ASSESSMENT OF AIR CHANGE EFFECTIVENESS AND THERMAL COMFORT IN A NATURALLY VENTILATED KITCHEN WITH INSECT-PROOF SCREEN USING CFD

Many dwellings in warm-humid climates attain a comfortable environment by natural ventilation.The opening of exterior windows for ventilation allows the entry of insects along with the breeze.As a remedy,occupants install insect-proof screens on windows resulting in reduced airflow into the interior.This study attempts to evaluate the air change effectiveness and thermal comfort in a residential kitchen with insect-proof screens.A kitchen with insect-proof screens on the windows is compared with a case without insect-proof screens.Numerical simulation was conducted using ANSYS Fluent 2019 R2.The insect-proof screen is modelled as a porous media.The air velocity and temperature measurements were validated by measurements in a real scenario.The presence of insect-proof screens reduced the air velocity inside the space by 82%.However,the airflow pattern in the case with screens was more uniformly distributed.The mean age of the air was considerably higher in the case with insect-proof screens,which in turn resulted in a reduced ACE.The presence of an insect-proof screen resulted in a Predicted Mean Vote(PMV)of 2.79 indicating a‘hot’sensation,whereas in the other case,the comfort vote is only 1.93 indicating a‘warm’sensation.The presence of insect-proof screens on windows reduced the air velocity and ventilation efficiency,contributing to increased thermal discomfort in the kitchen.