Client runs a 150 square meters restaurant in Dubai, divides into dinning area, bar area and hookah area. At the pandemic era, people care about building air quality more than ever, at both indoor and outdoor circumstances. At Dubai, hot season is long and burning, even inside of building or house. The air is dry, making people feel uncomfortable. Client tried with a couple of cassette type air conditioners, the temperature in some areas can somehow be maintained at 23°C to 27°C, But due to the lake of fresh air and insufficient ventilation and air purification, temperature inside of the room may fluctuate, and smell of smoke may cross contaminate.