Simulating Passive Ventilation Techniques By Using Different Software

Abstract

The ever increasing negative impacts of the global warming phenomenon on nature, environment, and people can no longer be ignored (Parry et al, 2007). While an im- portant factor causing this increase is the increasing amount of energy consumption and the associated greenhouse gas (GHG) emissions. One of the sources for this in- crease in energy consumption in the world is the building sector, where construction, operation, and maintenance activities account for approximately 40% of the energy demand, and 45% of the global carbon emission (Calautit et al, 2016). On the other hand, the energy demand for heating, ventilation, and air conditioning (HVAC) systems, which are a part of the building operation ac- tivities, is more than 40% of the total energy usage (Chenari et al, 2016). This situ- ation is aggravated further in regions with extreme climates, because of the need to provide thermal comfort to the occupants; i.e. heating in cold climates and air condi- tioning (AC) in hot climates. Since in such climates people spend most of their time in conditioned spaces, their indoor air quality (IAQ) and energy consumption are both important for human health and for the current energy problem. Consequent- ly, indoor air quality, thermal comfort, occupant behaviour, and the building’s ener- gy performance have a direct relationship with its energy consumption (Li, 2013). A study into traditional buildings reveals that passive solutions for providing thermal comfort are quite successful in reducing or even doing away with the need for ener- gy consumption. For example, in hot climates, traditional/natural ventilation tech- niques are useful in reducing cooling loads in buildings, while providing healthier IAQ, concurrently. However, if the most appropriate technique/ technology is not se- lected, its application can be quite costly. On the other hand, it is possible to simu- late the various options on a virtual model of the proposed building by using related software. Hence, this study begins with the investigation of traditional passive ven- tilation techniques, which have been used since ancient times; such as solar chim- neys, wind catchers, underground air passages, and atria. Simulating these passive SIMULATING PASSIVE VENTILATION TECHNIQUES BY USING DIFFERENT SOFTWARE 244 strategies is a complex exercise using computational fluid dynamics (CFD); there- fore, building 2 simulation strategies that can be used for evaluating the aforemen- tioned passive ventilation techniques virtually, will be studied. To this end, a general overview of the problems encountered in CFD based energy simulations will be in- vestigated; and case studies on the application of traditional passive ventilation tech- niques through various software will be examined. The aim of this research is to de- termine and select the most efficient methods and techniques for both passive ven- tilation and simulation of their applications, through a review of the related liter- ature. It is expected that this study will be helpful in conducting future research on the feasibility of adapting traditional architectural techniques that require less cool- ing/ heating energy for providing thermal comfort, even when they are located in ex- treme climates. In conclusion, this study examines the benefits of traditional passive ventilation techniques and their adaptation to current architecture by using energy simulation software for predicting the most appropriate solution.