In many systems and devices, heat buildup can lead to increased safety risks, reduced performances, and prematurely deteriorated components. Due to these reasons, many pieces of equipment utilize cooling fans. These will help to dispel the heat buildup. It will also help to avoid potential consequences that could be costly.
Cooling fans are used in a variety of products. They come in different configurations and designs to fit different application restrictions and requirements. The wide variety will make it possible for engineers and product designers to find the component that will meet their needs exactly. While it can help them find the right component, it can also be challenging at times to find the right one.
This guide will help make the selection easier. It is going to outline the steps you should follow when you are choosing a cooling fan for a certain application.
Selection Process for Selecting a Cooling Fan
Step 1: Do a Thermal Analysis
This is the first thing you should do when selecting a cooling fan. This type of analysis will determine the amount of heat that is generated inside a certain piece of equipment. It will also determine the amount of heat during a certain process. Once you have the result, you can use it to calculate what volume of air that will be needed to cool the system or device.
This analysis uses instruments such as sensors to determine the source(s) of heat. It will also determine how much heat is generated by each of the sources. The components that are the heaviest consumers of power are often processors, MOSFETSs, microcontrollers, and FPGAs. In heat dissipation, these are often the biggest contributors. After you get the necessary information, you can calculate how much airflow is going to be required to cool the system or device. Next, you can map the cooling air path using software and sensors. They will help to ensure that all the major sources of heat will receive the air that is needed to sufficiently cool them.
Step 2: Finding out the System Impedance
After you have calculated the air volume, you will need to determine the system impedance. This is the sum of the drop in pressure. It is experienced as the air travels between the fan’s exhaust vents and inlet vents. When a system has many different air pats, you will add the individual impedance values. You can measure the value(s) for different airflow rates. You can do this by putting the system in an air chamber or using pressure sensors.
Step 3: What Type of fan do you Choose
Once you have identified the system impedance, you can use it to calculate the airflow that is required to gauge the static pressure that is needed for the system. You can use this information to determine which fan you will need and be the best solution for your issue.
There are two categories of cooling fans, which are based on the way that the air will flow through them.
- Centrifugal fans: This type of will have the air enter in one plane and then exit in another plane. These planes have rotating impellers. The impellers have blades, which will increase the speed of the air streams. It will then convert it into pressure. This fan is suitable for applications that involve harsh conditions such as dirty or moist air streams. These fans can also produce high pressures.
- Axial fans: This type of fan will have the air enter and leave in the same plane. The impellers, which are like airplane propellers, have blades that pressurize the air. They also generate aerodynamic lift. This fan is ideal for any applications that involve static pressure that is relatively low. This fan can also provide high airflow.
When trying to decide which fan design you need, here are some factors to consider.
- Airflow rate
- Operating environment and temperature range
- Rate of efficiency
- Delivery time
- Noise generation
- Space constraints
- Drive configuration
- Static Pressure
Step 4: Last Considerations
There are other considerations you need to think about in addition to the above three steps before choosing which cooling fan you need for your system. They include:
- Maintenance programs/schedules: No matter which cooling fan you select; you have to establish a maintenance plan. You will first have to create and then implement a schedule for it. If you do not, the unit could unexpectedly break down. If you use a maintenance program, it will cover the following items: leakage, bearings, system cleaning, sheaves and belts, and motor condition.
- Integrating the speed controls:If the fan is going to run at fast speeds continually will quickly burn out. When you use the Integrating speed control element, you can alter the fan’s speed when it is needed. This will help to increase the service life of a unit overall.
- Monitoring circuits: Integrating performance monitoring circuits can track the performance of the fan. By doing this, it will help to find potential malfunctions before they happen.