1. In newly renovated houses, chemical gases harm our bodies, and we have to open and close the windows every day. 
2. Even after living there for several years, toxic and harmful gases still plague our lives. 
3. The dust in the room, mosquito bites, noise, etc. affect our rest and study. 
4. People will worry about rain, dust, thieves, and children after opening the windows.
5. Water vapor accumulates, and clothes and valuables are prone to mold and moisture.
6. Cigarettes in the room, oil fumes in the kitchen, and odors in the bathroom
7. The room type makes it dark and unventilated, and there are no north and south windows.
8. Fatigue, headache, blushing, and drowsiness in an air-conditioned room, commonly known as "air conditioning disease"
9. The impact of SARS and other airborne diseases on people’s health awarenes. 
10. The promulgation and enforcement of relevant regulations such as indoor pollution control specifications, fresh air volume requirements for small central air conditioners, etc.

In newly renovated houses, chemical gases harm our bodies, and we have to open and close the windows every day

The following are the precautions for installing a ceiling-mounted fresh air ventilator:

a. The hoisting foundation of the fresh air blower must be level and solid.

b. The pipe diameter at the outlet of the fresh air blower can only be made larger, not smaller. Finally, insect-proof nets must be installed at the air outlet and air inlet, and a weather cap must be added when the air is directed upward.

c. The steel bracket of the fresh air blower must be fixed on the concrete foundation, and a rubber vibration-absorbing pad must be added between the steel bracket of the fresh air blower and the foundation. All fans and motor components are installed on a single piece of steel bracket, and the steel frame is installed on the vibration-absorbing pad on the top of the foundation. The vibration-absorbing pad is preferably a porous rubber plate.

d. The fresh air fan and the air duct should be connected with a hose (flexible material and non-combustible). The length should not be less than 200mm, and the pipe diameter should be the same as the fan inlet and outlet size. In order to ensure that the hose does not twist and deform during system operation, it should be installed with appropriate tightness. The canvas hose installed at the suction end of the fan can be installed slightly tighter to prevent it from being sucked in when the fan is running and reduce the cross-sectional size of the canvas hose.