Programs take the guesswork - and homework - out of planning and documenting a radiant system.

Sure, we know you can tie down 5,000 sq. ft. of PEX in an hour. But how fast can you draw your layout on a computer?

Two software programs allow you to very quickly do that and much more, making easy, automated work of layout, pricing and documentation.

While the software programs are relatively new to the market, at least one of the companies has written programs on behalf of various boiler, PEX and other radiant/hydronics manufacturers. Many of those programs are free and will easily do the basics, such as heat load, spacing, maybe even select product (although the products would be limited to the lines of the particular manufacturer).

Here's a rundown on the two products, plus information on software developed by John Siegenthaler:

  • LoopCAD™. Avenir Software Inc.'s LoopCAD, released in May 2003, was the first stand-alone software tool that helped automate the drawing of detailed loop layout drawings for radiant heating systems.

    Prior to that, contractors had to rely on “general purpose” CAD programs that often took a long time to master since they were not created for the type of drawings needed for radiant heat.

    Brad McCrea, Avenir's president, says it took three years to develop the software to automate the drawings Wet Heads needed to perform.

    “The software makes creating floor plan drawings extremely fast, then automatically generates radiant loop designs that are consistent with most manufacturers' recommendations,” he adds. “This is a true CAD design program that is easy to use and focused exclusively on radiant heat.”

    The design process is divided into distinct steps - floor plan creation, joists definition, manifold placement and circuit drawings. Only the tools and options needed are made available at each step.

    Beyond automating the layout, the software takes a bit of the homework out of designing the system. Wet Heads often require loops within a common zone to have lengths equal within 10 percent so that fluid flow rates and heat distribution are properly balanced. LoopCAD's auto-balancing feature will typically generate loop lengths within 5 percent automatically, and with minor adjustments this can often be brought down as low as 1 percent.

    For those truly hard-to-fit rooms, LoopCAD allows contractors to draw loop designs from scratch or at least easily edit the automated drawings.

    McCrea says LoopCAD picks up where many of the manufacturer-specific programs end. “LoopCAD supplements these programs by adding CAD-based drawing capabilities. Rather than being competitive, we are complimentary.”

    McCrea also told us his company is currently working with several manufacturers to integrate the operation of LoopCAD with their specific design programs. Contractors would still have to purchase a LoopCAD license for both programs to work seamlessly.

    LoopCAD also plans on adding 3-D capabilities, snowmelting and integrated heat loss and other calculations later this year.

  • Right-Radiant Plus™. Wrightsoft Corp.'s Right-Radiant Plus, released in August 2004, produces an automated industry-standard design and layout, ASHRAE-based analysis, and CAD-quality drawings produced in a single application.

    Linked to all calculations, any changes made are automatically updated to the drawing itself.

    In fact, the radiant design program, complete with snowmelt capabilities, won an AHR Expo Innovation Award at the 2005 show earlier this year for this unique ability of offering full integration between the drawing and its calculations.

    “Right-Radiant Plus allows contractors to vastly reduce design time, produce accurate CAD-quality loop designs complete with an automatically generated bill of materials and sales proposals, while eliminating the need for other products such as AutoCAD,” says Lisa Skoczylas, marketing communications manager for Wrightsoft. “Contractors can make the adjustments they need to make in one area, and immediately see changes in the redesigned loops, thermal parameters, material list, and the proposal. This instant re-draw ability with calculations, allows a 'what-if' for designers, and makes it easy to refine designs beyond current levels.”

    In computer parlance, this is an “integrated” program; Right-Radiant Plus essentially acts as a “live model,” simultaneously and instantly updating the drawing and other job calculations based on any changes made within the program along the way. With everything integrated, one manual change to the design means any number of automatic changes are made simultaneously to the corresponding layout and job proposal.

    Right-Radiant Plus also offers multiple tubing layouts, variable loop spacing, fixed size panels, handles odd shaped rooms, and can automatically adjust to islands, kitchen cabinets, etc. The program also features the ability to read/write AutoCad files without the user having to own AutoCad.

    Part of a larger program called Right-Suite Residential, Right-Radiant Plus can be completely integrated with all of the other modules without having to switch between programs.

    Beginning with Right-J, a computerized residential load calculation version of the Air Conditioning Contractors of America's printed Manual-J, Wrightsoft has worked with various heating and cooling trade groups to develop HVAC design and sales software since 1986.

    Right-Suite Residential currently “hot links” up to 10 HVAC design and sales functions into one automated program, which includes load calculations, duct design, equipment comparison, proposals, geothermal and radiant loop designs, and a new in-home selling program complete with presentations and sales management abilities.

    As a result, aspects of the other modules could help Wet Heads also factor in any of these options in a radiant system.

    Both companies offer downloadable demos of their products. Check out their respective Web sites for more information:

    Hydronics Design Studio

    PM columnist and engineer John Siegenthaler, P.E., developed Hydronics Design Studio as a “general purpose analytical design assistant.”

    Hydronics Design Studio has the ability to simulate the performance of some radiant systems, and can also be used for estimating fuel costs, designing injection mixing systems, calculating pipe heat loss and sizing expansion tanks.

    As the name implies, the software can also be used on traditional baseboard systems. One component of the Hydronics Design Studio will be given to contractors attending Siegenthaler's popular seminar series, “Modern Engineering Concepts for Hydronic Heating Design.” The “Hydronic System Simulator” will be used during the seminar to design homerun distribution systems.

    In addition to the software, attendees will receive a seminar manual as well as a virtual file cabinet of information on hydronic heating hardware and design data from more than 35 manufacturers.

    This year's seminar includes popular topics from last year's initial series, such as mixing methods, multiple modulating boiler systems, minitube distribution systems, and applications for small variable speed circulators.

    New this year will be discussions on incorporating solar collectors and wood-fired boilers, using Internet-accessible control packages, and designing homerun distribution systems with “Hydronic System Simulator” software.

    The MEC series began earlier this month and continues through July:

      May 25, Baltimore, Md.
      May 26, Philadelphia, Pa.
      June 8, Santa Fe, N.M.
      June 10, Eagle, Colo.
      June 21, Chicago, Ill.
      June 23, Milwaukee, Wis.
      July 13, Portland, Ore.
      July 15, Bozeman, Mt.
    The registration fee is $395 and includes breakfast, lunch and beverages. The course may qualify for continuing education unit credits.

    The seminar is offered by BNP Media, publishers of more than 30 trade magazines, including Plumbing & Mechanical, Supply House Times and PM Engineer. For more information, or to register for the seminar, please visit or contact Keri Wrobel at 888/530-6714.

    For more information on the Hydronics Design Studio software, go to