Are you struggling to choose between a DIDW centrifugal fan and an SISW centrifugal fan? Wondering which design delivers superior airflow, lower noise levels, or a more compact footprint? Curious about how each type performs under varying pressure and energy demands?
DIDW centrifugal fans feature two inlet ports and double-width impellers for higher flow rates and pressure, whereas SISW centrifugal fans use a single inlet and single-width design for a more compact size and simpler maintenance.
In this article, readers will explore the core principles of DIDW and SISW fan construction, performance metrics, and selection criteria—continue reading to discover which centrifugal fan will optimize your application’s efficiency and reliability.
- What is DIDW Centrifugal Fan?
- What is SISW Centrifugal Fan?
- Advantages of DIDW Centrifugal Fan
- Advantages of SISW Centrifugal Fan
- DIDW Centrifugal Fan VS SISW Centrifugal Fan
- DIDW Centrifugal Fan Vs SISW Centrifugal Fan Price
- Conclusion
1. What is DIDW Centrifugal Fan?
DIDW stands for "Double Inlet Double Width."
A DIDW centrifugal fan is a type of fan that has two inlets and a double-width impeller, which allows it to move a large volume of air at relatively high pressures.
It is often used in industrial and commercial applications where a large volume of air needs to be moved, such as in HVAC systems or in process cooling.
DIDW centrifugal fans are known for their high efficiency and low noise levels, and they are often used in applications where these factors are important.
2. What is SISW Centrifugal Fan?
SISW stands for "Single Inlet Single Width."
A SISW centrifugal fan is a type of fan that has a single inlet and a single-width impeller, which allows it to move a moderate volume of air at relatively low pressures.
It is often used in small to medium-sized applications where a moderate volume of air needs to be moved, such as in residential HVAC systems or in small industrial processes.
SISW centrifugal fans are known for their simplicity, low cost, and ease of maintenance, and they are often used in applications where these factors are important.
3. Advantages of DIDW Centrifugal Fan
There are several advantages to using a DIDW centrifugal fan:
High efficiency
DIDW centrifugal fans are known for their high efficiency, which means they are able to move a large volume of air with relatively low power consumption.
Low noise levels
DIDW fans typically operate at lower noise levels compared to other types of fans, making them suitable for use in noise-sensitive applications.
High pressure
DIDW fans are able to generate relatively high pressure, which makes them suitable for use in applications where a high pressure drop is required, such as in air handling systems.
Versatility
DIDW fans can be used in a wide range of applications, including HVAC, process cooling, and ventilation.
Long lifespan
DIDW fans are known for their long lifespan, which means they can be used for many years without requiring frequent maintenance or replacement.
4. Advantages of SISW Centrifugal Fan
There are several advantages to using a SISW centrifugal fan:
Low cost
SISW fans are typically less expensive to manufacture and purchase compared to other types of fans, making them a cost-effective choice for many applications.
Ease of maintenance
SISW fans have a simple design and are easy to maintain, which makes them suitable for use in applications where maintenance may be required on a regular basis.
Compact size
SISW fans are typically smaller and more compact than other types of fans, making them suitable for use in space-restricted applications.
Versatility
SISW fans can be used in a wide range of applications, including HVAC, ventilation, and process cooling.
Reliability
SISW fans are known for their reliability, which means they can be relied upon to operate consistently over time without requiring frequent maintenance or repair.
5. DIDW Centrifugal Fan Vs SISW Centrifugal Fan: Which One Suit You
The choice between a DIDW centrifugal fan and a SISW centrifugal fan will depend on the specific requirements of the application. Here are a few things to consider:
| Criteria | DIDW Centrifugal Fan | SISW Centrifugal Fan |
| Volume & Pressure | High flow rates and high pressure thanks to two inlets and double-width impeller | Moderate flow at lower pressure with single inlet and single-width impeller |
| Size & Space Constraints | Larger footprint; requires more installation space | Compact design; ideal for tight spaces |
| Cost | Higher upfront cost | Generally more affordable |
| Noise | Quieter operation due to balanced double-inlet design | Potentially higher noise levels |
| Maintenance | More complex upkeep | Simpler design; easier and quicker to maintain |
Volume and pressure
If you need to move a large volume of air at high pressure, a DIDW fan may be a better choice. If you only need to move a moderate volume of air at low pressure, a SISW fan may be sufficient.
Size and space constraints
If space is limited, a SISW fan may be a better choice due to its compact size. If space is not an issue, a DIDW fan may be a more suitable option.
Cost
SISW fans are generally less expensive than DIDW fans, so if cost is a major consideration, a SISW fan may be the better choice.
Noise
If noise levels are a concern, a DIDW fan may be a better choice due to its low noise levels.
Maintenance
If ease of maintenance is important, a SISW fan may be the better choice due to its simple design and ease of maintenance.
It is worth noting that both DIDW and SISW fans have their own advantages and are suitable for different applications. Ultimately, the best choice will depend on the specific requirements of the application.
6. DIDW Centrifugal Fan Vs SISW Centrifugal Fan Price
When it comes to upfront investment, Single Inlet Single Width (SISW) fans generally carry a lower purchase price than Double Inlet Double Width (DIDW) models.
Typical list prices for industrial-grade SISW fans range from $1,000 to $3,000, depending on size and motor power, whereas comparable DIDW units often start around $2,500 and can exceed $5,500 for high-capacity configurations.
This premium reflects the more complex impeller geometry, heavier-duty bearings, and larger housings required for double-width, double-inlet performance.
However, selecting solely on sticker price may overlook lifecycle cost impacts. DIDW fans—despite their higher initial cost—often deliver greater airflow per watt, reducing energy expenditure by 5–15% annually in high-demand applications.
When evaluated over a 5-year service period, the energy savings and reduced downtime can offset the price differential, making DIDW the more economical choice for large-scale or continuous-operation systems.
Conclusion
In summary, both DIDW and SISW centrifugal fans offer distinct advantages tailored to different operational needs.
SISW fans excel in compact installations and budget-conscious projects, delivering reliable airflow with straightforward maintenance and lower upfront costs.
DIDW fans, while more expensive initially, provide superior static pressure, enhanced energy efficiency, and quieter operation—benefits that compound over the fan’s service life in demanding or continuous-duty environments.
By carefully evaluating installation constraints, performance requirements, and total lifecycle costs, decision-makers can confidently select the centrifugal fan solution that best aligns with their application goals.
Langdi is a leading centrifugal fan manufacturer in China, which can provide high-quality centrifugal fans, axial fans and other products. If you have customized needs, welcome to contact us for more information, we always provide you with the best products and services.
