RETRACTED: Simulation and Analysis of Various Ventilation Systems Given in an Example in the Same School of Indoor Air Quality

Abstract

The quality of internal air is one of the factors that affect the pace and quality of knowledge acquisition. Therefore, it is important that classrooms have high quality of air. Using computer simulation, the effect of various building ventilation variants on air quality in classrooms was analyzed. Two criteria were analyzed and six variants of ventilation. The analysis was carried out using the CONTAMW program, used for multi-zone analysis of ventilation and air quality in a building. As an indicator of air quality, the concentration of carbon dioxide in school halls was adopted. The analyses show that natural ventilation is not able to provide proper air exchange. Regular airing of classrooms during breaks can reduce the carbon dioxide concentration to 2500 ppm, however, there is a significant reduction in indoor temperature (even below 10 °C). The best control over the internal environment can be obtained by using a supply–exhaust ventilation system with heat recovery. Obtaining a higher stabilization of ventilation is achieved by supplying additional energy to drive fans, however, this is only a small amount of energy compared to the cost of heat for heating the building (maximum 2%).

Precise Explicit Approximations of the Colebrook-White Equation for Engineering Systems

“…• with a deviation up to 5.36% (Fig. 2) within Re = 2320…10 9 , D e =D ¼ 0. . .0:65 for rough engineering calculations:…”

“…• with a deviation up to 0.00072% (Fig. 3) at Re = 2320…10 9 , D e =D ¼ 0. . .0:65 for the most application in engineering and science (further refinement is impractical):…”

“…Therefore, instead of performing iterations (11), another approach is proposed to achieve high accuracy. We assume a sufficiently dense grid of Reynolds numbers Re = 2320…10 9 with a variable step DRe: DRe = 20 at Re 10000, DRe = 200 at 10000 < Re 100000, DRe = 2000 at 100000 < Re 1000000, and so on. Similarly, we take a grid of relative equivalent roughness D e /D = 0…0.…”

“…Due to increasing energy efficiency, modern systems are highly automated. A significant amount of research is devoted to the appropriate air distributors [3][4][5][6] or optimal control strategies [7][8][9]. However, the simulation of hydraulic and aerodynamic conditions [10] is no less important.…”

Investigation of the use of various materials for the construction of an enthalpy exchanger

“…Indoor air quality based on CO2 concentration depending on ventilation is investigated in [24]. Lowering of indoor air quality and subsequent recommendation of forced ventilation with heat recovery is discussed in [25].…”