Manual J Load Calculations & Manual S:

Right-CommDuct is a fast, easy-to-use commercial duct sizing and calculation software that takes full advantage of ASHRAE’s precision measurements and duct fitting database. View overview video.


With Right-CommDuct, compute duct and fitting size based on air flow with appropriate velocity limits, and let the software calculate the required fan pressure and total air flow for you. Using the complete built-in ASHRAE database of ducts and fittings allows for accurate commercial duct design to ensure the proper product for the job.

Right-CommDuct has an additional special calculation mode, Existing System, in which you specify the available fan pressure, draw an existing real world duct system, and then specify the actual duct sizes. Right-CommDuct calculates the air flow that will actually come out of each register! You can compare this to the correct air flow, as calculated and diagnose problem systems. Using this approach, you can see what it will take to fix a bad system. When the design air flows match the (modified) actual air flows, you're in business.

Use Right-CommDuct™ to:

Calculate duct sizes based on Equal Friction, Modified Equal Friction, Static Regain, or existing system. More sophisticated than other duct sizing methods, Right-CommDuct will calculate the pressure needed to achieve the targeted Friction Rate, rather than manually readjusting the static pressure to achieve it.

Automatically place registers within a floorplan. Once your floorplan has been established in Right-Draw®, Right-CommDuct will place your registers for you with the click of a button. Right-CommDuct  can also instantly connect branches to trunks to save you time.

Consider “What If” scenarios. Choose to change the friction rate, airflow or fan pressure and the entire system will instantly change to account for the alterations made.

Easily view ducts by system. Right-CommDuct  is color-coded to help define which system you are viewing.

Ensure a properly design system. Let Right-CommDuct be your second set of eyes by highlighting fittings that do not fit together properly.

Automatically size registers.

Automatically layout simple designs.

Additional Technical Features

  • Choose from the following materials and shapes: sheet metal, fiber glass, vinyl flex, metal flex, duct liner and oval, round or rectangular ducts
  • Balance Supply air with return air with a click of a button.
  • Automated layout of commercial duct designs.
  • Contains ASHRAE database of fittings
  • Separate supply trunk and return trunk colors per Air Handler
  • Turn on/off fitting ID’s to avoid any uncertainty during installation.
  • Draw trunk line then click button to have branches auto connect to trunk.
  • Use Special Trunk Move Mode to simultaneously move all branches and takeoffs when moving the trunk line.
  • Analyze engineering details with the Duct Sizing Worksheet.


Right-CommDuct is simply the fastest, easiest and most reliable way to calculate a commercial ASHRAE duct design.


Roquey from Integrity Comfort Solutions says,

"I have used Wrightsoft since the days of monochromatic screens and the spreadsheet-only format. I've attended several classes, been to the World Headquarters in Lexington, and even hosted training classes. The level of support is phenomenal. Both in the classroom, call in and email.

I've used the Right J, Right Draw modules extensively in the new construction markets not only for the purpose intended, but also to "value engineer" the materials selection process for my clients. I can't imagine a better product. The learning curve is pronounced and requires commitment on the part of the user, but with constant use it becomes almost second nature.

As a 40+ year veteran of our industry, I highly recommend this company."

Mike Douglas, from Advent Air Conditioning says,

"As a business owner, one of the things I like is that Right-Draw gives us a level of professionalism whether it’s a specialty home or a basic starter home. Within the past year, we have actually picked up new accounts because our customers were so impressed by the professionalism of our designs, particularly when we go up against contractors who are giving them what amounts to a crayon rendition on a napkin."

Bob Pietrangelo from Comfort Solution says,

"I’ve always been a proponent of proper sizing of air conditioning equipment. For a standard 3,000 square foot, 4 bedroom house, doing the load calculations manually would take many hours. Then I found Wrightsoft, and by using their Right-J and Right-D, I was able to produce load calculations and duct design in about an hour."

Al Gagne from Bayside Mechanical says,

On our Training:
"I've been to three of your trainings over the last 7 years and every time I go I learn something new. The class provides a thorough understanding of Right-Suite® Universal and helpful shortcuts so that I can continue to run my business effectively in this changing market."

On our Software:
"Wrightsoft’s Right-Suite® Universal has helped us to turn bids around faster, especially for custom home builders. I can simply import the AutoCAD building plans as a layer in the program, trace to complete the load calculations and add my ducts to the design, saving me a considerable amount of time. The full design and calculation is then saved in the AutoCAD file as another layer."