ACCA Manual D

Perpetual License Sales Ending March 1, 2024


As Wrightsoft continues to evolve, we're making a pivotal shift in our licensing model. Effective March 1, 2024, we will no longer offer perpetual licenses for purchase. While existing perpetual licenses will remain functional, they will no longer receive updates or technical support after their WSS (Software and Support) component expires. Click HERE to learn more. 

Manual D Duct Designs:

Right-D® is a fast, easy-to-use residential duct sizing and calculation software that takes full advantage of ACCA's and ANSI’s standard Manual D Method. A proper Manual D duct design with Right-D® will help to quickly find which fan, coil and filter combinations will work together to achieve optimal results and best suit you and your customer. Simply set your system’s external static and pressure drops, select your duct library, and draw your ducts where you want them. Or choose to utilize one of auto-draw systems. Right-Duct® will select the fittings, measure the actual and equivalent length of the runs and size, calculate the appropriate friction rate for each duct, as well as properly size the ducts for you. View overview video.


In conjunction with Right-Draw®, you may draw your duct design, or simply place the registers where you want them, and allow Right-D® to design your layout for you. Using both of these products together also allows the instant calculation of friction rates of each run with every change made in Right-Draw®. Right-D® features the complete ACCA fitting list, which can be modified and saved in libraries for re-use.

Right-D® Applications:

Automatically size your ducts and registers. This program will choose the right duct sizes for your project based on airflow, static pressure and user selected fittings.

Automatically reduce riser size for 3 or more floors.

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

Automatically add Flex End for sound attenuation. Once your main duct branches are set, easily add flex duct to each supply branch run.

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

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

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

Additional Technical Features

  • Balance Supply air with return air with a click of a button.
  • Duct CFM and sizes will automatically adjust with any load changes.
  • Single zone or multi-zone
  • Multi-zone with or without bypass
  • Multi-zone systems with or without diversity
  • Sheet metal, duct board, corrugated metal, vinyl flex and duct liner
  • Automatic branch splitting, or manual branch-by-branch mode
  • Automatic trunk reductions
  • Automatic resizing for high or low velocity
  • Design for fixed friction rate or variable friction rate
  • Manual includes multiple examples for several systems
  • Drag and Drop duct control for any branch or trunk
  • Hot Linked to Right-J for automatic duct sizing
  • Picture library of more than 400 duct fittings
  • Multi-floor color coded duct designs
  • Flex duct and junction box design
  • Automatic risers and risers for supply and return
  • Scaled actual register shapes
  • Duct fitting shapes by actual type
  • Duct symbols and font control
  • Duct Fittings that may not fit together properly will appear in red helping prevent mistakes out in the field
  • 2-Line design (with purchase of RSR 2-Line design module)
  • 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 saving you time.
  • Use Special Trunk Move Mode to simultaneously move all branches and takeoffs when moving the trunk line saving you time.
  • Size ductwork using one of the following methods: Equal Friction, Modified Equal Friction, Static Regain and Existing System.
  • Analyze engineering details with the Duct Sizing Worksheet.


Right-D® is the ultimate Manual D design program for all skill levels. Simply set and save your preferences, draw your floor-plan with the help of Right-Draw®, and your duct design is practically done for you. If you wish to rely on your own design knowledge, you may also choose to design the system manually, and rely on the smart features if ever in doubt. 


Rick Blair Certified Home Energy Rater & Thermographer, Performance Point, LLC says,

"If you're a Wrightsoft user and have been wanting to go to the next level, Right-CAD is it. I'm not conversant with CAD but I was up and running with 3D almost immediately, importing some of my more complex duct designs already created with RSU, and amazed at seeing what I could only imagine before. The 3rd dimension takes the guesswork out of interstitial duct runs, navigating dropped ceiling areas, dropped girders, etc.

Learning curve is simplified by utilizing the familiar tools & tabs already within RSU, and yet with lots of bells and whistles for rainy day exploration and further fine tuning of design presentation. I see this as the future of professional & field ready HVAC design, without the cost and lengthy learning curve of Revit."

Mac owner of Michigan Energy says,

"This company is awesome. The software is pretty easy to use given it's complexity but the real benefit is the service.

Tech support is friendly and patient, the 10 day training course was perfect for a novice user and the trainer was open and understanding - the kind that doesn't make you feel stupid and knows his stuff so well he can explain why the software is doing what it is doing.

A great overall experience!"

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."

Mike Truitt Resnet Rater from This Efficient House says,

“Hands down, the best tool for the job. Our HVAC partners love the 2-line mode drawings, and the export to REM/Rate module saves me at least 2 hours per project! That's a real game changer for us in terms of billable hours and revenue. Mike (sales) and Donald (tech support) have been there for us for over 10 years! Keep up the good work and thanks again guys. - Just another loyal happy customer.”

Jim Heinz President of Heinz Air Conditioning and Heating, Inc. says,

“We are primarily a residential replacement air conditioning and heating company in Clearwater, Florida.  We found a serious issue with improperly sized air conditioning systems in existing homes that was causing issues with humidity, or lack of cooling.  We have used Manual J for over 30 years, but due to the time-consuming process of entering information manually, it was not done unless we had a consumer complaint.  We partnered with Wrightsoft over 15 years ago and can now do a Manual J Load Calculation in less than 30 minutes. Wrightsoft is always there for us, with tech support staff that answers the phone quickly, and offer advice when needed.  There is also a library of how to videos available 24 hours a day on their website. Wrightsoft has continued to be the best option for us for Manual J load calculations.”

Tim Kohut Director of Sustainable Design, National Community Renaissance says,

“I reached out to technical support [to complete an advanced task].  [Technical support] responded within an hour or two, guided me through the process, and even QC’d my spreadsheet (making corrections needed).  I was really impressed… I’ve found that my questions are always answered, usually within hours, and there’s never an attempt to dodge an issue. Wrightsoft’s responsiveness on the support side is what truly sets you apart.  Your team has made my life easier and using RSU has become an integral cornerstone to the work I do guiding our teams in the design and construction of high performance, soon to be ZNE affordable housing.”

Steve Paxton from Air-Dynamics says,

“I've been using Wrightsoft since the late 80’s. Public Service Company in Oklahoma's "Good Cents" program required an ACCA Manual J load calculation and ACCA Manual D duct design to qualify as a "Good Cents" structure. As long as the information is entered correctly, Wrightsoft takes all of the guesswork out of the equation. It has given me peace of mind and keeps our quality of installation above the rest. I can't imagine doing an install without it, it's as important to us as the rest of the tools on our trucks.”

Tom Tumminelli from Brothers Plumbing, Air & Electric says,

“The Wrightsoft experience has been great from the beginning to end.  Their support staff are patient and professional.  Proper equipment sizing is imperative regarding our customers comfort. We have been able to provide our customers with accurate professional data to backup our proposals awarding us multiple projects over our competitors. Well worth the investment of time and money.”