ASHRAE Radiant Time Series


ASHRAE RTS/CLTD Load Calculations:

Right-CommLoad is based on the internationally accepted ASHRAE heat loss/gain standards (ASHRAE 62 standard ventilation calculations), and supports both CLTD and RTS load calculation methods. This program uses the 24-hour by 12 month ASHRAE Handbook of Fundamentals methods to compute light, medium or heavy heating and cooling loads for an unlimited number of zones. View overview video.


In conjunction with Right-Draw®, Right-CommLoad will rapidly calculate your load once building materials are selected. Right-CommLoad uses a layer-by-layer construction material builder, prebuilt with hundreds of common materials and building components and the option to add materials with custom thermal properties. With our exclusive Hotlink technology, Right-CommLoad will recalculate instantly as you enter figures enabling you to play "What If?" just by changing one value in the easy-to-understand form.

Use Right-CommLoad to:

Build extensive libraries, or use our pre-loaded libraries. These libraries contain hundreds of building material types for building surfaces and offers the ability to create unlimited custom material types. Building material types already within the program range from standard frame materials to structural insulated panels, insulated concrete forms, log walls, encapsulated attics, sealed craws (spray foam/dense packed cellulose applications, and so much more. This program can also can accommodate custom materials which can either be built as layers of components or entered with pre-engineered numbers and can be saved and reused.

Easily assign VAV boxes, air handlers and central plants as you need them. With our easy-to-use drag and drop multi-zone tree, choose to specify equipment type easily. Each space has its own targeted temperature and can be grouped with other spaces simply by dragging from one piece of equipment to another within the multi-zone tree.

View the shape of load peaks and valleys. Right-CommLoad offers a colorful Load Meter which shows the shape of load peaks, not only over 24 hours, but also over 12 months, giving you a full range of possible conditions effecting your load, as well as automatically highlight the peak month and peak hour.

Support custom scenario building. Choose to utilize the included Handbook of Fundamentals Scenarios for common commercial building types like offices, warehouses, churches or restaurants. You can edit Scenarios or create your own.

Edit usage parameters using Schedules. Easily turn on lights at 7AM and then gradually turn them off, starting at 4PM, or whatever contour you choose. This may be applied to people, thermostat settings, plug loads, et cetera. Right-CommLoad also calculates loads for odd usage facilities like a churches or nightclubs, with great accuracy.

Customize building material options used for each project. Make global changes, or change on a case by case basis to material options such as color, shading, delta t, et cetera.

Calculate fresh air requirements using ASHRAE 62 methods. ASHRAE 62 is required by Energy Star and other building codes and programs.

Choose from CLTD or RTS methods.

Additional Technical Features

  • 24-hour by 12 Month ASHRAE load calculations
  • The Latest ASHRAE 12-month design data
  • The Latest ASHRAE ventilation tables from Standard 62
  • Includes ASHRAE’s heat gain from occupants for various activity levels.
  • Built-in library of thousands of material types for building surfaces...RCL also makes it easy for you to use your own special material types.
  • 24 Hour schedules for all Internal Gains and Thermostats
  • Drag & Drop Zoning for VAV, Air Handlers and Plants
  • ASHRAE Internal Gain Table
  • ASHRAE International Weather Data
  • Unlimited Zones, VAV, and Air Handlers
  • Peak Heating & Cooling Loads
  • Metric and US Units


Right-CommLoad is the fastest and easiest way to determine your complete ASHRAE load calculation breakdown for any commercial project. Choose to utilize the custom pie charts to demonstrate to customers their load breakdown for any zone or group of zones.


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."