1. The air volume of air conditioning air return system of the air duct machine is insufficient, which will make the problem appear particularly prominent. Most of the reasons are the insufficient area of the return air tube and the return air inlet (the design is unreasonable).
Suggestions for rectification: increase the air return pipe and air outlet size, or increase air return pipe and air return.
2, air supply and exhaust air flow circuit, air outlet has not been sent to send delivery room air conditioning area will flow to the nearest air return area.
3. For the sake of convenience and saving, the wind pipe adopts a long metal hose. When the wind speed is larger than that of the 3m/s metal hose, the wind pipe resistance increased rapidly, while the household central air-conditioning indoor machine fan pressure is small. If the wind pressure can not overcome the excessive resistance, the actual air volume will be greatly lower than the rated air volume.