ARCTIC Freezer 36 CO Single Tower CPU Air Cooler

The ARCTIC Freezer 36 CO is a single-tower CPU air cooler purpose-built for continuous, round-the-clock operation. The 'CO' designation stands for Continuous Operation, and it reflects a key hardware difference from the standard Freezer 36: both included fans use dual Japanese ball bearings instead of fluid dynamic bearings, making them significantly more resistant to heat, dust, and vibration over long duty cycles. The cooler ships with two ARCTIC P12 PWM PST fans arranged in a push-pull configuration. The P-series fans are tuned for high static pressure, which is especially well-suited to dense heatsink fin arrays. Fan speed is PWM-controlled across a range of 200 to 1800 rpm, and drops to 0 rpm when the PWM signal falls below 5%, enabling silent idle periods when thermal load permits. Both fans connect via a 4-pin PWM connector with an included 80 mm splitter cable, so only a single motherboard header is required. The aluminium heatsink features 59 fins at 0.4 mm spacing and is threaded by four copper heatpipes, each 6 mm in diameter, that draw heat away from the CPU contact base. An aluminium top plate conceals the soldered heatpipe ends for a cleaner finish. The fin stack is open at the sides to allow the rear pull-fan to draw supplemental airflow laterally through the heatsink, improving overall thermal throughput. Mounting is handled via an innovative click-in system that eliminates traditional fan clips, allowing fans to be attached or swapped without removing the cooler from the motherboard. The cooler includes ARCTIC's dedicated LGA1851/LGA1700 contact frame, which replaces Intel's stock Independent Loading Mechanism (ILM). This aftermarket frame reduces mechanical stress on the CPU die, PCB, and solder layer under sustained thermal load, and allows direct backplate mounting for more consistent contact pressure. Socket compatibility covers Intel LGA1851 and LGA1700, as well as AMD AM5 and AM4 platforms. ARCTIC rates this cooler at a Performance Index (PI) of 250 and a Noise-Normalized PI (NNPI) of 234. The unit carries a 6-year manufacturer warranty. Verified Specifications: - Product Code: ACFRE00122A - Dimensions: 104 (L) × 126 (W) × 159 (H) mm - Weight: 890 g - Heatpipes: 4× 6 mm Ø, copper - Fin Stack: 59× 0.4 mm, aluminium - Fans: 2× ARCTIC P12 PWM PST - Fan Speed: 200–1800 rpm PWM (0 rpm below 5% PWM) - Fan Bearing: Dual Japanese ball bearings (CO variant) - Current / Voltage: 0.10 A / 12 V DC - Connector: 4-pin PWM + 4-pin plug - Cable: 200 mm + 80 mm splitter - Intel Sockets: LGA1851, LGA1700 - AMD Sockets: AM5, AM4 - PI / NNPI: 250 / 234 - Warranty: 6 years