Optimal Fan Placement in a PC Case (Best Airflow Setup)

Fan placement can make or break your cooling performance. Even with high-end hardware, poor airflow leads to higher temperatures, louder fans, and thermal throttling.

This guide breaks down exactly where to place your case fans — including side-mounted fans — for optimal airflow and lower temps.

Intake vs Exhaust (The Basics)

Intake fans pull cool air into the case. Exhaust fans push hot air out.

• Cool air should enter from the front, side, or bottom
• Hot air should exit from the top and rear

Front Fans (Primary Intake)

Front-mounted fans are the main source of fresh air for your entire system.

• Direction: Intake
• Feeds CPU, GPU, and motherboard
• Usually filtered for dust

Side-Mounted Fans (Critical for GPU Cooling)

Side-mounted fans are often misunderstood — but when used correctly, they are one of the most effective cooling upgrades.

• Recommended Direction: Intake
• Direct fresh air straight to the GPU
• Ideal for high-end or vertically mounted GPUs

Rare exception: Side exhaust may work only if front airflow is blocked — otherwise avoid it.

Bottom Fans (If Your Case Supports Them)

• Direction: Intake
• Feeds GPU directly
• Requires dust filters and floor clearance

Top Fans (Always Exhaust)

Heat naturally rises — top fans should always push air out.

• Direction: Exhaust
• Perfect location for radiators

Rear Fan (Final Exhaust Point)

• Direction: Exhaust
• Removes leftover CPU heat
• Small fan — big impact

Positive vs Negative Air Pressure

• Positive Pressure (Recommended): More intake than exhaust, less dust
• Negative Pressure: More exhaust than intake, pulls dust through gaps

Common Fan Placement Mistakes

• Side fans set to exhaust
• Top fans configured as intake
• Random fan directions
• Too many fans with no airflow path

How Many Fans Do You Really Need?

• 3–4 fans: Minimum
• 5–7 fans: Ideal for most builds
• More fans ≠ better temps if airflow is wrong