Simulation study for natural ventilation retrofitting techniques in educational classrooms – A case study

Abstract

Building retrofitting plays a critical role in achieving sustainable development and is an efficient way to improve the indoor air quality (IAQ) of existing spaces. The IAQ in classrooms has a significant impact on the health and academic achievement of students. However, improving the IAQ of existing classrooms is challenging if minimum architectural modifications are allowed. Different natural ventilation retrofitting techniques were proposed to improve the IAQ in existing classrooms at Jordan University of Science and Technology, which is located in a hot arid region. Computer simulations were used to analyze the ventilation rate, indoor operative temperature, relative humidity, and CO 2 concentration in the base Case classroom and after the implementation of the proposed retrofitting techniques. Simulation results were compared with those obtained in the base case to determine the most efficient natural ventilation retrofitting technique. The best results were obtained by using a solar chimney to assist a wind tower, which resulted in an increase in the comfort hours during the occupation time, an improvement in the average monthly ventilation rate range, a decrease in the CO2 concentration, and an improvement in the relative humidity ratio. An energy-saving of 39% would be achieved compared with the use of split unit air condition systems. Economic assessment of the proposed system using net present value indicates positive economic viability.

Interaction between Thermal Comfort, Indoor Air Quality and Ventilation Energy Consumption of Educational Buildings: A Comprehensive Review

“…Ma'bdeh et al [150] compared different natural ventilation retrofitting techniques in terms of the ventilation rate, indoor operative temperature, relative humidity, and CO 2 concentration. Among these techniques, the solar chimney assisted with a wind tower can achieve the highest energy-saving of 39% compared with baseline air conditioning systems.…”

Window-Windcatcher for Enhanced Thermal Comfort, Natural Ventilation and Reduced COVID-19 Transmission

“…As discussed in Section 2, the ventilation rate has been evaluated against the required ventilation rate (Q required ) as per ASHRAE standards [30]. The acceptable ventilation rate in the studied residential building was estimated using Equation (6) [30] (i.e., approximately 168.5 L/s). The actual ventilation rate (Q actual ) has been estimated computationally using ANSYS, and the ventilation performance has been benchmarked by the actualto-required ventilation ratio (n Q ) using Equation (7) [30].…”

“…On average, people spend up to 90% of their time working and living indoors. The risk of sick building syndrome (SBS), metabolic diseases and transmission of COVID-19 and other airborne viral diseases are increased in air-conditioned buildings compared to naturally ventilated buildings [6]. It is, thus, critical to ensure good IAQ to maintain health and productivity [5].…”

“…Passive cooling techniques have been studied extensively [7]. Acceptable thermal comfort and IAQ using passive cooling can be achieved with only a small fraction of the energy consumed by mechanical ventilation systems [6]. Natural ventilation is one of the leading passive cooling strategies that effectively improve the indoor atmosphere by: (1) providing good IAQ and (2) improving thermal comfort, through affecting ventilation rates, air velocity, temperature and humidity [7].…”

“…Airflow and ventilation systems play a significant role in the airborne transmission of pathogens; improving ventilation decreases the risk of transmission. Identifying how the novel window-windcatcher improves ventilation is the focus of our work here [6,7]. The design of a ventilation system depends on the ability to contain, mitigate, and remove airborne pollutants through air change and inward indoor airflow [17].…”