Heat Flux and Thermal Characteristics of Electrically Heated Windows: A Case Study

Energy loss through windows can be high relatively compared to other opaque surfaces because insulation performance of fenestration parts is lower in the building envelope. Electrically heated window systems are used to improve the indoor environment, prevent condensation, and increase building energy efficiency. The purpose of this study is to analyze the thermal behaviors of a heated window under a field experiment condition. Experiments were conducted during the winter season (i.e., January and February) with the energy-efficient house that residents occupy. To collect measured data from the experimental house, temperature and heat flux meter sensors were used for the analysis of heat flow patterns. Such measured data were used to calculate heat gain ratios and compare temperature and dew point distribution profiles of heated windows with input power values under the changed condition in the operating temperature of the heated glazing. Results from this study indicated that the input average heat gain ratio was analyzed to be 75.2% in the south-facing and 83.8% in the north-facing at nighttime. Additionally, compared to January, reducing the operating temperature of the heated glazing by 3 °C decreased the input energy in February by 44% and 41% for the south-facing and north-facing windows, respectively. Through such field measurement study, various interesting results that could not be found in controlled laboratory chamber conditions were captured, indicating that the necessity of establishing various control strategies should be considered for the development and commercialization of heated windows.

Thermohaline structure in the equatorial Indian Ocean during Monsoon-77

The hydrographic and BT data sets collected in the upper 200 m water column along three zonal transects (2°N, equator and 2°S) in the equatorial Indian Ocean (between 70oE and 90OE) made by USSR ships during the field observational programme of Monsoon-77 (end May/early June 1977) showed prominent eastward depression of thermocline in association with the surface easterly equatorial jet. In the central indian. Ocean, the mixed layer cooling and deepening rates were weak with the. Onset and sway of the summer monsoon over a two month period from end May 1977, but relatively significant changes were noticed in the salinity of the upper 200 m water column. In this region, on a synoptic scale a mild increase in SST is in accor4ance with the net surface heat gain during the last week of July 1977.

Solar Radiation Limits the Use of Paddocks by Laying Hens Raised in the Free-range System

Laying hens on the Free-range systems are susceptible to challenging situations in relation to the rearing environment. Therefore, this work evaluated how solar radiation influences the behaviour of laying hens raised in a Free-range system, in the Brazilian Savanna. The activities included data collection of meteorological variables and behavioural analysis of three-hundred commercial laying hens in relation to the frequency of use of indoor and outdoor areas of rearing housing. The solar radiation is the main factor that directly affects the heat gain of production animals, in this experiment had a high amplitude during all day, going from 33.42 W m-2, to 756.98 W m-2. It was observed that the highest frequency of 79% and 91% use of the barn areas by the hens was at 8am and 4pm, respectively. The internal area of the housing was more used by hens 87% and 68% at 12h and 14h, respectively. Hens were not observed in the paddocks at noon and 2 pm. Hens spend more than 6 hours of the day inside the housing to provide shelter from solar radiation. Which the conclusion the solar radiation influences the behaviour of laying hens, at times of the day of the higher incidence of radiation, and high air and global temperatures, it was not observed the presence of hens in the external areas of the housing, especially with the use of the paddocks, at these times the hens seek shelter inside the housing to get away from the incidence of direct solar radiation.

Evaluating the 35°C wet-bulb temperature adaptability threshold for young, healthy adults (PSU HEAT)

A wet-bulb temperature of 35°C has been theorized to be the limit to human adaptability to extreme heat, a growing concern in the face of continued and predicted accelerated climate change. While this theorized threshold is based in physiological principles it has not been tested using empirical data. This study examined the critical wet-bulb temperature (Twb, crit) at which heat stress becomes uncompensable in young, healthy adults performing tasks at modest metabolic rates mimicking basic activities of daily life. Across six experimentally determined environmental limits, no subject's Twb, crit reached the 35°C limit and all means were significantly lower than the theoretical 35°C threshold. Mean Twb, crit values were relatively constant across 36-40°C humid environments and averaged 30.55±0.98 °C but progressively decreased (higher deviation from 35°C) in hotter, dry ambient environments. Twb, crit was significantly associated with mean skin temperature (and a faster warming rate of the skin) due to larger increases in dry heat gain in the hot-dry environments. As sweat rates did not significantly differ among experimental environments, evaporative cooling was outpaced by dry heat gain in hot-dry conditions, causing larger deviations from the theoretical 35°C adaptability threshold. In summary, a wet-bulb temperature threshold cannot be applied to human adaptability across all climatic conditions and where appropriate (high humidity), that threshold is well below 35°C.

Energy Savings and Carbon Emission Mitigation Prospective of Building’s Glazing Variety, Window-to-Wall Ratio and Wall Thickness

Strategic selection of glazing, its window-to-wall ratio, and wall thickness of building reduce the energy consumption in the built environment. This paper presents the experimental results of solar optical properties of five glasses: clear, tinted bronze, tinted green, bronze reflective, and polymer dispersed liquid crystal glasses. Laterite room models were modeled with four different thicknesses and four different glasses using Design Builder, and thermal simulation tests were carried out using Energy Plus. The energy savings and carbon emission mitigation prospective of a building’s glazing variety, window-to-wall ratio (WWR), and wall thickness were investigated. The results revealed that among the five window glasses studied, the polymer dispersed liquid crystal glazing window (PDLCGW) was found to be the most energy-efficient for low heat gain in laterite rooms. The laterite room with 0.23 m wall thickness and 40% PDLCGW WWR reduced 18.9% heat gain in comparison with the laterite room with 0.23 m wall thickness and 40% clear glass WWR. The laterite room of 0.23 m wall thickness with PDLCGW glazing of 40% WWR enhanced cooling cost savings up to USD 31.9 compared to the laterite room of 0.08 m wall thickness with 40% PDLCGW. The laterite room of 0.23 m wall thickness with PDLCGW glazing of 40% WWR also showed improved carbon mitigation of 516 kg of CO2/year compared to the 0.23 m wall thickness laterite room of 40% WWR with clear glass glazing. The results also showed that the laterite room with 0.23 m wall thickness and 100% clear glass WWR increased heat gain by 28.2% in comparison with the laterite room with 0.23 m wall thickness and 20% clear glass WWR. The results of this article are essential for the strategic design of buildings for energy saving and emission reduction.

Exergy Analysis of Air Conditioning (AC) System in Suite Room Santika Hotel Yogyakarta

Air Conditioning are major contributors to energy consumption in-suite room Santika Hotel Yogyakarta. A suite room is a choice of rooms with the best facilities compared to other rooms, so comfort is one of the services that must be optimized. The ain is to determine the conduction heat load of various components in the room. Heat conduction load calculation includes heat load through the glass on the east 1253.18 BTU/hr, conduction heat load through the wall to the south 606.14 BTU/hr, solar radiation through glass 1268.48 BTU/hr, heat gain from people 1980 BTU/hr, electrical equipment/lights 2193 BTU/hr and heat gain from ventilation 13053.6 BTU/hr. The total amount of heat gain used in exergy analysis calculation with a value of 3053.16 BTU/hr.

Selection of a method for calculating heat gain from solar radiation to determine the load on the climate system of the cabin of a mobile car

Introduction. The article analyzes and selects the most rational methods for calculating the heat gain from solar radiation. The correct calculation of this component of the heat balance allows you to correctly determine the power of the projected cabin climate system, which will ensure optimal working conditions at the workplace of mobile car operators. Problem Statement. The objective of this study is to analyze and select a rational method for calculating heat gain from solar radiation for the correct determination of the thermal load on the climate system of the cabin of a mobile car. Theoretical Part. To implement the task, the most common methods for calculating solar radiation were described and analyzed in detail and the most accurate ones were recommended. Conclusions. The more labor-intensive method of V.N. Bogoslovskiy (taking into account the time of day) can be recommended for automated calculations in Excel, and the method of P.Y. Gamburg (taking into account the sides of the horizon) — for comparative estimated engineering calculations. When conducting "in-depth" model calculations and accounting for solar radiation, the ASHRAE method is explicitly suitable, which has two important advantages: it takes into account the solar factor in relation to a specific type of glazing and is adapted for automated calculations in ANSYS FLUENT.

Calibration of DSF model for real-time control

Double Skin Façades are complex fenestration systems capable to control solar heat gain and ventilation in buildings. Due to the high flexibility of such innovative components, having energy models able to replicate the thermal behaviour of the Double Skin Facades is of utmost importance for their optimal control and integration with building automation strategies. In this context, a numerical model has been developed and validate within the experimental data. The methodological steps are presented in this work and in the last section, the potential applications of the model are discussed.