Ventilation reversible inline duct fan

Types of Reversible Inline Duct Fans

A ventilation reversible inline duct fan is a fan that can change the airflow direction by reversing itself. Such a function is facilitated by a motor controller that allows the fan to exhaust or intake air by reversing the direction of rotation. Generally, ventilation reversible inline duct fans are designed for flexible ventilation in different applications like rooms, classrooms, and greenhouses, to mention but a few. Below is a breakdown of the common types:

• Electric Reversible Inline Duct Fans:

A duct fan motor can be controlled through an electric switch for bidirectional air movement. This simple control is commonly seen in small duct fans where the speed or function is simply changed by switching on or off the electric switch. It can also be seen in larger fans where simple speed control or reverse control is done through a VFD (Variable Frequency Drive). The advantage of this simple control is the simplicity of the installation. It is a straightforward way to give the end user the ability to reverse the direction of the airflow.

• Pressure Activated Reversible Inline Duct Fan:

  This fan works automatically based on pressure difference in ducting. In a scenario where there's a constant flow of air through a system like a furnace or an air conditioning system, the pressure changes direction creating a change in the polarity, which then activates the fan to reverse direction. This is great because the fan doesn't need any manual control. The downside is that the activation of the fan is dependent on the pressure change. There might be delay or lags in the fan picking up the change and reversing.

• Temperature Controller Reversible Inline Duct Fan:

A reversible inline duct fan can be controlled through temperature. In case there's a need to exhaust hot air from a room or to intake cold air to a room, a temperature switch can be used in conjunction with the fan. When the preset temperature is achieved, the fan will reverse. This is commonly seen in greenhouses or in industrial setting where certain room temperature is set to achieve a specific reaction or to maintain a certain temperature within a premise. The advantage with this is that the fan can be used to condition a room set to achieve a certain temperature. The downside is that it can be over or under shooting the requirement. There might be delay in the temperature change to fan reversal.

Specification and maintenance of ventilation reversible inline duct fans

Specifications

• Material: The casing material of a duct fan is usually engineering plastic or stainless steel. Engineering plastic is lightweight, and the duct fan will corrosion. Stainless steel has strong strength, and it is also resistant to corrosion. Both materials can be used for a long time.
• Noise: Inline duct fans tend to make less noise compared to other exhaust fans. The noise level of duct fans are usually 20 to 40 decibels, which is close to the sounds of rustling leaves. Some smaller models may even produce a sound less than 20 decibels.
• Airflow: Duct fans are measured in CFM. A 4-inch duct fan moves about 40 CFM of air, while a 10-inch duct fan moves about 370 CFM. The greater the size of the fan, the higher CFM it would generate.
• Speed: Duct fans generally operate at speeds of 1,200 to 3,000 revolutions per minute (RPM). Some models of the fan may allow users to change its speed.

Maintenance tips

• Consider cleaning the duct fan at least twice a year. Make a schedule where the user can clean the duct fan and stick to it.
• While the duct blower is running, the user can spritz some water into the duct to moisten and clean it.
• When cleaning the external part of the duct fan, use a dry/microfiber cloth to wipe and remove any dust settled on the surface.
• Use a vacuum cleaner with a soft brush attachment to clean the fan blades. Gently run the brush over the blades to remove dust and dirt.
• For inline duct booster fans, avoid putting any equipment or object on top of them to prevent blockages.

Uses of a reversible inline duct fan

Wholesalers, retailers, and other commercial and industrial end-user buyers constantly seek effective and reliable ventilation solutions. The reversible inline duct fan provides this by serving different industries and spaces.

Indoor spaces such as basements and bathrooms tend to have a high humidity level. This can encourage the growth of fungi such as molds, which can damage property. A ventilation reversible inline duct fan can be used to exhaust moist air out of the room to keep it dry and reduce the humidity level. If the humidity tends to be low, the fan can be used to bring in moist air into the room. Temperature fluctuation can also be experienced in rooms with heating or cooling systems like furnaces, boilers, and duct AC. Using a reversible duct fan can help maintain the desired temperature by circulating air to different parts of the room.

People living or working in areas exposed to irritants such as dust, smoke, toxic fumes, and odors can use a reversible inline duct fan to ventilate the area. The fan can be set to exhaust the irritants out to improve the quality of air within the room. Industrial facilities such as factories that use chemical substances also have a high possibility of having hazards like toxic fumes. A duct fan can be used to mitigate such hazards by exhausting the toxic fumes to improve air quality.

A reversible inline duct fan is designed to be very quiet. It can be installed in places that require a noise level to be low, such as libraries, schools, and offices, to improve air circulation. In animal houses such as poultry farms, duct fans can be used to provide the right temperature and air exchange for the birds to promote their health. Fungi, bacteria, and vermin in warehouse storage facilities can easily damage goods like food products, furniture, and clothes. Using a duct fan can keep such warehouses dry by exhausting moist air, thus helping to preserve the goods.

Commercial buildings such as offices and hotels can use a duct fan to provide fresh air to rooms that have been closed for some time. Restaurants and cafeterias can benefit from an inline duct fan by reducing cooking odors so patrons can enjoy their dining experience. The versatility, efficiency, and effectiveness of a reversible inline duct fan make it a suitable ventilation solution in different industries and application areas.

How to choose a reversible inline duct fan

Here are some major factors to consider when buying inline duct fans:

• Airflow and pressure

  The airflow capacity is the primary factor to consider when purchasing an inline duct fan. Airflow is measured in cubic feet per minute (CFM) and represents the volume of air the fan can move. It is also important to consider the fan's static pressure for the intended application. Static pressure is the resistance force the fan overcomes to move air through a duct system. Operating fans with the correct airflow and static pressure ensures efficient operation and system performance.

• Fan speed and controls

  Inline duct are offered in different speeds to handle various applications. Typical fan speeds are low, high, and single-speed options. High-speed is suitable for high-volume applications, while the lower speed is adequate for smaller spaces. Some fans operate at a fixed speed, while others allow the user to adjust the speed to meet changing ventilation needs. Fans with speed control options give users the ability to manage noise, airflow, and energy consumption.

• Airflow direction

  Consider whether the fan's air movement is toward or away from the source of pollution. For effective removal of pollutants, it is recommended to position the inline fan as close as possible to the source of pollution. If the source of pollution is farther away, consider using a duct fan with air-reversing capability. This option allows for flexible air ducting routes depending on the unique application needs.

• Fan housing and mount

  A duct fan housing provides protection from environmental elements such as dust and water. The housing is usually made from galvanized steel or PVC. Different housing shapes, such as circular or rectangular, are available to fit various duct sizes. The duct fan can be permanently fixed to the duct system using clips and brackets or detached from the mount and moved to another location.

• Noise level

  Inline fans operate at different noise levels depending on their type and design. Noise is measured in decibels (dB) and is indicated on the specification sheet. Choosing the right inline duct fan for an application helps to minimize noise pollution in the environment. Consider installing a silencer or selecting a fan with a quieter rating for areas that are sensitive to noise.

• Power consumption

  Inline duct fans use power, which is expressed in watts. The power consumption of a fan is further impacted by its airflow, speed, efficiency, and run time. Selecting a fan with the appropriate CFM and static pressure for the application helps to lower power consumption. Users can also implement speed control to reduce energy usage.

Q&A

Q1: What is the difference between a ducted and ductless fan?

A1: A ducted fan, like the inline duct fan, works with a ventilation system that channels air through pipes. It boosts the airflow within that enclosed piping system. Conversely, a ductless fan doesn't have that standardized setup. Ductless fans typically offer more flexibility and less equipment cost.

Q2: What materials are commonly used in the construction of duct fans?

A2: Duct fans' outer housing or ducting is commonly made of PVC, aluminum, aluminum alloy, galvanized steel, or stainless steel, which is sturdy, corrosion-resistant, and has a long lifespan. The blade and impeller material choices are similar to the housing, with the addition of engineering plastic. The motor components of a duct fan, particularly the stator and rotor, are primarily metallic, typically iron (with copper windings) and alloy materials. The selection of materials for a duct fan not only affects its performance but also its durability, noise level, and energy efficiency.

Q3: What are the airflow ratings for duct fans?

A3: Duct fan airflow is measured in cubic feet per minute (CFM). Different fans have different CFM ratings, which indicates the amount of air the fan moves per minute. Generally, the higher the CFM, the more air the fan will move. However, CFM ratings can vary from model to model and manufacturers.

Q4: Can a duct fan be used for residential spaces?

A4: Yes, many inline duct fans are used in the home. Common uses are in crawl spaces, attics, and garages, as well as for kitchen ventilation. It's essential to choose a fan that's designed for household use, as industrial and commercial models may be too noisy or powerful.