What is the difference between air supply accuracy of air conditioning box and room control accuracy?

The air supply accuracy of the air conditioning box describes the air control performance of the specified measuring points of the unit, while the room control accuracy is also affected by air flow distribution, local load, enclosure, door opening and measuring point layout. The two should be specified separately, and the stability of the temperature and humidity at the air outlet cannot be directly equated to the stability of the entire room.

Separate three measurements that are often used interchangeably

A single air supply probe reflects local measurement, multiple room measurement points reflect spatial distribution, and the trend over a period of time reflects time fluctuations. When comparing options, clarify whether accuracy refers to instrument error, control deviation, or area uniformity. If these definitions are different, even if the values ​​are the same, they are not directly comparable.

For the air supply measurement points, the specified location, working conditions and unit control objectives must be written; for the room measurement points, the specified service area, layout and spatial difference evaluation must be written; for the time conditions, the specified steady state, sampling interval and recording period must be written. The three items correspond to different evaluation objects and cannot just be given a precision number. What control objectives should be clarified when selecting a constant temperature and humidity air conditioning box? Please refer toWhat control objectives should be clarified when selecting a constant temperature and humidity air conditioning box?。

Air supply accuracy is the control performance of the unit outlet

Air supply accuracy usually refers to the deviation range of the air supply temperature or humidity relative to the set value of the unit under agreed working conditions. It is affected by coil regulation, valve response, fan stability and sensor accuracy. Good air supply accuracy means that the air condition at the outlet of the unit is stable, but it does not mean that the same accuracy is achieved everywhere in the room.

How to select the type of surface cooler according to the air inlet and outlet conditions, please refer toHow to select the type of air conditioner cooler according to the air inlet and outlet conditions? . How does the position of the supply air temperature sensor affect the reading? Please refer toHow should the air supply temperature sensor of the air conditioning box avoid the influence of local airflow?。

Room accuracy is also affected by airflow distribution and load distribution

Room control accuracy describes the deviation range of temperature and humidity in the service area relative to the set value. In addition to being affected by the air supply status of the unit, it is also affected by air flow organization, local heat sources, enclosure structures, door opening frequency and personnel activities. The air supply accuracy is high, but if the air flow is unevenly distributed or the local load is concentrated, some areas of the room may still deviate from the target.

How the circulating air handling unit bears the indoor load can be referred toWhat indoor loads should the circulating air handling unit be selected based on? . The panel shows how the air-conditioning box in the workshop copes with large-area air supply zones. Please refer toHow does the panel display air-conditioning box in the workshop deal with large-area air supply zones?。

The location of the measuring point determines whether the 'accuracy' can represent the whole

The air supply accuracy corresponds to fixed measurement points, and the room accuracy corresponds to multiple measurement points or evaluation areas. If there is only one measuring point in the room, the reading at that measuring point may be affected by local airflow and may not represent the entire room. If the supply air measurement point is close to the coil outlet, the readings may be biased towards local conditions. Accuracy requirements should indicate the location and number of measuring points.

Whether the air conditioning box return air measurement points can represent all service areas, please refer toCan the air conditioning box return air measurement points represent all service areas? . Mixing section length and air flow uniformity, please refer toHow long is the air mixing distance required in the mixing section of the air conditioning box?。

The technical agreement should be written separately for the two types of precision.

The technical agreement should separately stipulate the air supply accuracy and room accuracy, indicating the respective measuring points, working conditions, allowable deviations, evaluation period and detection methods. You cannot just write 'control accuracy ± a certain value' without specifying whether it is air supply or room. The boundaries of responsibility between the two types of accuracy should also be clearly stated: the unit is responsible for the air supply output, and the room effect needs to be guaranteed by the system design and site conditions.

Please refer to how the allowable fluctuations of constant temperature and humidity units should be written into the technical requirements.How should the allowable fluctuations of constant temperature and humidity units be written into the technical requirements? . What applicable standards should be listed in the technical documents for purchasing air-conditioning boxes? Please refer toWhat applicable standards should be listed in the technical documents for purchasing air-conditioning boxes?。

From division of responsibilities to joint debugging

The unit is responsible for achieving the agreed air treatment output, and the room effect needs to be verified together with the air duct end, load and control strategy. If there is a local deviation, you should first compare the air supply and regional trends, and then check the distribution and load. It is not appropriate to directly attribute all room deviations to unit control problems. The technical agreement needs to outline verifiable boundaries for both parties.

How to debug the air-conditioning box from stand-alone to system linkage, please refer toHow to change the debugging sequence of air conditioning box from stand-alone unit to system linkage? . How to calibrate the temperature and humidity sensor, please refer toHow to determine the installation and calibration requirements for air conditioning box temperature and humidity sensors?。

Aili industrial supporting equipment

When confirming the constant temperature and humidity configuration with Aili Industrial, the air supply requirements and room goals can be provided separately to facilitate the clarification of the equipment output and the conditions that need to be completed by the system parties. Aili's industrial manufacturing end covers independent R&D and production of motors and fans, control systems, sheet metal, air filters and complete machine assembly. Coils, humidification sections, sensors and control logic can be matched in the same package; non-standard control requirements can be adjusted according to project accuracy indicators.

Product form can be viewedAir handling unit andFan box page; clean air supply package can be combinedFFU fan filter unit andEFU equipment end fan filter unit verification; terminal particle filtration can be combinedHEPA/ULPA filter confirmation; when it comes to gaseous pollution control, you can communicate separatelyChemical filter solutions. Specific accuracy indicators, control boundaries and delivery scope still need to be verified based on corresponding configuration data and on-site working conditions. The actual effect is subject to on-site debugging and performance test results.

Submit project parameters:https://ailigy.com/contactus.html

Related questions and answers

If the air supply accuracy is high, will the room accuracy also be high?
uncertain. Room accuracy is also affected by airflow distribution, local loads, enclosures and door openings. Stable air supply does not mean stability throughout the room.

Is it okay to only write a control accuracy in the technical agreement?
Not recommended. The air supply accuracy and room accuracy should be specified separately, and the measuring points, working conditions, allowable deviations and evaluation methods should be noted.

Can Aili Industrial help differentiate between air supply accuracy and room accuracy?
The two types of accuracy requirements can be checked based on the control objectives, measuring point locations and system division of labor. Specific indicators need to be confirmed based on project conditions.

Related articles

1. What control objectives should be clarified when selecting a constant temperature and humidity air conditioning box?

2. How should the allowable fluctuations of constant temperature and humidity units be written into the technical requirements?

3. Can the air conditioning box return air measurement points represent all service areas?

4. How to determine the installation and calibration requirements for air conditioning box temperature and humidity sensors?

Key points for selection and acceptance inspection