Mechanical ventilation systems enhance air quality by providing fresh air to structures. Ventilation systems use a network of fans and ducts that remove moisture, odours and other contaminants. Ventilation systems utilise air pressure to move fresh air through residential, industrial and commercial buildings, by natural or mechanical means. Natural ventilation occurs by circulating air through vents, windows, doors and open spaces.
Mechanical ventilation systems not only provide improved air quality, by removing allergens and other pollutants, but they also offer a method of control over the volume of air coming into the structure. Ventilation systems eliminate undesirable air that infiltrates from a crawl space or garage. Ventilation systems help improve the comfort level by continuously creating an airflow, which filters, dehumidifies and conditions exterior air.
Exhaust mechanical ventilation systems are usually in areas that experience cold weather. This system constantly removes musty indoor air. Many kitchens and bathrooms have exhaust ventilation systems. Exhaust mechanical systems cause a depressurisation to occur in buildings; avoid using exhaust ventilation systems in hot, humid areas because the fan pulls hot air from the outside through cracks and openings in the walls of the building. When the hot air blends with the cooler interior air, it may result in moisture problems.
Designed for hot and mixed-climate regions, supply ventilation systems rely on a fan and ducts to draw air through intake vents. The unit distributes air to various locations within a structure by using one of two techniques. The first method entails a single fan and two sets of ductwork used only for ventilation. The other technique involves attaching an exterior air intake vent to the main return duct on a heating, ventilation and air conditioning unit, which delivers fresh air. By connecting the vent to the primary return air duct, it conditions the outside air before distributing the air inside the building.
Balanced ventilation systems work in a various climates. The unit moves air in and out of the structure in equal amounts. The system relies on two fans --- one designated for each job. Two types of balance ventilation systems exist: heat recovery ventilation (HRV) and energy recovery ventilation (ERV). An HRV system transports heat from exhaust air to incoming air during the colder months. During the summer months, the unit transfers incoming air to exhaust air. An ERV system moves moisture and heat between incoming and exhaust air.