What is the reason for the noisy central air conditioning and how to solve it
It is said that the Daikin central air conditioner is "three-point quality, seven-point installation". This shows that the professional installation of workers is a major factor in the noise of the air conditioner. The air conditioner generates greater noise when it is used. In fact, these problems are usually easier. The solution lies mainly in the service attitude of the workers.
Solution:
1. The outdoor unit is improperly installed. First, find out the wall structure, such as precast concrete, and the indoor side is mostly office space or bedroom, study room, etc., it is relatively empty, and there will be whirl surround sound in the room. This is a building structure and a house. The interior decoration effect is produced, and this phenomenon is an objective factor condition.
2. The force of the screws on the bottom of the outdoor unit is uneven, and the fastening screws on the bottom plate are loose. When the compressor is running, the chassis should be vibrated to cause the chassis to jump to cause noise. Tighten the foot screws with a wrench and tighten them evenly. It is strictly forbidden to tighten one of the screws in place first, which will cause uneven fixing force.
3. The outdoor unit bracket is not installed horizontally, or the fixing screws of the combined bracket are not tightly deformed, which will cause the feet of the outdoor unit to be uneven. At this time, the outdoor unit bracket should be rearranged, the level should be adjusted or the bracket fixing screws should be tightened.
Second, compressor quality problems
The compressor is the heart of the central air conditioner. The quality of the compressor directly determines the noise level of the central air conditioner. The quality of the compressor directly controls the use effect of the Daikin central air conditioner. Many low-end central air conditioners use relatively inexpensive compressors because of cost control. Such a central air conditioner may be noisy when used.
Solution:
1. The performance of the compressor is poor, and a low-frequency vibration hum is generated during operation. The compressor can be adjusted and replaced.
2. The outdoor unit is too dirty, or there are foreign objects in the chassis, rubbing with the fan generates noise; it is enough to clean up the foreign objects.
3. It is caused by parts and components. It is common that the compressor stuck cylinder or compressor starting capacitor is damaged, and the damaged spare parts can be replaced.
Third, the wall thickness is not enough
In addition to the quality and installation process of the central air conditioner itself, the thickness of the wall where the external unit is installed is also a very important factor that affects the noise intensity. Some old houses have thin walls or hollow walls. When the air conditioner is turned on, it will cause resonance and generate low-frequency noise. The greater the power of the central air conditioner, the greater the relative noise. Therefore, when installing the central air conditioner, it is necessary to ask the installation worker to choose a thick wall to avoid the generation of greater noise.
Solution:
When the fan is running, it rubs against the outer wall, and the distance between the fan and the outer wall should be adjusted in time. In addition, it is also possible that the fan is stuck, add some lubricating oil to the fan shaft of the air conditioner to ensure that the fan rotates smoothly. Common failure maintenance method of central air conditioning system 1. Insufficient configuration of air conditioning cooling and heating load
1. Simply configure the cooling and heating load of the air conditioner according to the air conditioner use area
Due to the activity requirements of indoor personnel, for convenience, the door of the adjacent room will be opened frequently. If the room where the door is opened is not equipped with air conditioning (such as: kitchen room, toilet, dressing room, etc.), the cooling and heating load of the room will be The air-conditioning system forms a corresponding air-conditioning load, which leads to insufficient air-conditioning cooling and heating load configuration, and the temperature in the room is difficult to meet human comfort requirements.
2. The model room type is the same as the actual air conditioning cooling and heating load configuration
To meet the needs of sales, developers often display a complete decoration model for one or a few suites before the building is completed. However, the difference in the actual room type when the project is completed is ignored in the cooling and heating load configuration of the air conditioner.
3. The cooling and heating load configuration at the end of the air conditioner is sufficient, but since the simultaneous use factor of different rooms is considered to be less than 1, and the capacity of the air conditioning host is also configured according to the corresponding factor, then, when the air conditioner ends of all rooms are all turned on, the indoor temperature Will not meet the design requirements.
Second, the air conditioning cooling and heating load configuration is enough, but the effect is not good
1. The insufficient air volume of the air-conditioning return air system of the air duct machine makes the problem particularly prominent. The main reason is that the area of the return air pipe and the return air inlet is insufficient (unreasonable design). Rectification suggestions: Increase the size of the return air duct and return air outlet, or increase the return air duct and return air outlet.
2. The air supply and return air are short-circuited, that is, the air-conditioning air sent from the air supply port has not yet reached the air-conditioning area of the room, and then flows to the return air area.
3. For the sake of convenience and economy, the air pipe uses an overly long metal hose. When the wind speed in the metal hose is greater than 3m/s, the wind resistance in the pipe will increase rapidly, and the wind pressure of the indoor fan of the domestic central air conditioner is small. If its available wind pressure cannot overcome excessive resistance, its actual air volume will be much lower than the rated air volume.
3. During installation, the condensate pipe system is smooth, and dripping phenomenon is found during operation or after a period of operation
1. There is no spring washer at the upper and lower nuts of the boom when the indoor unit is suspended. When the device vibrates its nut during operation, the internal unit tilts in the opposite direction of the condensate tray, causing condensate to flow from the drip tray The upper mouth directly overflows.
2. The spacing of the condensate pipe support and hanger is too large, and the strength of the hanger is not enough; especially when there is no support hanger or the support hanger is too far from the elbow at the elbow where the horizontal pipe is connected to the riser. The riser pushes up, causing the condensate pipe to reverse. Therefore, when installing the air conditioning condensate pipe, we must pay great attention to the reliability of the pipe stiffness and slope.
Central air conditioning system maintenance and maintenance skills In recent years, my country's national economy has developed vigorously, people's living standards are increasing day by day, and the requirements for the living environment are becoming higher and higher, making central air conditioning widely used and popularized in some high-level areas. For example, large-scale supermarkets, high-rise financial buildings, office buildings, and tourist buildings, and other entertainment venues; there are also some science, education, cultural and health buildings, such as large libraries, science and technology museums, and gymnasiums; as well as medical and health, communication buildings, such as telecommunications equipment rooms, and There are transportation, such as the waiting hall of the airport, the waiting room of the bus station of the railway station, the subway station and so on.
Nowadays, with the continuous development of science and technology, people and production have some requirements for the temperature, humidity, flow speed and cleanliness of the air. The central air conditioning system occupies an important position in the production of human life. However, there are some problems in the management of the central air conditioning system. Many air conditioners can be operated normally for the first few years after being delivered for use. With the passage of time, the problems of the air conditioning system have gradually become prominent, and the following problems generally exist: cooling capacity Gradually weakening, the air volume is getting smaller and smaller, the noise of the air conditioning unit is gradually increasing, the effect of the fresh air system has not reached the best effect, the unit frequently fails, and the energy consumption is gradually increasing. There are many reasons for the above, but the main reason There is no good repair and maintenance of the air conditioner.
1. Basic concepts of central air conditioning
Central air conditioning refers to the indoor temperature, humidity, cleanliness and airflow speed, after the relevant processing of the air conditioning equipment is transported to each required zone, in order to meet the comfort of people's daily life or work, and Environmental engineering technology required for production process.
2. Operation management of central air conditioning system
2.1 Daily maintenance of refrigeration host
2.1.1 Some preparations before the official operation
Commonly used central air conditioning refrigerators have the following four models: one is a centrifugal refrigerator, the other is a screw refrigerator, the third is a piston refrigerator, and the fourth is an absorption refrigerator. The above four machines are completely sealed, and the sealed parts of the machine need to be carefully checked, identified and adjusted before being put into use. For each part of the measuring instruments, such as pressure gauges, thermometers, vacuum gauges and oil pressure gauges, etc. The instruction part is adjusted to ensure its accuracy. For specific preparations and work, it is best to refer to the instruction manual of the refrigeration unit provided by the manufacturer, and carefully prepare for the operation before operation to ensure that the machine can operate normally [1].
2.1.2 Regular maintenance
Refrigerator is the core equipment of the central air-conditioning system, so its maintenance needs to invite equipment manufacturers to regularly come for professional repair and maintenance, or you can sign a maintenance contract with the manufacturer to ensure that the repair of the refrigerator is qualified.
2.2 Daily maintenance of air conditioning unit
The main point of air conditioning unit maintenance is to check the blower, air filter, heat exchange coil and automatic regulating valve. The specific operations are: ○1 Blower: Clean the impeller, add lubricating oil to the bearing regularly, replace the damaged bearing in time, and check and replace the belt. At the same time, the basic screw of the blower must be tightened to ensure its firmness. ○2 Air filter: generally clean it once a month or so. When cleaning, pull out the filter and use a dry soft brush to filter the dust on the net. It can also be cleaned with clean water to filter the dust on the net. Let it dry before using it in the air conditioner. For environments with a lot of dust, the filter should be cleaned more often to prevent the filter from getting too much dust and affecting the ventilation of the air conditioner. ○3 Heat exchange coil: Clean the air conditioning refrigeration coil every year before entering the next air-conditioning season, and then check the coil for water leakage, and check the cold water inlet and outlet valves for water leakage. ○4 Automatic regulating valve: It is necessary to carefully check whether the operation of the automatic regulating valve is normal.
2.3 Daily maintenance of cooling tower
During the operation of the cooling tower, we must first carefully check the operation status of each part. The inspection mainly has the following key points: ensure that there are no other objects obstructing the air circulation on the air inlet louvers and the fan protective cover; there is no water leakage in each piping joint and valve, It can be operated flexibly; the water level of the water collecting plate should be moderate, and there is no phenomenon of water shortage or overflow; the action of the float valve should be flexible and the water output is normal; the fan runs relatively smoothly without abnormal noise or vibration; the elasticity of the fan belt should be suitable There is no obvious wear, such as excessive wear, it should be replaced and adjusted in a timely manner; there is no clogging in the hole of the water distributor; the water flow is more uniform through the packing layer, and there is no bias.
2.4 Daily maintenance of water pump
The daily management of the pump mainly includes the following aspects: check whether the temperature rise of the motor is normal and ensure that there is no odor; there is no leakage of the shaft seal; there is no abnormal noise and vibration; there is no leakage of the pipe fittings and valves; each valve opening position It needs to be suitable; the bearing is not short of oil, and the temperature is guaranteed to meet the specified requirements; the vibration reduction of the basic vibration reduction device and the soft joint of the water inlet and outlet achieves good results [2].
2.5 Daily maintenance and maintenance of fan coil
○1 Clean the return air filter every other month or so to ensure it is clean.
○2 Check the drip tray for clogging every February and March, and rinse with clean water.
○3 Always check whether the fan switching is normal to ensure that there is no vibration.
○4 Always check whether the control of the panel and solenoid valve is flexible.
2.6 Inspection and repair work of pipeline
The pipeline should be inspected regularly. If the pipeline is damaged or leaked, it must be repaired in time. As the temperature of the air-conditioning water changes in winter and summer, the expansion and contraction of the pipeline are relatively large, and the connection part of the pipeline is easily broken, resulting in water leakage. The deformation or rupture of the pipes around the air-conditioning unit is particularly important, and must be the key inspection object. There are many air-conditioning pipelines and relatively long pipelines. The thermal insulation status of the pipelines should be taken as the key inspection part. The thermal insulation layer should be checked frequently for damage or shedding. Valves on hot water or steam pipes must be regularly inspected and tested for leaks. In addition, each type of pipe in the air-conditioning system should be painted with different marks according to the regulations in order to make a distinction. It is also necessary to clean and drain the pipeline regularly [3].
2.7 Maintenance and maintenance of air duct system
Maintenance of air duct system mainly includes the following aspects:
○1Whether the insulation layer of the air duct is damaged or falls off, especially the part that is in contact with the hanger, whether there is glue or cracks at the interface.
○2 The pipeline must be sealed without air leakage, especially the joint of the pipeline, the joint of the unit and the soft joint of the air pipe, and the outside of the rotary shaft of the air valve.
○3 The air valve needs to be cleaned and lubricated. The adjustment of the air valve must be flexible, the positioning must be correct, stable and firm, and the indication angle of the electric air valve must be consistent with the opening angle of the valve.
○4 The tuyere should be cleaned.
○5 Make sure that there is no breakage and deformation, vibration and rust on the supporting objects [4].
2.8 Cooling water quality management
Because the cooling tower mechanism is open, usually some dust, dirt and rainwater will enter it. Therefore, measures must be taken to prevent the cooling tower from being contaminated. The water filter must be cleaned regularly to avoid debris falling into the condenser and causing blockage of the pipeline; the cooling water should be softened water, and the water quality needs to be regularly tested. If the water quality exceeds the standard, the cooling water of the system must be replaced, and appropriate descaling agent, corrosion inhibitor and algaecide should be added according to the requirements [5].
2.9 Start and stop sequence
The sequence of starting and stopping must be strict. The sequence of starting up is: chilled water pump → cooling water pump → cooling tower → chiller unit → air conditioner. The sequence of shutdown is: chiller→cooling pump→cooling tower→frozen water pump→air conditioner.
2.10 Other matters needing attention
Check carefully whether the hot water and steam thermal parameters of the external pipe network meet the design requirements. Each temperature-controlled three-speed switch should not set the temperature as frequently as possible. The three-speed switch is usually set in the mid-range position. In the heating season, the set point of the thermostat should be as low as possible; while in the cooling season, the set point of the thermostat should be higher. For hotel room air-conditioning system management, it should try to avoid the smell of the previous batch of passengers in the room affecting the favorite group of passengers. When there is no one in the room, the fan coil should be turned off but the fresh air system cannot be turned off. Avoid mildew in the room. During the transition season and the night of summer, when the outdoor air temperature is relatively low, the outdoor air can be adopted to cool the outdoor air. In summer and winter, when the air conditioner is needed for cooling or heating, the adjustment valve on the fresh air system pipe should be adjusted, and the opening degree of the adjustment valve should only meet the minimum fresh air volume, so as to reduce the cooling and heating load required by the fresh air; conditional Can use a full heat exchanger. In addition, the energy consumption and cost of each month should be provided to the operation management technicians, so that the management personnel understand the energy consumption, so that the management personnel can effectively formulate the next month's operation indicators.
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