Recognizing the 3 Most Popular HVAC Fan Types in the Industry


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HVAC fans are considered as the workhorses of a ventilation system as it plays a very crucial role. Any ventilation systems will never be effective without the installation of fans. To put it simply, fans are utilized to establish consistent airflow, especially when necessary. In other words, it doesn’t occur naturally, but only when it is essential. This all makes sense why fans are considered a fundamental aspect of HVAC systems. When it comes to project management, a tool like a construction schedule software has also played a very critical role, and HVAC professionals couldn’t agree more.

In this blog, different types of fans are to be outlined alongside their major significance and distinctive characteristics. Take a closer look below.

1. Centrifugal Fan

This type of fan is usually categorized by their distinctive blade shapes – radial, backward inclined and forward-curved. It increases the air stream speed with the help of a rotating impeller. If you have noticed the fans in the home furnace or perhaps vacuum cleaners, it is one of a few ordinary centrifugal fans used presently. Centrifugal fans are capable of operating against an extremely high resistance, which makes it preferable to use for local exhaust type of ventilation systems. Additionally, a tool that is used for scheduling purposes is the best construction management software like Pro Crew Schedule. This one is the best and leading software tool favored by many project managers, contractors and subcontractors. It is often used for project management, scheduling and tracking purposes.

Moreover, probably the best type of centrifugal fans is the rugged radial blade, especially for exhausting massive amounts of dust. These fans are less likely to become more abraded or clogged by dust.


Four of the most common centrifugal fans are detailed below:

· Forward-Curved – these fans create more air pressure and it has hamster wheels. And because of the huge wheels, it tends to be noisier than usual compare to the axial fans and demands more power to run. Forward-curved types of centrifugal fans are believed to be very durable and are easy to maintain and clean. Hence, it doesn’t create any issues related to resistance.

· Airfoil – considered as the utmost efficiency type of fans that are best for clean air applications. And also, there are many technologies and software tools for construction scheduling purposes that continuously shape the way construction professionals handle projects, the crew and other involved aspects. Through using this, overall success for any construction projects is easily accomplished.


· Backward-Curved – its shaped blades are usually very uncommon that can look either straight or curved. However, because of its bizarre and unique shape, the fans are known to be excellent when it comes to higher and increasing volumes of airflow and variable resistance. It makes itself very useful for industrial purposes.


· Radial – known as the high-pressure fans having a very moderate or medium airflow. Fans that are radial bladed are proven to be best used for industrial applications wherein gas and dust are in the environment as well as extreme moisture in the air. HVAC professionals are obliged to use a project management software that undoubtedly helps them in handling and managing different projects alongside the crew members. The tool is comprised of realistic and innovative built-in functionalities that are designed to fill the needs of project managers and the overall team involved in the project.


2. Axial Fans


This type of fan functions like airplane propellers, which is obvious because three of its major components include propellers, vane axial styles and tube axial. With the comprised built-in parts, it is easier to move alongside the axis of fans and move on air streams. The propeller fans are usually used for cooling or perhaps dilution ventilation. The fans are going to be mounted in a separate ceiling or walls. An efficient and successful installation for the fans is best accomplished when project management for construction is implemented. HVAC professionals have major priorities and that includes project management.


 The three basic types of axial fans as being mentioned already have distinctive characteristics and it does include the below:


· Centrifugal fans are usually where local exhaust ventilation suited the most but not the axial or propellers fans. It is because it cannot provide enough suction when it comes to drawing air by the system.


· Can move an enormous amount of air if there’s a little resistance found


Vane axial and Tube axial fans are critical propeller fans purposely designed to fit inwardly in a duct. It is limited to clean air applications like exhaust ducts moving through the roofs. One of many main applications in HVAC systems when it comes to centrifugal fans is for air-handling units. This unit is required to blow air towards the ductwork consistently.


3. Backward Inclined Fans


The very first impression for this type of fan is that the attached blades do not appear like it was properly installed. Its unusual blade shapes usually characterize the fans. Moreover, this fan is made to handle significant volumes of generally clean air that has been totally required in HVAC systems. Apart from the systems itself, fans like this are also capable of handling exhaust applications and industrial air supply. Additionally, the drive mechanism of this might be a belt, direct or variable drive.


As being said earlier, this type of fan is commonly designed to be used for different industrial applications. These industrial applications have variable resistance and higher airflow like incineration systems, glass tempering, cooling process, etc. For commercial HVAC systems, these fans are typically utilized for energy-recovery ventilation.


Below are some of the most common features of backward inclined fans:


· Uninterrupted welded housings and efficient elimination of air leakage

· Two rotations available and having four discharge positions

· Availability for AMCA resistant construction: Types A, B and C

· The belt-driven model has included grease lubricated, heavy-duty and self-aligning optimal performance

· All fans have mechanical run test in order to be specific for proper alignment and balance

· Drive side plates and inlets are removable that allow blower wheel functionalities

· Heavyweight gauge steel basis having internal bracing that maximizes rigidity and longer the life equipment


Optimizing Fan Speed to Effectively Control Humidity


As buildings become more energy-efficient through the continuous increase in insulation levels, air tights have been enveloped. Thus, buildings and even homes are now facing new challenges in terms of cooling. The improved buildings and other sorts of properties have moderately caused the cooling loads to shrink over the past few years instantly. Finally, HVAC contractors have been forced to reconsider and rethink many times the sizing policies and methodologies of air conditioners and fans.


Fans typically remove two types of heat coming from the building:


· Sensible heat – picture out when measuring thermostats; it is where pure temperature rises.

· Latent heat – humidity or more like the gained heat related to the moisture from the air


Fans are capable of removing both sensible and latent heat, but then again, not equally. The average airflow can anytime be reduced if full airflow for fans isn’t much required. Overcoming it can be possible with intermittent operation. On the contrary, this particular approach isn’t viable for any applications, especially when consistent and controlled airflow is necessarily required. HVAC professionals know the fans are incapable of changing the speed and that only means a specific external device is much needed. This external device is for speed variation and yet other tools HVAC experts have been using include construction project management software. This software tool is mainly used for project management purposes.


Speed control is efficiently achieved either electronically or mechanically:


· For the belt-driven type of fans, it can be firmly equipped with pulleys of progressing diameter to gain several speeds available. This same effect and scenario can certainly be accomplished with gearboxes.


· Motors with multiple speeds are more practical when it comes to open discharge applications and axial fans.


· Variable Frequency Drives have conditioned both frequency and voltage that are supplied directly to the fans to accomplish speed modulation. An all-in-one transition between varieties of different rpm values is also allowed.


In these many different cases, the speed control will be directly related to the airflow. And yet, it will never be the same for ducted installations where it can be crucial to account for static pressure variations all because consistent airflow control can only be successfully attain with variable frequency drives.


Key Takeaways


In choosing among the different types of fans mentioned above, narrowing down your choices is crucial for you to determine the best option for your current and next HVAC projects. It has been a common knowledge already that both centrifugal and backward-inclined fans offer much superior performance in terms of applications and yet demand for additional costs.

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