving the PVA matrix where the felt was initially embedded. Finally, the energy performance of the prototype was experimentally analysed, reaching values of dew-point effectiveness up to 0.9 and energy efficiency ratio up to 22.74 at 45 °C outside dry bulb temperature. These results show that additive manufacturing is promising for developing competitive compact and highly energy efficient DIEC systems.

Effect of roof modification on micro-climate of animal shed

A study was conducted to compare the effect of roof modification with use of polycarbonate plastic sheet and its variable height on micro-climate of growing dairy heifers. The experiment was carried out on three sheds for three seasons, viz. hot-dry (summer) season, hot-humid (rainy) season and winter season. In control group (C), loose housing system was followed and corrugated cemented sheets were used as roofing material. In T1, polycarbonate sheets were used as roofing material with fixed height. In T2, polycarbonate sheets were used as roofing material with adjustable height. Daily ambient temperature (°C), dry and wet bulb temperature outside the shed (macro-climate) and inside the shed (micro-climate), Relative Humidity and Temperature Humidity Index were being recorded twice a day at 9.00 am and 2: 30 pm for three continuous days at fortnightly interval. The average temperature of animal shed was significantly lower in T2 (27.30±0.10), followed by T1 (28.28±0.04) and C (29.46±0.16). In T2 lower temperature of shed than control was recorded during summer. Increasing the height of shed with ridge ventilation might have helped to dissipate heat easily in T2. The overall THI was significantly lower in T2 (76.50 ± 0.16) followed by T1 (77.91 ± 0.05) and higher in control (78.74 ± 0.25), which might be due to less penetration of solar radiation via reflective polycarbonate sheet and higher height of roof in T2. The micro-environment was more conducive and comfortable in T2 than control. Polycarbonate roofing with adjusted higher height may be a desirable choice for animal housing to mitigate heat stress in summer.

6 Comparison of Ammonia Concentrations Between Flush and Pull-Plug Waste Management Systems in Wean-Finish Swine Barns

Abstract Pig manure contains a wide variety of corrosion-inducing chemicals such as ammonia. Ammonia production and its release are influenced by temperature and moisture in the barn environment. Increased concentrations of ammonia can negatively affect pig health and growth, as well as pose a risk to human health. Additionally, even at decreased concentrations, ammonia reacts with humidity and causes premature corrosion of barn equipment and is a threat to the structural integrity of livestock buildings. In this study, ammonia concentrations were monitored and compared between two 880 head wean-finish swine facilities with different types of waste management systems. Both facilities had shallow manure pits, one containing a flush system and one containing a pull plug system to remove manure from the barns into the lagoon. Ammonia, dry-bulb air temperature, and relative humidity levels were measured every0 min for an entire wean-finish cycle (approximately 20 weeks). Data will be compared between the facilities to evaluate the impact of the waste management systems on indoor air quality conditions. Potential implications for pig health and growth and facility maintenance will be explored. Results will provide information on best management strategies for swine facilities.