When it comes to protecting sensitive electronic equipment housed within enclosures, maintaining an optimal operating temperature is crucial. Enclosure filter fans are an essential component of thermal management systems, designed to expel hot air and draw in cooler ambient air. We’ll guide you through the process of selecting an enclosure filter fan to ensure the reliability and longevity of your electronics.
1. Consider the Environment
Factors such as ambient temperature, humidity levels, solar radiation, and the presence of dust or contaminants will influence fan selection. It is recommended that the filter fan’s IP or NEMA rating meets or exceeds those of the enclosure. In wash down scenarios or when encountering snowy conditions, some manufacturers offer rain hoods, which provide an additional layer of protection against water infiltration and snow accumulation.
2. Assess Heat Load
Begin by calculating the heat load generated by the electronics inside the enclosure. This involves identifying the total wattage of components, including power supplies, drives, PLCs, relays, and any other heat-producing devices. Reference the manufacturers’ technical specifications which can be found either in their data sheets or manuals.
3. Determine Required Airflow
Based on the heat load, you can calculate the required airflow rate (measured in cubic feet per minute, CFM) using an enclosure cooling calculator. As a rule of thumb, each filter can reduce the airflow by about one third. Therefore, when selecting the fan size, the free flow CFM should be three times the required air flow rate calculated to provide sufficient cooling.
4. Enclosure Size and Material
In general the larger the surface area of the enclosure, the better it can disperse the heat. Also, certain types of enclosure materials will dissipate heat more effectively than others. Painted steel and non-metallic enclosures radiate heat better than stainless steel or unfinished aluminum.
5. Fan Size and Voltage
Select a fan size that fits the available space in the enclosure while providing the required airflow. Ensure the fan operates at the appropriate voltage to match your AC or DC power supply.
6. Noise Level
Consider the noise level produced by the filter fan, especially if the equipment is located in a noise-sensitive environment. Manufacturers typically provide noise level information in decibels (dBA) or offer low-noise versions of their fans. Some fans are designed to operate quietly, while others may be noisier but offer higher airflow.
7. Installation and Maintenance
Choose a fan that allows straightforward mounting and easy filter replacement. It is recommended to install the filter fan near the bottom of the electrical cabinet since cooler ambient air is more dense. On the other hand, place the exhaust filter near the top since warm air rises.
Final Considerations
The “rule of thumb” is that for every 18°F (10°C) over the rated temperature limit, the life expectancy of the electronic components gets cut by 50%. That being said, best practice would be to keep control cabinets internal temperature at or below 95°F (35°C). We recommend adding a normally open (NO) thermostat to the system. This device activates the fan when the enclosure temperature exceeds a set threshold, ensuring energy efficiency.
Filter fans are a good choice when the environment is free of containments or gases and ambient temperature is lower than the desired temperature within the enclosure. If that is not the case, a closed-loop system like an air conditioner is recommended.
Selecting the right filter fan will pay off in improved equipment reliability and reduced downtime. By calculating heat loads, considering the environment, and choosing the appropriate fan size/CFM, you can ensure effective temperature control and extend the life span of your electronics. Proper installation and regular maintenance are equally crucial to the fan system's performance.
If you have any questions on what enclosure filter fan is best suited for your application give us a call at (888) 886-8185 or send us an email.