Fans for Enclosures & Electronic Systems – Sourcing Guide

What gets bigger as electronic devices get smaller and denser?

Your heat problem.

Today, electronics-dependent markets are demanding more power in an ever-shrinking package. From AI to datacom, automation, energy, and transportation, this is creating a tricky thermal and atmospheric environment for products and operations. In other words, most critical units these days create a ton of heat and need fans that can prevent damage, failures, and shutdowns.

Sourcing an enclosure fan isn’t as simple as knowing your assembly’s cubic-feet-per-minute requirements. It’s time to learn all the factors that determine whether a mini fan can keep your device cool, calm and collected under thermal stress.

7 Factors in Enclosure Fan Sourcing 

It's a given that you want components that are low-cost and quick to arrive at the loading dock. But being cost- and time-efficient for the long term are about more than the initial purchase point.

Carefully consider your electronic fan needs in:

1. Airflow
2. Type of air movement
3. Space
4. Power requirements
5. NEMA rating
6. Noise
7. Installation & maintenance
   
   

1. Airflow

Airflow rating indicates the volume of air a fan can move in a certain amount of time. Wind and air volume are not synonymous. You can have a light breeze, but move a large volume (depending on the fan design). 

The standard measurement is cubic feet of air per minute (CFM). Fan manufacturers usually specify airflow for a given static pressure (i.e. the atmospheric pressure in the enclosure when there’s no air moving).

Airflow rating has a huge impact on what will and won’t work in your assembly.

To specify the right airflow, you’ll need to know the enclosure’s required internal temperature. The further you can keep the temperature below that upper limit, the better.

Thermal load is the other half of the heat-management puzzle. (There's a calculation for this.) An assembly’s thermal load includes the total wattage of:

• Power supplies
• Relays
• PLCs
• Any other parts that create heat

This will give you a better idea of how strong or big a fan you’ll need – to a point. There are two places buyers sometimes trip up when choosing enclosure fans:

• A bigger fan doesn’t necessarily mean more airflow
• CFM rating is different from power rating (more on that in a bit)

One easy practical solution? Over-specify the fan. If the engineer intends for the fan to operate at 75 CFM, consider a fan that offers a max of 100 CRM. This leaves some margin for error and the option to increase airflow later.

2. Type of Air Movement

Unlike the ceiling fan in your living room, industrial fans are sometimes more about air management and distribution than cooling.

Furthermore, not all industrial component fans work the same way. Before selecting a component fan, get a handle on the type of air movement you need.

The two types you’re probably most familiar with are axial fans and centrifugal fans (a category that includes blowers). Overall, axial fans are lighter, simpler designs that are easier to install. Centrifugal blades are generally a more advanced and efficient solution (up to 90% efficiency, vs. 85% for axial).

These are just two of many fan solutions for cooling electronics. Your market or application might benefit from a more specialized approach:

• Tubeaxial Fans – power supplies, telecommunications, industrial controls, storage devices, medical equipment, workstations, cabinet ventilation, air filtration
• Motorized Impellers – telecommunications equipment, disk drives, mini-computers, HVAC, testing & instrumentation, roof ventilators, convection ovens & range hoods
• Flatpaks – spot cooling, medical equipment, telecommunications
• Crossflow Blowers – food processing equipment, refrigeration, industrial dryers
  
  

3. Space

Electronic component selection is often an exercise in balancing performance with size.

Fans range from the size of your hand to the size of a door. In most enclosed applications, though, smaller is usually better from an efficiency standpoint.

Only buy cooling components that will easily fit inside the electrical cabinet. There should also be enough CRM for the duct pipe’s or hose’s size. 

Futureproofing is a smart way to manage not only space, but also the cost of modifications. If there’s a chance the system will expand in functionality someday, make sure the fan’s size won’t be a physical obstacle to that happening. Size goes both ways – it might be worth using a slightly larger fan if future upgrades might increase the system’s cooling needs.

4. Power Requirements

The power consumption of a fan directly influences the operational cost. Pricey or not, you’ll have to meet the project’s voltage and current requirements.

The primary specs to know are:

• Voltage compatibility: Fans need to operate at specific voltages (i.e. 12V, 24V, 48V). Ensuring that the fan’s voltage matches the available power supply will prevent electrical mismatches that can lead to inefficiency or equipment damage.
  
  
• Current draw: The amount of AC power a fan demands will impact the overall system’s energy efficiency. Higher current draw indicates higher power use.

Sourcing a fan that hums along efficiently under the application’s load conditions can lead to cost savings over time, especially in systems that run continuously. At the same time, energy-efficient fans produce less heat, which can extend the lifespan of the system.

5. NEMA Rating

Just because a fan can control temperature and air quality doesn’t mean it’s impervious to the world around it.

The working environment is still an important factor in your purchase, especially if the fan will be outside. The application may call for electronic equipment fans that are rainproof, dustproof, or some other -proof.

Select a fan with an appropriate NEMA rating. Simply put, an appropriate NEMA rating is one that meets or exceeds the enclosure’s own NEMA rating.

There are many categories in the NEMA standards system. The ratings most relevant to industrial fans are:

IP ratings are also relevant to component fan selection. IP-rated fans are available to guarantee protection against water and solid particle ingress.

6. Noise

Will people be present around the fan during operating hours? How important will it be for those people to communicate with each other and hear their environmental surroundings?

Fans with lower decibel ratings can make the workplace safer and more comfortable.

Smaller fans tend to operate at higher RPMs to achieve the same airflow as a larger fan. Often, smaller actually equals noisier. 

Axial fans are normally quieter than centrifugal fans and blower-type fans.

7. Installation & Maintenance

The maintenance team will thank you if your fan choice allows straightforward installation and future access. 

It starts with the mounting process. Different installation styles offer differing degrees of difficulty (sometimes depending on the environment).

In short: Choose a fan that matches the installation environment. Note that axial fans are usually easier to install than their centrifugal counterparts.

Of course, a fan’s design should also allow for easy access to filters or other replaceable components. Fans in cramped spaces might be harder to service or replace – this goes back to sizing the component properly for its working space.

From Enclosure Fans to Every Other Electronic Component

Picking the right internal component fan for your industrial-grade job involves careful consideration of:

• Blowing strength and type
• Power requirements
• Working conditions

By understanding the different types of fans available and assessing their features vs. your specific needs, you can optimize your product or operation’s cooling performance. That means a longer-lasting device, and that’s always cool.

Sourcing other electronic parts involves asking some of the same questions you would for fans, while some criteria are 100% unique to that part type. To make sure you’re sourcing all components cost-effectively and wisely, grab our free guide: