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

When selecting a constant temperature and humidity air conditioning box, you should first clarify the service area, temperature and humidity setting range, allowed changes, representative load, operating period and measurement location. Simply writing 'constant temperature and humidity' cannot determine equipment capabilities because controlling temperature, controlling moisture, and responding to load changes are interrelated tasks.

First describe the actual changes in the production process

List the minimum and maximum conditions for heat and moisture dissipation of personnel and equipment, and indicate whether opening the door, exhausting air, and stopping and resuming the machine are included in normal working conditions. Then distinguish the air treatment undertaken by the unit and the distribution control completed by the room system. If there is independent environmental control inside the process equipment, it is necessary to avoid duplicating the same load into the air conditioning box.

The steady-state target should write down the setting and control range of temperature, humidity or moisture content; the changing working conditions should write down the production shift, process load, door opening and fresh air changes; the verification conditions should clearly define the measurement location, instrument, stabilization time and recording method. If one of the three is missing, the selection can only remain at a rough estimate. How to distribute the room load to the units, please refer toWhat indoor loads should the circulating air handling unit be selected based on?。

Controlling temperature and controlling moisture are two different things

Temperature control mainly relies on coil, heating and air supply volume adjustment, while humidity control involves cooling, dehumidification, humidification and reheating. In a constant temperature and humidity project, cooling and dehumidification may occur at the same time, and reheating will affect the supply air temperature. If only a target of 'temperature ±1°C and humidity ±5%' is given without specifying the corresponding working conditions and measuring points, the equipment configuration is prone to deviations. The difference between dehumidification capacity and cooling capacity can be referred toHow to calculate the dehumidification capacity of air conditioning box from the difference in air moisture content? ;For the relationship between dew point and moisture control, please refer toWhat role does the supply air dew point play in the selection of fresh air air conditioning boxes?。

Use multiple working conditions to verify program integrity

Summer dehumidification, winter humidification, and small loads in transition seasons may require different execution combinations. The equipment must not only have sufficient maximum capacity but also be adjustable at low loads. Technical data should separately describe the control objects and available energy sources to avoid using one rated cooling capacity to summarize the annual control tasks.

Adjustability at low loads is often overlooked. If the minimum output of the unit is much higher than the actual load, frequent starts and stops or temperature and humidity fluctuations may occur. When selecting, check the adjustable ranges of coils, heating, humidification and fans, and consider grading or bypass measures if necessary. For issues involving partial load operation, please refer toWhy should we check the efficiency range when selecting air-conditioning box fans?。

The measurement location and evaluation time must be agreed in advance

The 'accuracy' of constant temperature and humidity needs to correspond to specific measurement points and evaluation periods. The results of supply air measurement points, room measurement points and equipment internal measurement points may be different, and the stabilization time and sampling interval will also affect the conclusion. The project requirements should indicate whether to control air supply parameters or room parameters, and how to evaluate fluctuations, deviations and recovery times respectively. Please refer toWhat is the difference between air supply accuracy of air conditioning box and room control accuracy? andHow should the allowable fluctuations of constant temperature and humidity units be written into the technical requirements?。

Aili industrial supporting equipment

Aili Industrial can check the hot, cold and wet treatment and control packages based on the working condition table, and provide the load change range during project communication, which is more convenient for selection than only providing a target temperature and humidity. Aili Industrial can check the coil, heating, humidification, fan and control configurations together, and clarify the adjustment range and measuring point location of each execution component in the planning stage; the manufacturing end covers independent research and development and production of motors and fans, control systems, sheet metal, air filters and complete machine assembly. The hot and cold moisture treatment sections and control logic can be aligned in the same package.

Product form can be viewedAir handling unit andFan box page; clean air supply package can be combinedFFU fan filter unit andHEPA/ULPA filter verification; when it comes to gaseous pollution control, you can communicate separatelyChemical filter solutions. The specific control effect, applicable environment and delivery scope still need to be verified based on the corresponding configuration data and on-site working conditions. Actual results are subject to on-site leak detection and performance test results.

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

Related questions and answers

Can constant temperature and humidity selection be completed by just writing the temperature and humidity targets?
not enough. It is also necessary to explain the allowable changes, load range, operating period, measurement location and evaluation method, otherwise the equipment capability cannot correspond to the actual requirements.

Is the accuracy of the constant temperature and humidity air conditioning box a guaranteed value for the equipment?
Not exactly. The equipment provides control capabilities on the supply side, and room accuracy is also affected by airflow organization, load distribution, envelope structure and measurement point location.

Can Aili Industrial help sort out the constant temperature and humidity control objectives?
The cold, hot and wet treatment and control configuration can be checked based on load changes, working condition combinations and measuring point requirements. The specific plan needs to be confirmed based on project conditions.

Related articles

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

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

3. How to calculate the dehumidification capacity of air conditioning box from the difference in air moisture content?

4. What role does the supply air dew point play in the selection of fresh air air conditioning boxes?

Key points for selection and acceptance inspection