Energetic, Economic and Environmental (3E) Assessment and Design of Solar-Powered HVAC Systems in Pakistan

Abstract

Rapid urbanization, global warming and enhanced quality of life have significantly increased the demand of indoor thermal comfort and air conditioning systems are not a luxury anymore, but a necessity. In order to fulfil this need, it is imperative to develop affordable and environmentally friendly cooling solutions for buildings. In this work, the 3E performance (energetic, economic and environmental) of electrically driven water-cooled vapour compression systems and thermally (solar) driven vapour absorption cooling systems are evaluated and the parameters affecting the performance of solar-driven vapour absorption systems are investigated. The energy simulation software TRNSYS is used to simulate the performance of both systems in order to fulfil the cooling needs of an industrial manufacturing building for the typical climate conditions for Lahore, Pakistan. Primary energy saving, initial investment, operational cost, and carbon footprint indices are used to analyse the performance of both systems. In addition, a parametric code is written in Python and linked with TRNSYS to perform a parametric study to investigate the effects of various parameters such as solar field size, storage tank volume, optimum annual and monthly collector angles, and flow rate in the solar field on the solar-driven vapour absorption chiller performance. The results reveal that around 5% more energy can be absorbed per collector surface area by changing the solar tilt angle on a monthly basis compared to one fixed angle. The analysis shows that electrically driven vapour compression-based cooling systems have much higher running cost and are potentially hazardous for the environment but have lower capital costs. On the other hand, solar thermal systems have lower running costs and emissions but require further reductions in the capital costs or government subsidies to make them viable.

Technologies for Air Condiotioning Powered by Alternative Energy Sources a Brief Review

“…In view of the search for alternative energy sources and considering that there are polluting fuels in the atmosphere such as coal, heavy oil and tar; natural gas presents itself favorably [7]. When comparing natural gas with other biofuels, there is less CO2 emission.…”

“…Although the Brazilian matrix comes considerably from renewable sources, the socio-environmental impacts of some of these sources are considerable, when compared to other energy sources [5] The correlation between the evolution of energy demand and economic growth measured by GDP has been recurrent, and the increase in energy consumption can be attributed to air conditioning systems [6]. The demand for the expansion of the use of air conditioning and refrigeration systems can be perceived due to population growth, global warming, the increase in the social standard of living (increase in equipment inside buildings, lighting, increased demand for occupant comfort) and architectural characteristics, such as: the huge facades and the use of heat-absorbing surfaces [7,8]. In addition, it is known that around 30% of the energy demand of an enterprise is destined to air conditioning systems in different sectors (homes, schools, canteens, public offices, hospitals, markets, etc.)…”

Technologies for Air Conditioning Powered by Alternative Energy Sources: A Brief Review

“…Absorption chillers are a promising alternative, exhibiting considerable energysaving benefits, potential economic viability, and environmentally friendly features [16]. Given the search for alternative energy sources and considering that there are polluting fuels in the atmosphere, such as coal, heavy oil, and tar, natural gas presents itself favorably [7]. When comparing natural gas with other biofuels, there is less CO2 emission.…”

“…The correlation between the evolution of energy demand and economic growth measured by GDP has been recurrent, and the increase in energy consumption can be attributed to air conditioning systems [6]. The demand for the expansion in using air conditioning and refrigeration systems occurred due to population growth, global warming, the increase in the social standard of living, and architectural characteristics, among others [7,8]. In addition, air conditioning systems consume around 30% of an enterprise's energy demand in different sectors (homes, schools, canteens, public offices, hospitals, and markets) [9].…”

Realistic Simulation Tool for practical Analysis of Solar Cooling Thermal Systems driven by Linear Fresnel Collectors

“…In this period, several configurations have been studied and analyzed in terms of stages, absorberrefrigerant pairs, drive medium, applications and cooling capacities. In the literature, studies of solar cooling thermal systems have been found with single-effect absorption machines and driven by various types of solar collectors: with nonconcentrating or stationary solar collectors [4,5,6,7,8,9,10,11,12,13,14,15,16], with parabolic cylinder collectors [6,14,17,18] and with linear Fresnel collectors [19]. Also, systems with absorption machines with two or more stages and with various types of solar collectors: with parabolic cylinder collectors [4,20] and with linear Fresnel collectors [21].…”