HVAC Duct CFM Calculator
HVAC Duct CFM Calculator
Calculate The CFM For Your HVAC Duct And Size Your Systems Properly To Ensure Efficient Heating, Cooling, And Space Ventilation!
Use our free HVAC Duct CFM Calculator above and calculate your system’s airflow capacity Effortlessly.
What Is An HVAC Duct CFM Calculator?
An HVAC Duct CFM calculator helps you calculate the cubic flow per minute of your ducts and determine the airflow capacity of the system. Calculating the CFM will give you the volume of air flowing through the duct per minute.
Why Are HVAC Duct CFM Calculations Important?
HVAC Duct CFM calculations are essential to determining the correct amount of air for each room. These calculations ensure that your system runs efficiently and minimizes the amount of energy wasted due to incorrect duct measurements. They also enable a comfortable room environment and effective cooling and heating of your space.
How To Calculate CFM of Your HVAC Duct?
Our HVAC CFM Duct Calculator accurately measures the volume of air passing through your ducts. It is pretty simple to use. All you need to do is have some data ready for a faster process.Â
What Data Do You Need To Keep Ready Beforehand?
Friction Loss Rate: This refers to the amount of pressure lost per unit length of the duct.
Total Equivalent Length: This refers to the total size of the ductwork system.Â
Duct Type: This refers to the material used for the ductwork. You have two options – metal and flexible.Â
Duct Shape: This refers to the shape of your ductwork. It could be circular or rectangular.Â
Calculation Type: This is where you select whether you need to calculate the CFM or the diameter of your duct system.Â
Diameter: this refers to the diameter of your duct.Â
Side One and Side Two: These are the length and width of your duct, and they are relevant if the duct is rectangular or square.Â
Number of 45-degree Bends: This refers to the frequency of 45-degree bends in your ductwork. These bends create additional airflow resistance, which can lead to pressure loss.Â
Number of 90-degree Bends: This refers to the frequency of 90-degree bends in your ductwork and causes more significant airflow issues.Â
Number of 180-degree Bends: This refers to the frequency of 180-degree bends, also called U-turns, in your ductwork system. Try to minimize these bends, as they can cause significant pressure loss.Â
The Calculation Formula
The formula for calculating the CFM of your duct is = Velocity x Area.Â
To find the velocity, multiply the pressure drop by two and multiply the friction factor and density of air separately.Â
Now divide both the results and find the square root of it.
The formula for finding the velocity:Â
√(2 x pressure drop/ friction factor x density of air ) lb/ft3Â
To find the area, multiply both sides of the duct or divide the diameter by 2, depending on the shape of your duct.Â
Now, calculate the CFM easily by multiplying the velocity by area.
How To Calculate The Diameter Of Your Duct System?
With our HVAC Duct CFM Calculator, you can also calculate the diameter of your duct system.Â
Just select the diameter option from the drop-down menu when you click on the ‘Calculation Type.’Â
The Calculation Formula
To find the diameter, use this formula:Â
If circular: (CFM X 4)/ Ï€ X VelocityÂ
If rectangular: area/side 1. To find the area, the formula is CFM/Velocity
Meanwhile, Check Out Our Other Tools!
ZenTrades offers a plethora of free helpful tools to help you run your field service more efficiently and smoothly.
Check these tools out below!
Flow Rate Calculator: Determine the flow rate of liquids or gases in your operations precisely and efficiently.
Pipe Volume Calculator: Easily calculate the volume of pipes to manage fluid distribution and inventory in field services.
Estimate Generator: Create a Professional and detailed estimate. Add job details and logo, and download for free.
Before-After Image Generator: Create a professional before and after photo of your services quickly
Service Price Calculator: Calculate your service costs and send accurate estimates to your clients.
HVAC Load Calculator: Calculate your building’s energy consumption load for maximum equipment efficiency and performance.
HVAC CFM Calculator: Quickly calculate the airflow requirement and maintain the desired temperature for your rooms.
HVAC Duct CFM Calculator: Calculate the CFM of your HVAC Ducts to ensure appropriate temperature with less energy consumption.
Margin Calculator: Calculate the profit margin of your goods and maintain a superb return on your investment
HVAC Labor Rate Calculator: Quickly calculate the hourly rate of your HVAC technician for each job and maintain your desired profit earnings.
Refrigeration BTU Calculator: Quickly calculate the capacity of your refrigeration unit using our free tool and maintain optimal performance with energy efficiency.Â
ACH Calculator: Calculate your space’s ACH and get an accurate reading of its air change per hour requirements.
General Parts Markup Calculator: Calculate the suitable selling price of your goods and services according to your desired profit range to boost your income.
Sprinkler Velocity: Assess the water velocity of your sprinkler systems and estimate the suitable pipe size to accommodate the water flow.
SEER Energy Saving Calculator: Use this seasonal energy efficiency ratio calculator to Estimate the energy savings potential of your HVAC systems.
Participate In Our Quizzes and Win Amazing Discounts!Â
Fire Alarm Quiz: Think you know fire alarms? Take our quick quiz to learn more about their importance, types, and upkeep—and you might just win a discount on ZenFire!