What is a Centrifugal Cooler?
An industrial centrifugal cooler is a type of evaporative cooling system. This device uses the rotation of its centrifugal fan blades to draw a huge volume of air in at high pressure. The incoming air then passes through moist pads (usually cellulose pads). As the dry air moves over the wet pads, the water in the pads evaporates, which lowers the air temperature. The cooled air is then powerfully blown into the desired space by the cooler’s fan, significantly reducing the temperature.
These coolers are considered very powerful cooling systems and have a high capacity for cooling industrial areas and large spaces. Due to its high efficiency and optimal performance, the centrifugal cooler can easily meet the cooling needs of large industrial and commercial facilities.
Technical Specifications and Key Features of the Centrifugal Cooler
The centrifugal cooler has specific features that make it suitable for heavy-duty applications:
Ducting Capability: This feature allows for the distribution of cool air to different parts of a building or a warehouse. The centrifugal cooler’s high-pressure distribution capability lets it effectively guide air through ducts. Proper ducting is essential for its installation and setup.
Durable Body Material: The body is typically made from high-gauge galvanized sheet metal. Some models use galvanized sheet metal with a thickness of 1.5 mm, which provides high resistance and durability for use in industrial and workshop environments.
Electrostatic Paint Coating: This coating has a high thickness and provides strong resistance against moisture, corrosion, and direct sunlight.
Evaporative Media: Dadman Tahvieh centrifugal coolers use cellulose pads instead of conventional aspen pads (wood wool). These pads are typically 10 cm thick and can store more water, which increases the unit’s efficiency. Dadman Tahvieh’s cellulose pads are made from craft paper, are resistant to decay and contamination, and are washable. They have a high capacity for absorbing and retaining water.
Other Features
Centrifugal Fan: This is the primary part of the cooling system. With its high-speed rotation, the fan draws in a massive volume of air. The fan is responsible for the most important function of the centrifugal cooler: generating airflow.
Powerful Motor: The cooler is equipped with a high-speed Electrogen motor. The motor’s power ranges from 1.5 to 15 horsepower, depending on the cooler’s airflow capacity. For the 75,000 capacity model, the motor power is 15 horsepower with a speed of 1400 RPM. The motor is responsible for turning the fan and is crucial for the unit’s stability and overall efficiency. The fan and motor are connected by a pulley system, with the pulley possibly made of aluminum with a cast iron core.
Water Transfer System: Dadman Tahvieh centrifugal coolers include one to two water pumps, which can be a standard cooler pump or a submersible pump. For the 75,000 capacity model, one submersible pump is used. The water transfer system’s job is to supply water to the pads, and the quality of the pump significantly impacts the cooler’s overall performance.
Equipped with Vibration and Motion Dampeners: Given the high-performance operation of the centrifugal cooler and the potential for vibration, these dampeners are installed to prevent excessive movement and noise.
Static and Dynamic Balancing
High-Quality, Greased Bearings
Inverter Installation Capability for Motor Speed Control: This optional feature helps optimize energy consumption and regulate the airflow of the centrifugal cooler.
How a Centrifugal Cooler Works (Evaporative Cooling)
The basic principle of a centrifugal cooler is based on evaporative cooling. The process works as follows:
- Air Intake: The powerful centrifugal fan draws a large volume of warm, dry outdoor air into the unit.
- Passing Through Moist Pads: The absorbed air then passes through the cooling pads (cellulose pads). These pads are continuously kept moist by the centrifugal cooler’s water transfer system.
- Water Evaporation: When the warm air comes into contact with the moist surface of the pads, the water evaporates. This process absorbs heat from the air, which lowers its temperature.
- Distribution of Cooled Air: The cooled air is then blown and distributed into the desired space at a suitable pressure by the centrifugal cooler’s
This process is most efficient in areas with low humidity.
Main Components of an Industrial Centrifugal Cooler
A centrifugal cooler consists of several main parts:
- Cooler Body: The housing that protects the internal components, typically made of galvanized sheet metal.
- Centrifugal Fan: The main impeller that draws air in and blows it out.
- Cooler Motor: Provides the necessary power for the fan to rotate.
- Water Transfer System: Includes a pump and sprayers that deliver water from the cooler’s reservoir to the cooling pads.
- Water Reservoir: Stores the water needed to keep the pads moist.
- Cooling Pads: The evaporative surface of the cooler where air passes through to be cooled.
Types of Centrifugal Fans in Coolers
The centrifugal fan is one of the most vital components of these coolers. In a centrifugal fan, the direction of airflow is perpendicular to the impeller’s axis; air enters parallel to the axis and exits radially. Centrifugal fans are capable of creating relatively high pressure. Based on the impeller shape and the way air rotates within the centrifugal cooler, centrifugal fans are divided into four main categories:
Forward-Curved Centrifugal Fan
- Has blades that curve in the direction of rotation.
- The impeller has numerous, shallow blades.
- Air exits tangentially.
- Considered one of the quietest fans.
- Its main drawback is low efficiency, and it should not have a high motor speed.
Backward-Curved Centrifugal Fan
- Often operates with high motor power.
- Suitable for centrifugal coolers with long ducting runs and high pressure drops.
- Has higher efficiency.
- Can be used in places with high humidity and temperature or spaces with a lot of suspended particles.
- Potential drawbacks are dust absorption and noisy operation due to high motor speed.
Airfoil Centrifugal Fan
- Has airfoil-shaped blades that are highly efficient.
- Has low rotational mass.
- Can achieve an efficiency of over 85% in a centrifugal cooler, which is the highest efficiency among all fan types.
- Produces the least amount of noise among other centrifugal fans.
- Used for high flow rates.
- Its blades are susceptible to erosion.
Radial Centrifugal Fan
- The blades are placed directly on the scroll housing.
- They have the lowest sensitivity to solid particles and dust.
- Their efficiency in a centrifugal cooler is the lowest, but they are used for conveying materials and contaminated air.
- High noise production is one of its drawbacks.
Cellulose Pads vs. Aspen Pads
The centrifugal cooler typically uses cellulose pads instead of aspen pads (wood wool). These pads are a thin layer of cellulose (the main material of craft paper) that have high resistance to decay and contamination and are washable. They have a very high capacity for absorbing and retaining water, keeping the pad surface constantly moist. Using cellulose pads in a centrifugal cooler increases cooling efficiency. They offer many advantages:
- Preventing the entry of microbes into the space.
- Less sediment buildup due to their self-cleaning property.
- Uniform cooling.
- Longer replacement intervals compared to aspen pads.
However, cellulose pads also have some disadvantages:
- They are more expensive, though this is compensated for in the long run due to their less frequent need for replacement.
- They may have an unpleasant odor initially.
- Their availability and spare parts are less common than for aspen pads. However, Dadman Tahvieh has completely resolved this issue by producing and widely distributing cellulose pads throughout the country.
In contrast, aspen pads are made from small wood shavings and are more economical. They have good efficiency in dry and very hot regions but do not match the efficiency of cellulose pads. The advantages of aspen pads include a lower price and low maintenance costs.
Their disadvantages include some parts of the pad remaining dry, which reduces efficiency compared to the cellulose pads of a centrifugal cooler, as well as asymmetrical water circulation, the need for more frequent replacement, and the potential to cause allergies.
Cellulose Pad Maintenance
Cooling pads should be replaced after a certain period, as failing to do so in a timely manner reduces the cooler’s efficiency. Although the centrifugal cooler’s cellulose pads generally need less frequent replacement than aspen pads, the replacement frequency depends on the pad’s quality and type. Honeycomb cellulose pads are suitable for both humid, coastal climates and hot, dry regions.
Applications and Suitable Locations for Centrifugal Coolers
Due to their high power and efficiency, industrial centrifugal coolers are ideal for cooling a wide range of large and industrial spaces. The applications for these coolers include:
- Factories and production workshops (for cooling production lines, assembly halls, and preventing equipment from overheating)
- Sports halls and stadiums (for creating a comfortable temperature for athletes and spectators)
- Industrial warehouses
- Hospitals (for a comfortable and hygienic environment, preventing bacterial growth, and reducing the risk of infection)
- Large industrial, residential, and commercial complexes (including shopping centers, hotels, restaurants, etc.)
- Villas
- Warehouses
- Data Centers (to prevent equipment failure due to excessive heat)
- Greenhouses, poultry, and cattle farms (for regulating the temperature and humidity essential for plant growth or the health of livestock/poultry)
- Mosques and Hosseiniyyehs
- Schools
- Carpet cleaning facilities
- Government organizations
Advantages of Using an Industrial Centrifugal Cooler
Using a centrifugal cooler offers significant advantages:
- Very high cooling power: They can cool and distribute a large volume of air at high speed and pressure.
- Very high efficiency.
- High energy efficiency and low energy consumption: Due to its optimal design, the centrifugal cooler has high energy efficiency with low and optimized electricity and water consumption. Using these coolers can lead to cost reduction in the long run.
- Easy and low-cost maintenance and repairs: They have simple and durable parts and do not require complex and expensive repairs. The simple structure allows for maintenance without the need for special expertise.
Other Advantages
- Reduced Dust and Improved Air Quality: By cooling the air, they naturally reduce dust and airborne particles. Some models of centrifugal coolers are also equipped with filters to remove pollutants.
- Suitable for Hot and Dry Climates: They perform exceptionally well in this type of climate.
- Variety in Design and Capacity: They are produced and offered in a wide range of capacities.
- Low Noise Production: Their design allows them to produce less noise. However, noise production naturally varies based on the quality of the fan, motor speed, and the cooler’s capacity.
- Very High Resistance and Durability: Centrifugal coolers are designed to withstand harsh industrial conditions and can operate for years with minimal maintenance costs.
- Capability to Install a Timer and Remote Control System.
- Economic Benefits: Their purchase, installation, and running costs (electricity consumption) are significantly lower than systems like air conditioners.
Differences Between Centrifugal and Axial Coolers
When choosing a ventilation system for industrial environments, it’s important to compare the centrifugal cooler with the axial cooler. A centrifugal cooler has a higher airflow volume than an axial cooler. It also produces relatively less noise during operation. Most importantly, a centrifugal cooler can be installed in any space that has been ducted. The centrifugal fan works in a scroll-like manner, moving air in a circular motion.
Centrifugal Fan with Electric Motor
In contrast, industrial axial coolers use an axial system to move air and can be used in industrial and semi-industrial spaces without the need for ducting.
Types of Industrial Centrifugal Coolers by Capacity, Body, Installation, and Air Discharge
Centrifugal coolers are offered in various types:
- Airflow Capacity: They are produced in a wide and variable range of capacities. Common capacities include 11,000, 13,000, 15,000, 20,000, 30,000, 40,000, 50,000, and 75,000 (in cubic meters per hour or equivalent).
- Low Capacity (11,000 to 15,000 m³): These centrifugal coolers are suitable for small workshops, stores, offices, and administrative spaces.
- Medium Capacity (15,000 to 40,000 m³): Suitable for commercial halls, factories, and medium-sized organizations.
- High Capacity (above 40,000 m³): Suitable for factories, large sports halls, and public venues.
- Body Type: The body can be made of metal (such as galvanized or aluminum) or plastic. As mentioned earlier, the Dadman Tahvieh centrifugal cooler is made of galvanized steel.
- Installation Type: They are installed on a base, either on a wall, ceiling, or on the floor.
- Air Discharge Type: Centrifugal coolers are typically produced in three models:
- Top Discharge: It blows cool air upwards. Suitable for spaces with high ceilings and for uniform ventilation.
- Front Discharge: It directs cool air straight forward. Suitable for spaces with low ceilings and for directing air to a specific point.
- Bottom Discharge: The fan of this centrifugal cooler is located at the bottom of the unit and blows air downwards. It is usually installed on the roof or on strong platforms.
Guide to Selecting and Purchasing a Suitable Centrifugal Cooler
Selecting the right centrifugal cooler requires considering several parameters:
- Calculating Cooling Needs and Determining Appropriate Capacity:
- This is the most crucial step. The volume of the intended space must be calculated in cubic meters (Length × Width × Height).
- Next, based on the space’s usage type, the appropriate air change rate per minute is determined.
- The required capacity in CFM (Cubic Feet per Minute) is calculated by dividing the space volume by the air change rate.
- Finally, a centrifugal cooler with a standard capacity close to and larger than the calculated value should be chosen.
- Other factors such as the building’s floor plan, the number and size of vents, the length and type of ducting, the region’s temperature, and the cooler’s location (in direct sunlight or shade) also influence the final capacity determination.
- In regions with high temperature and humidity, standard evaporative coolers may no longer be sufficient, and other systems like air conditioners might be necessary.
- Type and Model of Cooler:
- The appropriate centrifugal cooler should be selected based on the environment’s application (factory, hospital, warehouse, etc.) and its specific conditions.
Other Important Points
- Climate Conditions: In areas with specific climate conditions, the choice of cellulose pad type (regular or anti-sediment) is important.
- Noise Level: If the environment is sensitive to noise, pay attention to the sound level produced by the centrifugal cooler.
- Energy Consumption: Check the energy consumption based on the cooler’s capacity and power. However, Dadman Tahvieh’s coolers are generally low-consumption.
- Component Quality and Manufacturer Brand: Using quality components in manufacturing saves energy and increases the cooler’s lifespan. Choosing a reputable company or brand with proper after-sales service is of high importance. Dadman Tahvieh guarantees the quality of its components with an 18-month warranty and 15 years of after-sales service.
- Price: The cooler’s price should be appropriate based on its capacity, type, energy consumption, and other features. The price varies due to the variety of models.
Important Points for Installing an Industrial Centrifugal Cooler
Proper installation of a centrifugal cooler is essential for optimal performance and a long device lifespan:
- Installation Location: It should be installed in a well-ventilated area, away from sources of heat and dust.
- Level Surface: The surface beneath the cooler must be completely flat and level to prevent vibration and excess noise.
- Foundation: For high-capacity centrifugal coolers, a proper foundation is necessary.
- Ducting: The air ducts must be properly installed and insulated to prevent the loss of cool air.
- Electrical Connections: This must be done by a professional electrician and with adherence to safety precautions.
Maintenance, Repair, and Lifespan Extension of a Centrifugal Cooler
Proper and regular maintenance is important for preserving the efficiency and extending the lifespan of an industrial centrifugal cooler:
- Periodic Service and Maintenance: The cooler should be periodically serviced and maintained by specialists. Annual service by a professional technician is recommended.
- Regular Cleaning: Regularly clean the cooling pads, fan, filters, and cooler body from dust and dirt. Cellulose pads can be easily cleaned.
- Check Water Level: Regularly check the water level in the centrifugal cooler’s reservoir and add filtered water if needed.
- Check Belts and Bearings: Check the belts for wear and tear and the bearings for lubrication and condition. Replace or lubricate as needed.
- Inspect the Electric Motor: Inspect the motor for overheating, vibration, and unusual noises.
- Replace Cooling Pads: Pads should be replaced after a certain period to prevent the efficiency of the centrifugal cooler from decreasing.
- Use in Suitable Conditions: Use the cooler in an environment away from dust, humidity, and corrosive chemicals.
- Avoid Constant On/Off Cycling: This puts stress on the cooler.
- Use Original Spare Parts: If a replacement is needed, use original and high-quality parts.
If any problems occur, troubleshooting and repairs must be performed by experts.
Conclusion
The centrifugal cooler, as a powerful and efficient cooling system, is considered an ideal option for cooling large industrial, commercial, and sports spaces. Features such as high efficiency, high-pressure distribution capability through ducting, high energy efficiency, high durability and resistance, and low maintenance costs make them very cost-effective.
By correctly choosing the capacity, type, and a reputable brand, as well as observing installation and maintenance tips, you can benefit from the cool and comfortable air provided by these coolers for years to come. For more information and consultation on selecting a suitable cooler, you can contact Dadman Tahvieh’s experts to purchase a centrifugal cooler.
