A simple rule of thumb: If the cabinet temperature consistently exceeds the recommended operating temperature of its most sensitive electronic components (typically 35-40°C) or is significantly higher than the ambient temperature outside the cabinet, you need to implement active cooling. Persistent overheating can cut the lifespan of electronic components in half or more, making fan installation the most cost-effective safeguard.

The placement of any enclosure cooling system is best implemented based on the principle of thermal convection; cold air in the bottom and hot air out of the top.

Positive Pressure (Pressurizing): It is the favored and optimal technique. A fan and filter unit (an electrical cooling unit) is placed in the lower section of the enclosure to force cool filtered air into the casing, and an exhaust grille is in the upper section. This arrangement produces a clean, pressurized fan cooled enclosure that is essentially a barrier to the passage of dust and contaminants into the cabinet via unsealed openings.

Negative Pressure (Exhausting): The other is negative Pressure, in which a fan on the top of the building removes hot air. This is effective in removing heat, but this causes a vacuum effect that may cause dust and debris to enter the cabinet via any uncovered opening and damage internal parts.

One of the important elements in an efficient enclosure ventilation design is the ability to align the performance of the fan with the cooling needs. In case a single fan is not enough, the initial action will be to take into consideration a bigger, stronger model in case space is not a problem (such as ACDCFAN provides fans up to 280mm in diameter and up to 1150 CFM airflow). In case of inadequate space, you can design a multiple-fan array:

–Fans in Parallel: Two or more enclosure ventilation fans are placed side-by-side, pushing air in the same direction.

Effect: This doubles the total airflow (CFM), and the static pressure is almost the same as that with one fan.

Use Case: Ideal for enclosures with low system impedance (unobstructed airflow). Use this method when your goal is to move the largest possible volume of air for general heat exchange.

–Fans in Series: Two fans are stacked one in front of the other.

Effect: The total static pressure is approximately doubled, but the airflow (CFM) remains nearly the same as a single fan.

Use Case: Ideal for equipment with very high system impedance, such as densely packed components or long, complex ducting. Use this method when you need powerful pressure to “push” air through these obstructions. ACDCFAN’s radial fans (GRA and GRD series) and XPressure axial fans are specifically designed to overcome this type of high system resistance.