Since energy costs have increased, we are frequently asked whether a wire guard on a fan is necessary. The reasoning that a fan without a wire guard experiences less resistance, and therefore becomes more energy-efficient, is correct. However, removing a wire guard is not always allowed or advisable.
Safety regulations often mandate wire guards to protect both equipment and personnel from accidental contact with moving parts. Additionally, wire guards prevent debris from entering the fan, which could cause damage or reduce its efficiency over time. Below, we explain the considerations in detail to help you make an informed choice that balances energy efficiency with safety and compliance.
Regulation
In some cases, it is mandatory to protect the fan impeller with a wire guard. This is stipulated in various regulations, such as ISO, CE (Europe), and OSHA (USA). Local regulations may differ from the international ISO standard, which is increasingly adopted worldwide. According to this standard, fans installed below 2.7 meters (service level) must have a wire guard.
The type of wire guard depends on local laws and regulations:
- OSHA wire guards: Fixed mesh size of 0.5 inches.
- CE wire guards: Variable mesh size determined by the distance between the wire guard and the fan impeller. The farther the wire guard is from the fan, the coarser the mesh can be.
However, wire guards may not be required when a fan is not freely accessible, such as when it is installed deep within a pipe.
Protection for Both Animals and Fans
In some scenarios, a wire guard is not required but is still advisable. For example, if animals could potentially reach the fan, a wire guard is recommended to protect both the animals and the fan. In rare cases where objects pass through the fan, plastic fan blades have an advantage over metal ones, as they break off to prevent motor imbalance, unlike metal blades that bend, causing imbalance.
Replacement blades or complete impellers are cost-effective and can often be installed within minutes, minimizing downtime.
Energy Savings and Increased Airflow
Removing wire guards can make a fan up to 20% more efficient, though 5–10% is more typical. The efficiency gains depend on several factors:
- A wire guard on the blower side creates more resistance than one on the suction side.
- A wire guard closer to the impeller creates more resistance than one farther away.
- A fine-mesh wire guard creates more resistance than a coarse-mesh wire guard.
- The greater the pressure difference between inside and outside, the more resistance a wire guard introduces.
Examples
Horizontal Circulation Fan
Example: T4E45BAM81100 vs. T4E45BAM80100 (Static pressure: 0 Pa)
With wire guards on two sides:
- Airflow rate: 6,434 m³/h
- Power consumption: 264 W
- Efficiency: 41 W/1000 m³/h
Without wire guards:
- Airflow rate: 6,931 m³/h
- Power consumption: 247 W
- Efficiency: 35.6 W/1000 m³/h
Removing the wire guards improves efficiency by 15.1%.
Panel Fan
Example: V6E50AAM11100 vs. V6E50AAM10100 (Static pressure: 30 Pa)
With a wire guard on the suction side:
- Airflow rate: 4,644 m³/h
- Power consumption: 185 W
- Efficiency: 39.8 W/1000 m³/h
Without a wire guard:
- Airflow rate: 4,799 m³/h
- Power consumption: 182 W
- Efficiency: 37.9 W/1000 m³/h
Removing the wire guard improves efficiency by 5.0%.
Conclusion
Whenever possible, consider installing fans without wire guards to improve efficiency by up to 20%. However, ensure that safety is not compromised and that you comply with local regulations.
Curious about the possibilities for your application? Contact one of our specialists for tailored advice.
