1. Fresh air system.
The fresh air system can still introduce outdoor fresh air under the premise of not opening windows for 24 hours to eliminate indoor turbid and harmful air. The fresh air system consists of a fan, an air inlet, an air outlet and various pipes and joints. The fan installed in the suspended ceiling is connected with a series of air outlets through pipes. The fan is started. The indoor polluted air is discharged to the outside through the air outlet and the fan to form negative pressure in the room, outdoor fresh air will enter the room through the air inlet, so that indoor personnel can breathe high quality fresh air, which is the fresh air system.
The imbalance of positive and negative pressure leads to air flow. Generally speaking, it is based on sending fresh air to the room with special equipment on one side of the sealed room, and then discharging it to the outside by special equipment on the other side, thus forming a "fresh air flow field" indoors, thus meeting the needs of indoor fresh air ventilation.

2. Fan coil works.
Fan coil unit is the most widely used terminal equipment in central air conditioning system. The full name of fan coil unit is central air conditioning fan coil unit. The air outlet of the local ceiling of the room hides the fan coil unit. The fan coil unit keeps bringing us comfortable temperature.
(1). Classification of fan coil control schemes.
Fan coil control mostly adopts local control scheme, which is divided into simple control and temperature control:.
Fan coil simple control: the use of three-speed switch direct manual control fan three-speed conversion and start and stop.
Fan coil temperature control: the thermostat is used to automatically control the opening and closing of the electric two/three-way valve, the three-speed conversion of the fan, or directly control the three-speed conversion and start-stop of the fan according to the comparison between the set temperature and the actual detected temperature, so as to achieve a constant temperature by controlling the water flow or air volume of the system.
(2) composition of fan coil.
The fan coil is mainly composed of a fan, a heat exchange coil and a casing. According to the external static pressure of the fan coil machine, it can be divided into standard type and high static pressure type. According to the number of heat exchange coil rows, it can be divided into two rows and three rows. The heat exchange coil generally adopts copper tube string aluminum fins. The outer diameter of the copper tube is 10~16mm, the fin thickness is about 0.15~0.2mm, and the spacing is 2.0~3.0mm, the motor adopts capacitive 4-pole single-phase motor, three-speed speed, and the casing and fan coil condensate tray are insulated.
(3) The working principle of fan coil air conditioning system.
With the help of fan coil units, the indoor air is continuously circulated to be cooled or heated through the coil to maintain the required temperature and certain relative humidity of the room. The cold water or hot water used by the coil is supplied by centralized cold source and heat source. At the same time, the fresh air after centralized treatment by the fresh air conditioning room is sent to each air conditioning room through special fresh air pipes to meet the sanitary requirements of the air conditioning room.
Compared with the centralized system, the fan-coil air-conditioning system has no large wind channel, only water pipes and smaller fresh air pipes. It has the advantages of convenient layout and installation, small building space occupation, and good individual adjustment. It is widely used in temperature and humidity accuracy requirements. It is not high, the number of rooms is large, the rooms are small, and the comfort air conditioner needs to be controlled separately.
The working principle of fan coil is not as complicated as that of central air conditioning. In fact, we can regard the image of fan coil as an electric fan, but the air blown by this electric fan is the temperature we need. At present, there are many fan coil units on the market. In order to save costs, many companies will choose domestic fan coil units instead of imported central air conditioning hosts, which will not affect the operation and use effect of the entire central air conditioning system.
When cleaning the fan coil, dust cleaning is often ignored. Many people's cleaning work is not very detailed. Here is a reminder that dust has a great influence on the use effect of the fan coil. It is very important for his cleaning. Let's take a look at it slowly:.
The fan coil is responsible for the important mission of transferring the cold heat of hot and cold water to the air passing through the fan coil. In order to ensure high efficiency heat transfer, the surface of the fan coil must be kept smooth as much as possible. However, because the fan coil is generally equipped with coarse filters with relatively large holes, dust will inevitably pass through the filter and adhere to the pipe or fin surface of the coil when it is first used, if it is not cleaned in time, the heat exchange between the hot and cold water in the coil and the air flowing out of the coil will be reduced, so that the heat exchange efficiency of the coil can not be fully exerted. If there is a lot of dust attached, even some air passages between the fins are blocked, the air supply volume of the fan coil will be reduced, and the air conditioning performance will be further reduced.
Shandong Xingheng Environmental Technology Group Co., Ltd. is located in Luquantun Development Zone, Dezhou, Shandong Province, the hometown of glass fiber reinforced plastic in China. The company has three-level qualification for construction mechanical and electrical installation engineering, three-level qualification for environmental protection engineering, and safety production license. It is the first in the industry to pass ISO9001 quality management system certification, ISO14001 environmental management system certification, OHSAS18001 occupational health management system certification, an axial fan invention patent, a fan utility model patent, EIA, three at the same time waiting for complete procedures