Skip to content
How to Calculate HVAC Ducting

How to Calculate HVAC Ducting

When designing and building a HVAC system, it’s important to make sure that you have the correct size of each component. Whether you’re a seasoned HVAC engineer or a trainee, in this article we’ll cover some essential calculations you need to consider when installing ducting.

Why are these calculations important?

Some people think that bigger means better, but this isn’t the case. The right size ducting is just as important as having the right size components. Imagine the difference between using a straw in a drink opposed to a cardboard tube.

If your HVAC system has been poorly designed it can cause unnecessary pressure or even the failure of the whole system.

Square footage of every room

A common misconception of HVAC calculations is that all you need to know is the total square footage of the building. However, to make sure you’re accurate, you need to know the square footage of each individual room.

The square footage is important because it is vital to ensuring that your system will be powerful enough to circulate the whole building but not so powerful that it causes strain.

Cubic Feet Per Minute (CFM)

The velocity of air needs to be calculated as this is proportionate to the size of the ducting you need. 

Friction Loss Rate

The Friction Loss Rate, also known as the Head Loss Rate, of ducting is important because it is important to ensure you maintain airflow and understand the static pressure of your system.

The equation to calculate Friction Loss Rate is very complex so you will require a certain level of training to use it.

Click here to shop our ducting and grilles! 

Alex Wells

Your cart 0

You currently don't have any items.