An external blower, also known as a remote blower, is a type of ventilation fan designed to be mounted within a duct system either between sections of duct or at the end of a duct run to efficiently move air. They are commonly used in HVAC systems, industrial applications, and ventilation systems where space is limited or when a quieter operation is desired. Remote blowers come in various sizes and configurations to suit different airflow requirements and duct sizes. 

There are two different types of remote blowers, Outdoor Blowers or Inline Blowers. Both serve different purposes in ventilation systems:

Installation: Remote blowers are typically installed in remote locations away from the kitchen. This setup helps reduce noise levels in the kitchen, as the blower's motor is not directly above the cooking area.

Power and Performance: Remote blowers are often more powerful than built-in blowers due to their larger size and capacity. They are capable of effectively removing smoke, heat, and cooking odors from the kitchen and exhausting them to the outside.

Quiet Operation: Since remote blowers are installed away from the kitchen, they can provide quieter operation compared to built-in blowers. This is particularly beneficial for homeowners who prioritize a quiet cooking environment.

In summary, while both outdoor blowers and inline blowers contribute to ventilation systems, they serve different purposes and are designed for different installation locations and conditions.