Understanding Central Air Conditioning Diffusers

Central air diffusers are terminal devices used for air supply and return in central air conditioning systems, serving as air distribution equipment. The supply diffuser delivers cooled or heated air into the room, while the return diffuser draws back the indoor stale air, forming the complete air circulation. This ensures both effective indoor cooling and heating and maintains indoor air cooling and comfort.

Types and Functions

1. Double-layered louvered Diffusers

Features:

• Function: Primarily used as supply diffusers, they can also be paired directly with fan coil units. Widely employed at the end of centralized air conditioning systems.
• Compatibility: Can be used in conjunction with multi-leaf regulating valves to adjust airflow.

2. Single-layered louvered Diffusers

Features:

• Adjustable Direction: Single-layered louvers allow for adjustable upward and downward airflow. Return diffusers can be used in conjunction with filter screens, and the angle of the blades can be adjusted.
• Construction: Equipped with ABS plastic fixed brackets between the blades.

3. Fixed Bar Diffusers

Features:

• Application: Used in both heating and cooling air conditioning systems, can be installed on side walls or ceilings.

4. Self-Dropping Louvered Air Diffusers

Features:

• Automatic Exhaust: These diffusers are designed to automatically exhaust air from air-conditioned rooms under positive pressure conditions.
• Louver Mechanism: Typically, the louvers of these diffusers are designed to naturally droop under their weight, effectively sealing off the exchange of air between indoors and outdoors.
• One-way Flow: When the indoor air pressure exceeds the outdoor pressure, the airflow pushes the louvers open to exhaust air outside. Conversely, when the indoor air pressure is lower than the outdoor pressure, the airflow prevents reverse flow into the room, serving as a one-way valve.

5. Dispersal Diffusers

Features:

• Versatile Design: Dispersal diffusers are commonly used in HVAC systems and can be crafted into square or rectangular shapes to suit various ceiling designs.
• Detachable Core: The core of these diffusers can be detached from the outer frame, facilitating easy installation and cleaning.
• Adjustable Airflow: They can be equipped with airflow adjustment valves at the back to regulate airflow volume.
• Applications: Suitable for a wide range of spaces including broadcasting studios, hospitals, theaters, classrooms, concert halls, libraries, arcades, theater lounges, offices, shops, hotels, restaurants, and sports arenas.

6. Adjustable Ball Diffusers

Features:

• Jet Nozzle Design: These diffusers feature a nozzle-type design for directing airflow in specific directions.
• Adjustable Direction: Airflow direction can be easily adjusted within a conical space with a 35° apex, allowing for precise control over the direction of airflow.
• Flow Control: The flow rate can also be adjusted by modulating the valve opening.
• Applications: Primarily used in spaces requiring high-speed airflow or localized cooling, such as airport terminals, indoor sports arenas, hotel kitchens, etc.

7. Swirl Diffusers

Features:

• Rotating Jet Stream: Swirl diffusers emit a rotating jet stream with high induction and rapid velocity decay characteristics.
• Reduced Number of Diffusers: They are suitable for high-volume, high-temperature differential airflow applications, enabling a reduction in the number of diffusers required.
• Installation: Installed on ceilings or suspended from them, they can be used in spaces with ceiling heights of up to 3 meters or in configurations for expansive, high-volume airflow, reaching heights of over 10 meters.

Standard Sizes:

The size of air diffusers depends on the capacity of the indoor unit. If the diffuser is too large and the duct is too long, the airflow velocity decreases, affecting the effectiveness of air conditioning. Conversely, if the diffuser is too small, the airflow velocity increases, leading to discomfort caused by direct airflow onto individuals and potentially excessive noise.

Material Options:

Air diffusers available in the market are primarily made of ABS plastic or aluminum alloy. In some cases, custom wooden diffusers are used for decorative purposes.

ABS Plastic Diffusers: These diffusers have a higher dew point and are less prone to condensation, but they tend to be more expensive.

Aluminum Alloy Diffusers: These diffusers are more prone to condensation but are relatively cheaper.

Installation of Air Diffusers:

Proper installation is a crucial aspect of central air diffusers. Generally, it’s advisable to install diffusers before painting. This ensures that even if the wall surface is accidentally marred during installation, it won’t pose a significant problem. Additionally, there is typically a gap between the louvers and the wall. Installing the diffuser before painting allows for the gap to be filled with paint, achieving a seamless integration.

Considerations for Central Air Diffuser Installation:

1. Avoidance of Light Troughs: It’s best not to install light troughs at the location of air diffusers, as they can obstruct the flow of warm air to the occupied areas, thus affecting the heating efficiency.
2. Optimal Louver Angle: Based on experience and experimental data, adjusting the louvers to a 45-degree angle during heating in winter is deemed most suitable. Angles that are too high or too low may adversely affect heating efficiency.
3. Maintenance: Central air diffusers tend to accumulate dirt due to the large airflow, affecting both the temperature of the air and the aesthetics. Users should regularly clean the diffusers to maintain cleanliness and ventilation.

Achieving Optimal Performance of Central Air Diffusers:

To ensure the best performance of central air diffusers, several factors need to be considered:

1. Selecting the Right Type of Diffuser:
   • Modern design trends favor minimalist diffusers. Options include narrow-framed diffusers (with frame widths of approximately 1.0cm or 1.5cm), frameless recessed diffusers, or gypsum board embedded diffusers.
2. Considering Diffuser Placement:
   • Install diffusers in the center of the room, maintaining a certain distance from walls or obstacles to ensure proper air circulation and even distribution.
3. Adjusting Diffuser Angles:
   • Depending on the specific room conditions and requirements, adjust the diffuser angles appropriately to direct airflow into the room at comfortable angles.
4. Regulating Airflow:
   • Adjust the airflow of the central air conditioning system according to room size and occupancy density to meet comfort requirements.
5. Temperature Control:
   • Maintain appropriate indoor temperatures to conserve energy.
6. Regular Cleaning:
   • Ensure diffusers are kept clean and unobstructed by removing dust and impurities regularly.
7. Choosing the Right Material:
   • ABS material diffusers are recommended as they are less prone to condensation.
8. Considering Color and Design:
   • The diffuser color should match the interior decor. Internally, elongated diffusers can be painted black to maintain consistency.
9. Considering Size and Installation Method:
   • Choose diffuser lengths according to the length of the suspended ceiling. When diffusers are elongated, fake diffusers should be painted black or made of black material.
10. Considering Installation Method:
    • Common installation methods include side supply and bottom return, side supply and side return, and bottom supply and bottom return. Choose the installation method that suits the room layout and requirements.
11. Coordinating with Light Troughs:
    • Avoid placing light troughs or obstructions in front of diffusers to prevent airflow distribution blockages.

By following these recommendations, the optimal performance of central air diffusers can be ensured.

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