Floor supply and ceiling supply are both for the bidirectional flow fresh air system of piped distribution. This kind of fresh air system needs to deliver and return air through the system. In the ceiling supply mode, the fresh air and polluted air of the fresh air system are both delivered through the air openings located on the ceiling. In the floor supply mode, the supply air is achieved by the air openings located on the floor or low-end wall, and the return air is completed by the air openings on the ceiling. With adequate air volume to meet the demand, both the ceiling supply mode and the floor supply mode perform well. However, the latter is slightly better, so it should be given priority under favorable conditions.
 
When using side-mounted air outlets, or ceiling-mounted air outlets, the delivery air speed in winter must be above 2.5m/s to avoid the phenomenon of hot air staying and stagnating on the ceiling. Therefore, it is sometimes necessary to ensure that the ventilation frequency of the room is 5-8 times per hour. The air flow velocity in the area where people work and stay indoors should be controlled within the range of 0.5m/s. If the air outlet is installed at the upper part of the wall, when the air flow blows towards the beams or the decoration ceiling, it is necessary to move the position of the air outlet downward as much as possible, or use horizontally adjustable louvers to avoid the air flow hitting the beams.



The number of supply air outlets and return air outlets depends on the size of the room. For ordinary residential buildings, one supply and one return air outlet per room is sufficient when installing a home ventilation system. For medium-sized areas such as villas, living rooms, conference rooms, and offices, it is necessary to appropriately increase the number of air outlets. In ordinary homes, study rooms and other rooms can be installed according to actual use. In short, it is only necessary to meet the first requirement.
 
Toilet and kitchen have strong particularity. Both will produce highly polluted and humid gases in a short period of time. If supply air outlets are installed here, these polluted gases will be sent to other rooms. If return air outlets are installed here, these gases will be sent to the interior of the new air system, increasing the load of the new air system and affecting its effect. Therefore, it is recommended that neither supply nor return air outlets should be installed in the toilet and kitchen, but two independent exhaust fans should be installed.
 
It is recommended to install the living room supply air outlet in a location close to the pollution source, such as near the kitchen or near the door, and the return air outlet can be installed diagonally with the supply air outlet.


The number of supply air outlets and return air outlets depends on the size of the room. For ordinary residential buildings, one supply and one return air outlet per room is sufficient when installing a home ventilation system. For medium-sized areas such as villas, living rooms, conference rooms, and offices, it is necessary to appropriately increase the number of air outlets. In ordinary homes, study rooms and other rooms can be installed according to actual use. In short, it is only necessary to meet the first requirement.
 
Toilet and kitchen have strong particularity. Both will produce highly polluted and humid gases in a short period of time. If supply air outlets are installed here, these polluted gases will be sent to other rooms. If return air outlets are installed here, these gases will be sent to the interior of the new air system, increasing the load of the new air system and affecting its effect. Therefore, it is recommended that neither supply nor return air outlets should be installed in the toilet and kitchen, but two independent exhaust fans should be installed.
 
It is recommended to install the living room supply air outlet in a location close to the pollution source, such as near the kitchen or near the door, and the return air outlet can be installed diagonally with the supply air outlet.



In general, corridors and other areas do not require supply or return air outlets based on the room area. The ventilation conditions in the basement are poor, so both supply and return air outlets need to be installed. When installing, the location of the air outlets should be carefully considered according to the function of the basement.
 
The ground supply and ceiling return mode is more effective than the ceiling supply and return mode, but the ground supply and ceiling return mode requires higher ceiling height and the ground supply air outlet is easily polluted. Therefore, the wall exhaust air mode is recommended when using ground supply air.
 
The distance between supply air outlets and return air outlets should be as far as possible to achieve the purification effect.