Square Swirl Diffuser

REF-SD

The REF-SD Series Square Swirl Diffuser is a high-efficiency ceiling air supply terminal device. Designed specifically for commercial spaces requiring high air volume, its swirling airflow pattern ensures rapid mixing and even distribution of air. Available in two models: REF-SD-A (supply only) and REF-SD-D (supply/return with adjustable blades). Suitable for ceiling heights of 2.6m to 4m, it comes in multiple sizes with a standard white or custom-color powder coating finish.

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Square Swirl Diffuser Ceiling Air Diffusers

High-performance square swirl diffusers for commercial HVAC systems, providing optimal air distribution and comfort.

About Square Swirl Diffusers

Square swirl diffusers are engineered HVAC components designed for efficient air supply and return in commercial ceiling applications. Our REF-SD series swirl diffusers create a swirling air pattern that ensures rapid mixing and uniform temperature distribution, making them ideal for spaces requiring high air volume and comfortable air diffusion.

REF-SD-A

Supply Swirl Diffuser

REF-SD-D

Supply/Return Swirl Diffuser

REF-SD-A Square Swirl Diffuser (Supply)

The REF-SD-A swirl diffuser is specifically designed as a ceiling supply air outlet. This square swirl diffuser is engineered for environments that demand high air volume delivery with effective diffusion.

Key Features & Applications:

Used as a supply diffuser on ceilings for optimal air distribution.

Ideal for spaces requiring high air volume, such as auditoriums and large halls.

Recommended for ceiling heights between 2.6m and 4.0m.

Accessories include plenum box and round slide damper for airflow control.

Standard finish: White powder coating (RAL9016, RAL9010), with custom colors available.

REF-SD-A Selection Table & Dimensions

Standard size (mm)	Effective Area (m²)	B (mm)	D (mm)	L (mm)	Q (mm)	H2 (mm)	K (mm)	Air volume (m³/h)
300x300	0.009	280	148	250	295	250	290	145-200
400x400	0.018	364	198	350	395	295	372	180-400
500x500	0.025	462	198	450	495	295	476	215-520
595x595	0.030	559	248	538	595	345	567	290-600
600x600	0.030	559	248	538	598	345	567	290-600
625x625	0.030	559	248	538	623	345	567	290-600

REF-SD-D Square Swirl Diffuser (Supply & Return)

The REF-SD-D series swirl diffuser offers versatile functionality for both supply and return air applications on ceilings. Featuring adjustable black plastic blades, this square swirl diffuser provides precise control over airflow direction and volume.

Key Features & Applications:

Used as both supply and return air diffuser on ceilings for complete air handling.

Equipped with adjustable black plastic blades for customizable airflow direction.

Recommended for ceiling heights between 2.6m and 4.0m.

Accessories include plenum box and round slide damper for system integration.

Standard finish: White powder coating (RAL9016, RAL9010), with custom colors available.

Available Models:

REF-SD-D1

Standard swirl diffuser

REF-SD-D2

High-capacity swirl diffuser

REF-SD-D5

Maximum air volume swirl diffuser

REF-SD-D Selection Table & Dimensions

Model	Standard size (mm)	B (mm)	D (mm)	L (mm)	Q (mm)	H2 (mm)	K (mm)	Air volume (m³/h)
REF-SD-D1	295x295-8	280	148	250	295	250	290	55-250
REF-SD-D1	395x395-12	364	198	350	395	295	372	100-400
REF-SD-D1	495x495-24	462	198	450	495	295	476	140-470
REF-SD-D1	595x595-28	559	248	538	595	345	567	250-730
REF-SD-D2	295x295-10	280	148	250	295	250	290	150-410
REF-SD-D2	395x395-12	364	198	350	395	295	372	170-490
REF-SD-D2	495x495-24	462	198	450	495	295	476	300-980
REF-SD-D2	595x595-48	559	248	538	595	345	567	360-1380
REF-SD-D5	595x595-32	559	248	538	595	345	567	420-1600

Applications for Square Swirl Diffusers

Commercial Buildings

• Office Buildings & Conference Rooms

• Shopping Malls & Retail Stores

• Hotels & Restaurants

• Banks & Financial Institutions

Public & Institutional

• Schools & Universities

• Hospitals & Healthcare Facilities

• Libraries & Museums

• Auditoriums & Theaters

Industrial & Specialized

• Manufacturing Facilities

• Laboratories & Clean Rooms

• Data Centers

• Sports Complexes & Gyms

Why Choose Our Square Swirl Diffusers?

Superior Air Distribution

Swirl diffuser design creates a circular air pattern for rapid mixing and uniform temperature distribution, eliminating drafts and cold spots.

High Air Volume Capacity

Engineered for spaces requiring substantial airflow, with capacities ranging from 55 to 1600 m³/h across different models.

Versatile Applications

Available in supply-only (REF-SD-A) and supply/return (REF-SD-D) configurations to meet diverse HVAC system requirements.

Adjustable Design

REF-SD-D models feature adjustable black plastic blades for precise control over airflow direction and pattern.

Aesthetic Integration

Clean square design with white powder coating (RAL9016/9010) or custom colors to blend seamlessly with modern ceiling designs.

Easy Installation & Maintenance

Compatible with standard plenum boxes and round slide dampers for straightforward integration into existing HVAC systems.

Technical Notes & Disclaimer

All dimensions are in millimeters (mm). Air volume ranges are indicative and may vary based on system pressure and installation conditions.
Ceiling height recommendation: 2.6m to 4.0m for optimal performance of the square swirl diffuser. Specifications subject to change without prior notice.

REF-SD Square Swirl Diffuser Support

Comprehensive warranty, technical support, installation guidance and FAQs for your ceiling air diffuser system

12-Month Warranty Coverage

We provide a 12-month warranty period for our REF-SD Square Swirl Diffusers, calculated from the date the customer receives the goods. During this warranty period, we will provide free repair services, including free replacement parts, for any failures caused by product material or workmanship quality issues.

12

Months Warranty

✓

Material & Workmanship

✓

Powder Coating Finish

Technical Support

We offer dedicated technical support for our REF-SD Square Swirl Diffuser range. Our engineers can assist with product selection, sizing calculations for optimal air distribution, installation guidance, and troubleshooting. Use the selection tables to choose the appropriate model based on your required air volume and ceiling space.

✉️

Email Support

sharon.pan@refria.com

Contact us for product selection, sizing, installation, or technical questions

⏱️

Response Time

Within 24 hours

(1 business day) for technical inquiries

For Efficient Support, Please Provide:

•

Product model (REF-SD-A or REF-SD-D1/D2/D5) and desired size

•

Required air volume (m³/h) and ceiling height

•

Application type (supply only or supply/return)

•

Desired finish color (standard white or custom RAL code)

Square Swirl Diffuser Frequently Asked Questions

What is the difference between REF-SD-A and REF-SD-D series square swirl diffusers?

The key difference lies in their application and features:

REF-SD-A Series

Primary Use: Supply air only

Ideal For: High air volume applications

Features: Fixed blade design for consistent air pattern

REF-SD-D Series

Primary Use: Both supply and return air

Ideal For: Versatile applications requiring airflow adjustment

Features: Adjustable black plastic blades for directional control

Both series are square swirl diffusers designed for ceiling mounting between 2.6m and 4.0m height, with white powder coating standard finish.

How do I select the right size square swirl diffuser for my space?

Selecting the correct square swirl diffuser size involves considering several factors:

1

Required Air Volume: Calculate the total airflow needed for the space (m³/h).

2

Ceiling Height: Our swirl diffusers are optimized for 2.6m to 4.0m ceilings.

3

Space Layout: Consider the room dimensions and diffuser placement for even air distribution.

4

Consult Selection Tables: Use the air volume ranges in our technical tables to match your requirements.

Professional Assistance Recommended

For complex projects, we recommend consulting with an HVAC engineer or using our technical support service for proper square swirl diffuser sizing and placement.

Can REF-SD square swirl diffusers be used with different plenum boxes?

Yes, our REF-SD Square Swirl Diffusers are designed to be compatible with standard plenum boxes. We offer plenum boxes and round slide dampers as accessories for complete system integration. The dimensions (B, D, L, Q, H2, K) provided in our selection tables ensure proper fit with standard HVAC ductwork and accessories.

Recommended Accessories

• Plenum box for air distribution

• Round slide damper for airflow control

• Mounting brackets (as required)

Installation Note

Ensure the plenum box is properly sealed and insulated to prevent air leakage and thermal losses. Follow local HVAC codes and standards for installation.

What are the available finish options for square swirl diffusers?

Our REF-SD Square Swirl Diffusers come with a durable white powder coating as standard. We offer two standard RAL colors, and custom colors are available upon request for larger projects.

RAL 9016

Traffic White

RAL 9010

Pure White

Custom

Any RAL Color

The powder coating provides excellent corrosion resistance and a smooth, easy-to-clean surface. For custom colors, please contact us with your RAL color code and minimum quantity requirements.

Important Technical Notes

All dimensions in selection tables are in millimeters (mm). Air volume ranges are indicative and may vary based on system static pressure and duct configuration.
Square swirl diffusers are designed for ceiling heights between 2.6m and 4.0m for optimal air diffusion performance. Ensure proper installation by qualified HVAC technicians.
Specifications subject to change without prior notice.