Which statement best describes how operating a kitchen exhaust fan with a variable frequency drive (VFD) benefits energy efficiency?

Which statement best describes how operating a kitchen exhaust fan with a variable frequency drive (VFD) benefits energy efficiency?

• A. It ensures the fan always runs at maximum speed.
• B. It guarantees zero maintenance.
• C. It prevents any energy use.
• D. It allows adjusting speed to match demand, reducing energy use and noise.

Answer: (D)

Giving the exhaust fan a variable frequency drive lets you tune the airflow to exactly what’s needed at any moment. The energy a fan uses rises quickly with speed, so running at full blast when it isn’t necessary wastes a lot of power and creates more noise. By matching the fan speed to demand, you cut energy use and reduce noise without sacrificing ventilation where it’s needed. The other ideas aren’t correct because maxing out speed wastes energy, and claiming zero maintenance or zero energy isn’t true. This speed-control approach is the practical way to achieve efficiency and quieter operation in a busy kitchen.

Giving the exhaust fan a variable frequency drive lets you tune the airflow to exactly what’s needed at any moment. The energy a fan uses rises quickly with speed, so running at full blast when it isn’t necessary wastes a lot of power and creates more noise. By matching the fan speed to demand, you cut energy use and reduce noise without sacrificing ventilation where it’s needed. The other ideas aren’t correct because maxing out speed wastes energy, and claiming zero maintenance or zero energy isn’t true. This speed-control approach is the practical way to achieve efficiency and quieter operation in a busy kitchen.