Plan the Perfect Project with a Few Clicks

A new version of NAIMA’s 3E Plus® software is available to simplify your insulation calculations and design.

Charlie Haack

Charlie Haack is the Vice President of Technical Services for the North American Insulation Manufacturers Association (NAIMA). In this role, he leads NAIMA’s technical committees that encompass insulation products for the residential, commercial, and industrial sectors. Prior to joining NAIMA, Mr. Haack was a Manager at the consulting firm ICF, where he directed a team of engineers and energy analysts performing energy policy analysis and international energy- efficiency studies. He can be reached at

March 1, 2022

The North American Insulation Manufacturers Association (NAIMA) has updated its widely used 3E Plus software. This is the first significant update to the capabilities of 3E Plus since the release of Version 4.0 in 2005. With the new update, 3E Plus continues its mission to simplify the task of determining how much insulation is necessary to use less energy, reduce plant emissions, and achieve cost-effective insulation improvements—which the software helps users calculate.

Since its original development in the early 1960s as a computer card deck, 3E Plus has undergone significant upgrading to ensure platform compatibility and ease of use. It was first developed as a DOS‑based program in the late 1980s, when environmental calculations were added to the program. Based on user feedback, today’s generation of 3E Plus is more comprehensive and user friendly than ever, with improved ability to share projects and materials; a new capability of easily calculating results over a range of input values; and the power to work across Windows PCs, Macs, and mobile devices. The next generation of 3E Plus continues to be free and is available for use at

What Can 3E Plus Do?

3E Plus is designed to help engineers and designers easily calculate the appropriate insulation thickness for any application. The software features several customizable inputs to assess any installation type: pipes, tubes, flat surfaces, ducts, vessels, valves, equipment, and tank shells for both hot and cold applications. This enables users to optimize the amount of insulation for a variety of purposes, including the amount of insulation needed to protect workers from hot piping (Personnel Protection) or the insulation levels needed to stop condensation on cold piping (Condensation Control). Perhaps the most-used calculations are the ones that help designers optimize projects with the most cost-effective amount of insulation to apply (Heat Loss per Hour and Economic, Thickness tables). 3E Plus also calculates the avoided greenhouse gas emissions using insulation—a feature that is becoming more important as reporting on expected carbon reductions becomes more common.

New 3E Plus Online Platform

The latest update moves 3E Plus to a new online platform that allows for an improved user interface and new capabilities while continuing to perform heat-loss calculations in accordance with the ASTM C680 standard for estimating/determining heat gain or loss. In particular, this update was made with three improvements in mind:

  1. Improved collaboration and material/project sharing,
  2. Streamlining of calculations, and
  3. Improved reporting and more accessible results data.

Here is what users can expect from the newly designed experience.


  • Maintains familiar calculation types from existing 3E Plus. The Personnel Protection, Condensation Control, Heat Loss/Gain, Interface Temperatures, Economic, and Environmental Impact calculation types are all still available in the new version. See the new layout in Figure 1.

  • Calculates over range of inputs. The update adds the new capability of quickly assessing ranges of inputs to calculate results. For example, a user can vary ambient temperature over a range of values for a heat loss calculation to get a better estimate of the heat loss expected throughout a given year. No more clicking back and forth between the results tab and the inputs tab, as many users do in the current version of 3E Plus.
  • Saves calculations and shares projects. The new project structure saves user projects to the cloud and permits users to quickly share their project and results with others via link.
  • Provides enhanced reporting and downloading data capabilities. Users can create formal 3E Plus PDF reports, and the software now includes the ability to quickly download results in a CSV file format. Users can still copy data directly from the results table as well. See how results are displayed and the options for reporting in Figure 2.


  • Standard ASTM material performance automatically added. 3E Plus will now automatically update the thermal performance of ASTM materials as new versions are published.
  • Insulation materials can be added. 3E Plus maintains the ability to add your own insulation performance data for analysis. Users can use paired data (as shown in Figure 3) or a polynomial equation to describe the thermal performance curve as they could in previous versions. However, a new feature in the update is the ability to use a piecewise function. This new feature permits analysis for insulation types that have performance that varies greatly by temperature and cannot be represented by a single polynomial equation (Figure 4 displays this new feature).
  • Easy searching of materials. A new materials section helps users quickly find materials by name, ASTM standard, or temperature limit and add them to a short list for their project.


  • Material and assumption sharing. The updated version offers a new ability to share materials and standard assumptions with a set of users on a project team. Users can now ensure that product performance information is consistent across projects and do not need to be manually input each time.

Insulation Design Done for You

NIA provides 8 different insulation calculators to give you factual design information. Simply plug in your project information and we do the hard work for you. NIA also offers a guide to walk you or your colleagues through the design of your insulation system project.
Our step-by-step guide makes it easy to answer all of the questions and incorporate all of your design considerations. Read more about the Simple Insulation Calculators or the Mechanical Insulation Design Guide at In addition, MICA’s manual offers fill-in illustrations of dozens of aspects of design so you can eliminate confusion and map out your system. Turn to page 32 to learn more.


The updated 3E Plus puts insulation improvements for mechanical insulation front and center, and it makes it easier than ever to assess the potential benefits of insulation. With the passage of the Infrastructure Investment and Jobs Act in 2021, there is a renewed focus on industrial energy-efficiency projects, and insulation has a large role to play. NAIMA looks forward to users discovering the advantages contained in the new version of 3E Plus at