Daylighting, artificial electric lighting, solar heat gain, and space-heating energy performance analyses of electrochromic argon gas-filled smart windows retrofitted to the building

The inevitability to reduce CO2 emissions to avoid preventable climate change is widely being yelped. To minimise the impact of rapidly changing climate, this paper presents novel research findings and contributes to developing electrochromic argon gas-filled glazed smart windows retrofitted to the building with IoT based transparency control. In this, the comparative analyses of the daylighting, electrical lighting, solar heat gain, and space-heating load of the building using the dynamic thermal and electric lighting modelling methods based on real weather temperatures are presented. The daylighting analysis results implicate that the building with electrochromic argon gas-filled smart windows reduced 19% of daylight illuminance during summer months compared with the building retrofitted with double air-filled glazed windows daylight factor remains consistent. As such, the solar heat gains analysis results implicate at least 50 % annual solar heat gain reduction predicted in the building with electrochromic argon gas-filled smart windows in comparison to double air-filled windows. This leads to the conclusion of the space-heating energy analysis that implicates the highest contribution to the space heating demand is the solar heat gain caused by double air-filled glazed windows. The results confirm that the LED artificial electric lighting system requires fewer fittings and thus total power load compared to the fluorescent lighting system, throughout the year, to the building with electrochromic argon gas-filled glazed smart windows. The daylight controls are linked to the electrochromic argon gas-filled glazed smart windows, so they only operate when the glazing is tinted, or the daylight level drops below a set level; this will reduce the energy usage and also lower the space heating of the room.

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Reducing Roof Solar Heat Gain by Using Double-Skin Ventilated Roofs

Engineering and Technology Journal ◽

10.30684/etj.v38i3a.462 ◽

2020 ◽

Vol 38 (3A) ◽

pp. 402-411

Author(s):

Mohannad R. Ghanim ◽

Sabah T. Ahmed

Keyword(s):

Inclination Angle ◽

Convection Heat Transfer ◽

Ventilation Rate ◽

Channel Length ◽

Air Gap ◽

Galvanized Steel ◽

Heat Gain ◽

Solar Heat ◽

Double Skin ◽

Solar Heat Gain

Double skin ventilated roof is one of the important passive cooling techniques to reduce solar heat gain through roofs. In this research, an experimental study was performed to investigate the thermal behaviour of a double skin roof model. The model was made of two parallel galvanized steel plates. Galvanized steel has been used in the roof construction of industrial buildings and storehouses in Iraq. The effect of inclination angle (ϴ) from the horizontal and the spacing (S) between the plates was investigated at different radiation intensities. It is found that using a double skin roof arrangement with a sufficient air gap (S) can reduce the heat gain significantly. The higher the inclination angle (ϴ) the higher the ventilation rate, the lower the heat gain through the roof. In this study, increasing the air gap from 2 cm to 4 cm reduced the heat gain significantly but when the gap was further increased to 6 cm, the reduction in the heat flux was insignificant. A dimensionless correlation was also reduced between Nusselt number () and the single parameter where L is the channel length. This correlation can be handily utilized for designing of engineering applications dealing with high temperature difference natural convection heat transfer.

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Effects of External Louvers on Solar Heat Gain and Energy Consumption of an Office Building in Different Climates of Iran

Iranian Journal of Science and Technology Transactions of Mechanical Engineering ◽

10.1007/s40997-021-00449-x ◽

2021 ◽

Author(s):

Jalil Shaeri ◽

Mahmood Yaghoubi ◽

Amin Habibi

Keyword(s):

Energy Consumption ◽

Office Building ◽

Heat Gain ◽

Solar Heat ◽

Solar Heat Gain ◽

Different Climates

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VEGETATION INSULATION SCREEN AS A PASSIVE COOLING SYSTEM IN HOT HUMID CLIMATE: HEAT AND MASS EXCHANGES

International Journal of Advanced Research ◽

10.21474/ijar01/13693 ◽

2021 ◽

Vol 9 (10) ◽

pp. 1368-1378

Author(s):

Hodo-Abalo Samah ◽

◽

Magolmeena Banna ◽

Belkacem Zeghmati ◽

◽

...

Keyword(s):

Leaf Area Index ◽

Leaf Area ◽

Cooling System ◽

Gain Factor ◽

Passive Cooling ◽

Humid Climate ◽

Heat Gain ◽

Area Index ◽

Solar Heat ◽

Solar Heat Gain

Planted roofs are passive cooling techniques that reduce the thermal load of buildings. In this paper, a Dynamic mathematical model based ontime average Navier-Stokes equationsfor a plantedroof in hothumidclimates has beendeveloped for evaluating the cooling potential.Transfer equations are solved using a finite difference scheme and Thomas algorithm. The model was applied for the simulation of a planted roof in Togolese climate conditions. Results showed that, evapotranspiration and Solar Heat gain Factor are functions of the Leaf Area Index LAI which is the most important parameter when considering the foliage material. For LAI equal to 6, latent heat peak value reaches 900 W.m-2while that of sensible heat is around 350 W.m-2. Solar heat gain factor can bereducedto 15% fortheplantedroofagainst 45% forbareroof. It is clearly proved that the foliage density and hence the vegetation canopy type selection greatly influence the thermal efficiency of the bioclimatic insulation screen. A larger Leaf Area Index reduces the solar flux penetration and increases evapotranspiration which is an important parameter when considering surrounding microclimate formation.

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Effects of solar radiation and wind speed on metabolic heat production by two mammals with contrasting coat colours.

Journal of Experimental Biology ◽

10.1242/jeb.198.7.1499 ◽

1995 ◽

Vol 198 (7) ◽

pp. 1499-1507 ◽

Cited By ~ 3

Author(s):

G E Walsberg ◽

B O Wolf

Keyword(s):

Wind Speed ◽

Solar Radiation ◽

Heat Production ◽

Metabolic Heat Production ◽

Heat Gain ◽

Solar Heat ◽

Wind Speeds ◽

Convective Heat Loss ◽

Metabolic Heat ◽

Solar Heat Gain

We report the first empirical data describing the interactive effects of simultaneous changes in irradiance and convection on energy expenditure by live mammals. Whole-animal rates of solar heat gain and convective heat loss were measured for representatives of two ground squirrel species, Spermophilus lateralis and Spermophilus saturatus, that contrast in coloration. Radiative heat gain was quantified as the decrease in metabolic heat production caused by the animal's exposure to simulated solar radiation. Changes in convective heat loss were quantified as the variation in metabolic heat production caused by changes in wind speed. For both species, exposure to 780 W m-2 of simulated solar radiation significantly reduced metabolic heat production at all wind speeds measured. Reductions were greatest at lower wind speeds, reaching 42% in S. lateralis and 29% in S. saturatus. Solar heat gain, expressed per unit body surface area, did not differ significantly between the two species. This heat gain equalled 14-21% of the radiant energy intercepted by S. lateralis and 18-22% of that intercepted by S. saturatus. Body resistance, an index of animal insulation, declined by only 10% in S. saturatus and 13% in S. lateralis as wind speed increased from 0.5 to 4.0 ms-1. These data demonstrate that solar heat gain can be essentially constant, despite marked differences in animal coloration, and that variable exposure to wind and sunlight can have important consequences for both thermoregulatory stress experienced by animals and their patterns of energy allocation.

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A COMPUTER AIDED OPTIMUM DESIGN METHOD OF BUILDINGS FOR MAXIMUM SOLAR HEAT GAIN

Sun: Mankind's Future Source of Energy ◽

10.1016/b978-1-4832-8407-1.50316-0 ◽

1978 ◽

pp. 1643-1652

Author(s):

BIROL KILKIS ◽

Bilgin Kaftanoglu

Keyword(s):

Optimum Design ◽

Design Method ◽

Heat Gain ◽

Solar Heat ◽

Computer Aided ◽

Solar Heat Gain

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Analysis of Selecting Cooling Load Coefficient Methods

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.501-504.2311 ◽

2014 ◽

Vol 501-504 ◽

pp. 2311-2314

Author(s):

Jian Chen ◽

Wen Wen Xie

Keyword(s):

Heat Source ◽

Cooling Load ◽

Heat Gain ◽

Solar Heat ◽

Correct Calculation ◽

Solar Heat Gain

This paper analyses the method of how to select the coefficient of cooling load caused by indoor heat source (including equipment, lighting and personnel) and solar heat gain, which provides a basis for the correct calculation of air condition cooling load.

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