Insulation Design Programs (Free)

Ever had to select insulation for a new pipe, or estimate the energy losses from pipes and equipment? Or do the economic justification for thicker insulation? Try either of the two free programs in this post.

Try out 3e Plus from NAIMA, the North American Insulation Manufacturers Association. This free program lets you model the energy losses from pipes and tanks, at different windspeeds, different materials, insulation thicknesses, etc. The program also has modules (that I have never personally tried) to translate your calculations into dollars or greenhouse gas emissions. Thereby making it easier to justify the purchase of more insulation!!

Hahaha…but no, sarcasm aside it’s a great little program. Try it out. Unfortunately they do not document the method they are using to perform the calculations. A few observations of my own:

• Some of the modelling choices give the same results. For example, I find that Flat Surface = Tank (Horizontal) = Tank (Vertical) in results
• When I compare the losses of steel or stainless steel pipes, there is a big difference when there is no insulation. But almost no difference with insulation. I think it is because the program is considering the thermal heat gain from the sun, and for bare metal the coefficient is different for the different materials? But if I use the same insulation, the insulation is what the sun sees, not the bare metal
• There is a huge variety of insulation types to choose from
• You can leave the insulation thickness on “vary” and get a table of different thickness amounts. Often, I always leave it on “vary” because that’s faster than picking the thickness
• You can export your results to MS Word files. Open the export file and pick a font with monospacing and a small fontsize, e.g. courier new font size 8, and it will look nice. You can then paste the results into MS Excel and use Data>Text to Columns>Delmitted by Space (check the box “Count multiple spaces as one space”) if you want the table in Excel
• There is no convenient way to do many cases at once. I’ve tried curve fitting results, but the prediction is not very satisfying if there is a wide variety of cases. If you have a ton of cases to run, it may be easier to build yourself a calculation using heat transfer equations
• One time I was forced by a project to use this program on 100s of lines of piping. I made an input code for each case: e.g. Temp 100 Insulation 2″ Material Stainless Steel became “T.100I.2M.SS.” I used the VLOOKUP command in Excel, so at least I could re-use results from identical cases and also collect all my 3ePlus work into one place for easier double-checking

Straight from the web browser

Suppose you do not want to install a new program, or want a second program to check it? Try Pipe Heat Loss Calculation from Shane Tierling’s website. The results are pretty comparable to 3ePlus. Note: It uses Javascript and you may have trouble viewing the program in some browsers.

Data for Insulation Design

Lastly, where do you get the data to put into these programs? Here is where I usually find the data, assuming I am part of a large engineering project:

• For economic calculations (as opposed to safety calculations), the process fluid temperature in the insulation program should be the normal temperature
• If you are worried about a pipe or equipment being hot to the touch, in general ~120°F is about the hottest you let the surface of piping or equipment people may touch get. (Exact limit varies by company)
• Pipe material should be from the line list, or P&ID / pipe specification table
• Insulation material and jacket material should be from the pipe specification, or a project may have a general insulation specification that applies to all pipes
• How much insulation do you add for economic purposes? Normally an insulation study is done, creating a table of insulation thickness vs. pipe size and fluid temperature. The insulation study tries to reach an economic maximum: more insulation increases insulation costs (capital costs and somewhat maintenance costs), but decreases energy costs over time. If there is not time for that, try to find an old study or old look-up table for a similar application
• Ambient temperature and windspeed comes from site climate data (if outdoors) or building services / architectural group’s design basis (if indoors; they will design the fans heaters and chillers to keep within their design basis)
• If you do not have climate data given to you, try to find public data for a nearby weather station. For example, you can get airport weather station data at Wolfram Alpha if you search “Climate XXX” where XXX is the airport code. For indoors,  you might assume they will let it go to a minimum of 60-65°F (a bit under room temperature) and a maximum of 10°F above the maximum outdoor temperature
• If modeling tanks or other equipment, you need to estimate the surface area exposed to the air. You might assume it is a simplified shape, like a cylinder or rectangular prism, as a first approximation. Later, if you know the shape of the shell “head” (end of the cylinder) you can look up accurate surface area and volume calculations in reference books or online