Air Handling Efficiency Ratings: Defining Efficiency

Air Handling Efficiency Ratings

In the industrial sector, it can feel like efficiency is the only thing we ever talk about. Obviously, it’s important — but in order to maximize the efficiency of our plants and our equipment, we must first understand the definition of efficiency for each piece of equipment, as well as how to measure that efficiency.

Air handling systems are one of the most important parts of an industrial facility, and so keeping them efficient is a top priority for plant managers. But understanding the efficiency ratings of these systems isn’t always as clear cut as it should be. Let’s take a closer look at air handling efficiency ratings and how to define what efficiency actually is.

The Definition of Efficiency

Efficiency isn’t just a subjective term — it’s an actual value that we calculate based on the ratio of theoretical air horsepower to the actual brake-horsepower input to the fan shaft. This equation can be written out as follows:

Ƞt = (AHP/BHP) x 100

Many things can contribute to losses between AHP and BHP, and these contributors may need to be included in the equation, too. If that’s the case, then we might express total efficiency like this:

Ƞt = Ƞh x Ƞv x Ƞm

In this equation, Ƞh = hydraulic efficiency, Ƞv = volume efficiency, and Ƞm = mechanical efficiency.

Each of these components plays a unique role in the definition of efficiency:

  • Hydraulic efficiency accounts for the flow path’s flaws and imperfections.  
  • Volumetric efficiency accounts for shaft seal leakage, as well as recirculation around the fan casing and inlet cones.
  • Mechanical efficiency accounts for the mechanical losses experienced in the coupling, bearing, and seals of an air handling system.

Need an Air Handling Efficiency Partner? Contact ProcessBarron!

When it comes to the efficiency of your mechanical draft fans, nothing makes as much of a difference as partnering with an experienced industrial maintenance company. ProcessBarron is dedicated to working with our clients to optimize their efficiency and minimize downtime. Contact us today for more information!