With the popularity of the central fresh air system, the central fresh air system has been used as a household ventilation equipment into the household. Central fresh air system can provide fresh air required for human health, in the case of 24 hours without window ventilation. In the family residence in China, the use of central air system has been more and more widely, we usually use the central air system according to the air flow organization can be divided into: a one-way flow of central air system, two-way flow of central fresh air system, central fresh air heat recovery system.

1, one-way flow of fresh air system features and the scope of application of
that "forced exhaust, natural air supply". For example: in the residential air outlet installed in the bathroom living room air gathering place, the air outlet is directly connected with the toilet air inlet into the air shaft, installed at the lower part of the bedroom, living room window, and directly connected outdoor. When the system is running, the indoor air through the air outlet continuously to the outside row, and the indoor negative pressure, fresh air through the air inlet filter, dehumidification, deodorization, noise reduction, Everfount added in twenty-four hours.
scope of application: the amount of air exhaust between 0.6-1.2 times the number of hours / hours of apartments, villas, residential. Features: simple structure, there is no complex pipe in the room, investment in the province is currently widely used in residential and hotel systems.

2, two-way flow of fresh air system features and scope of
by a group of forced air supply and forced air exhaust system, and one-way flow is the difference between the fresh air with the air supply system into the indoor pipeline. The flow direction of fresh air can be designed and arranged according to specific requirements. Fresh air into the room can be selected according to the requirements of filtration, sterilization and preheating.
scope of application: the ventilation volume is greater than 1.2 times the number of times / hours of business offices, KTV rooms, laboratories, hospitals and other buildings. Features: fresh air flow organization can be designed freely, but also can be placed in accordance with the requirements of a variety of air handling equipment for a variety of special requirements for the quality of fresh air. The quality of the air in the room with no windows or surrounding buildings does not meet the requirements. The indoor air is effectively isolated from the micro positive pressure, through the cracks of doors and windows into the dirty air

central air system is collecting several functions of ventilation, high efficiency and energy saving, low noise in the air equipment. The utility model can fundamentally solve the problems of indoor ventilation, air conditioning disease prevention, mildew prevention of furniture and clothes, removing harmful gas, etc.. In order to meet the different needs of the room, the central air conditioning system designed a one-way flow of fresh air system, two-way flow of fresh air system and heat recovery fresh air system, a comprehensive guarantee indoor ventilation.