# computer fan

> any fan inside or attached to a computer case used for active cooling

**Wikidata**: [Q3182696](https://www.wikidata.org/wiki/Q3182696)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Computer_fan)  
**Source**: https://4ort.xyz/entity/computer-fan

## Summary
A computer fan is any fan located inside or attached to a computer case, utilized for active cooling and ventilation. It serves as a critical hardware component that prevents overheating in parts like the CPU, graphics card, and power supply unit. These fans operate via specific connectors and voltages, typically ranging from 40mm to 200mm in width.

## Key Facts
*   **Definition:** A computer fan is defined as any fan inside or attached to a computer case used for active cooling.
*   **Classification:** It is a subclass of computer hardware and electric fan.
*   **Standard Widths:** Fans are manufactured in standard widths of 40mm, 60mm, 80mm, 92mm, 120mm, 140mm, and 200mm.
*   **Operating Voltage:** Desktop computer fans typically operate at 12 volts, whereas laptop fans generally operate at 5 volts.
*   **Common Connectors:** They frequently use 3-pin or 4-pin fan connectors; Molex and USB 2 Standard-A plugs are used rarely.
*   **Components:** A fan consists of a rotor, housing, and electrical cable, and often includes a tachometer using a Hall effect sensor.
*   **Integration:** Fans are integral parts of graphics cards, CPU coolers, and power supply units.
*   **Compliance:** 4-pin fans comply with the "4-Wire Pulse Width Modulation (PWM) Controlled Fans" specification.

## FAQs
### Q: What is the primary use of a computer fan?
A: The primary use of a computer fan is active cooling and ventilation for computer hardware. It ensures that components within the computer case do not overheat.

### Q: What are the standard sizes for computer fans?
A: Computer fans come in standardized widths measured in millimeters. The most common sizes include 40mm, 60mm, 80mm, 92mm, 120mm, 140mm, and 200mm.

### Q: How does a laptop fan differ from a desktop fan in terms of power?
A: Laptop fans typically operate at 5 volts, while fans designed for desktop computers generally operate at 12 volts.

## Why It Matters
The computer fan is an essential component of modern computing architecture, serving as the primary mechanism for active thermal management. Without these fans, the heat generated by processing units, graphics cards, and power supplies would accumulate, leading to hardware failure, throttling, or permanent damage.

By facilitating ventilation within the computer case, fans allow for the sustained high-performance operation of complex hardware. Their evolution has included the integration of tachometers and compliance with Pulse Width Modulation (PWM) specifications, allowing systems to dynamically adjust cooling speed based on real-time thermal data. This balance of cooling and noise control is vital for maintaining the longevity and reliability of computer systems.

## Notable For
*   **Active Cooling Implementation:** It is the standard hardware solution for active cooling within computer cases.
*   **Standardized Dimensions:** Unlike many proprietary components, fans adhere to strict standardized widths (40mm–200mm) ensuring broad compatibility.
*   **Sensor Integration:** Modern fans often feature built-in Hall effect sensors acting as tachometers to report rotational speed to the system.
*   **PWM Compliance:** The 4-pin variant specifically complies with the "4-Wire Pulse Width Modulation (PWM) Controlled Fans" specification for precise speed control.

## Body

### Definition and Classification
A computer fan is a hardware component classified as a subclass of both **computer hardware** and **electric fan**. It is defined technically as "any fan inside or attached to a computer case used for active cooling." It serves a dual function of general **ventilation** for the computer case and specific **active cooling** for internal hardware.

### Physical Specifications
Computer fans are characterized by their standardized widths, which are measured in millimeters. The established standard sizes include:
*   40mm
*   60mm
*   80mm
*   92mm
*   120mm
*   140mm
*   200mm

Physically, the unit comprises a **rotor**, a **housing**, and an **electrical cable**. Many units also contain a **tachometer** utilizing a **Hall effect sensor** to monitor performance.

### Electrical and Connectivity
The electrical requirements of a computer fan differ based on the host device:
*   **Desktop Computers:** Typically utilize fans operating at **12 volts**.
*   **Laptops:** Typically utilize fans operating at **5 volts**.

Connectivity is achieved through several interfaces. The most frequent connectors are the **3-pin fan connector** and the **4-pin fan connector**. Less frequently, fans may connect via a **Molex connector** or, rarely, a **USB 2 Standard-A plug**. The 4-pin connectors specifically comply with the **4-Wire Pulse Width Modulation (PWM) Controlled Fans** specification.

### System Integration
Computer fans are rarely standalone entities; they are often distinct parts of larger, heat-generating hardware assemblies. They function as components within:
*   **Graphics Cards:** For cooling the GPU and memory.
*   **CPU Coolers:** Paired with heat sinks and mounting brackets.
*   **Power Supply Units (PSU):** For cooling internal power electronics.

They physically and electrically connect with **motherboards**, **computer cases**, **grilles**, and **heat sinks**.

## Schema Markup
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  "@type": "Thing",
  "name": "Computer fan",
  "description": "Any fan inside or attached to a computer case used for active cooling.",
  "sameAs": [
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  "additionalType": "Computer Hardware"
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## References

1. Freebase Data Dumps. 2013