When mounting the fans to the radiator of an AIO liquid cooler, they should fit tight against each other to maximize airflow. If a case has fan mounts inside the front panel, the flat metal frame will be between the fans and the radiator. Unless you have the Cougar MX330-G ATX case. The frame inside the front panel has raised vent holes and recessed screw holes. I used 20-year-old motherboard standoffs to mount the radiator to the back and the fans to the front of the frame. That ¼-inch gap between the fans and the radiator allows air to escape and blow back out the mesh front panel. It’s time to weatherstrip that gap!
Why Weatherstrip AIO Fans
A weatherstrip is a barrier between two surfaces that prevents air from escaping. Most common applications include doors and windows for cars, refrigerators, and homes. But not for computers. Since I have a 1/4-inch gap between the fans and the radiator, weatherstrip makes perfect sense.
I’ll be using Frost King Rubber Self-Stick Weatherseal Tape that is 5/16″ wide, 1/4″ tall and 17-feet long. This type is called a D-section with two parallel D-shaped tubes. The roll cost $6.50 USD on Amazon
Installing The Weatherstrip
Before installing the weatherstrip, I unscrewed the Phanteks Halo Lux RGB fan frames and the Be Quiet! Shadow Wings 2 fans. I cut the weatherstrip into four pieces that fit between a pair of standoffs and pulled apart each piece in half. I peeled off the backing and applied each piece, pressing down with my finger. The weatherstrip forms a square underneath each of the fans.
When reattaching the fans and frames, I start the first screw in one corner, the second screw in the opposite corner, and the remaining screws in the other corners. I then tightened down all the screws.
Testing Environment
I tested the system performance before and after applying the weatherstrip with Cinebench R23 for benchmarking and Ryzen Master for monitoring. I ran four multicore passes in Cinebench for each round of testing. The first pass was to warm up the liquid inside the closed loop and I discarded the initial score. The average of the next three passes represents the final score.
My editing system has an AMD Ryzen 7 2700 that boosted to 3.4GHz and the memory is overclocked to 3333MHz on the MSI Tomahawk X570 motherboard. Fan profiles were set to the “performance” profile in the BIOS. The processor temperature maxed out at 51C for each round of testing.
Test Results Before/After

Before I applied the weatherstrip to the fans, the Cinebench scores were 8,104, 8,076 and 8,035. The average score was 8,071. After I applied the weatherstrip to the fans, the Cinebench scores were, 8,181, 8158 and 8,148. The average score was 8,162. That is a 1% increase in performance.
I know what you’re thinking, “A 1% increase in performance, whoop dee doo!” When optimizing various components in a system, every small performance increase here and there can add up in a hurry. The weatherstrip also eliminated the air blowing back out of the mesh front panel.