Reducing the cooling load of an residence building by humidifying ventilation air (experimental and numerical study)

Abstract

The study investigates the benefit of utilizing the waste water which washed the walkway of residential buildings to humidity the ventilation air that supplied to the building. The water will collect in a concrete channel section (100 * 100 mm) in contact with the wall of the building towards the drainage network. The side adjacent to the wall contains (5mm) diameter holes ending with an air gap located behind the external wall metallic finishing. The ventilation (environmental) air (naturally or forcibly) passes through the holes to the air gap through the holes. This causes the temperature to decrease and the moisture content of the air is increased. The moving air passes through the gap towards the environment through the openings at the top of the wall. The study is carried out Baghdad city (latitude 33.2 ° North) using two types of external finishing material (Aluminum sheets) reflector and plates coated with thermal dyes. Also, employed an air gap or an air gap with thermal insulation thickness (50 mm) placed behind the plate. As well as the case of the air gap is open to the environment during day and night or closed day and “open at night” with an exhaust fan that worked by solar energy. The results showed that in the case of the air gap behind the external finishing material with thermal insulation, the fan operates during the day hours of the day and the area (1 m2 ), the cooling load required during the summer is (306 kW-hr / m2-cooling season). While the cooling load of the common wall is (609 kW-hr / m2-cooling season. Thus, the savings rate is (49.8%) when used this technique.