As you can probably guess, choosing a power source for your spray foam rig is extremely important. Sizing the SPF generator for your rig correctly is fundamental to avoiding major issues such as frying the machine or underpowering your rig. A poorly made or improperly installed spray foam generator may even start a fire on your rig. Investing in the right power and auxiliary equipment will make a significant difference in your business’s bottom line!

Power and Auxiliary: What You Should Know & What to Invest In

If you are running a compressor, air dryer, AC, heat and other systems in your rig, you’ll need to upgrade your rig generator to make sure it can power everything in the machine.

A machine like a PMC PH-2 or Graco E-20 is a spray foam machine with reduced power requirements. Machines such as these will run off a smaller generator like an 18KW or 22KW, depending on what else you are running in the rig.

A larger machine like a Graco E-30 or PMC PH-25 would require a larger generator like a 30-45KW. The best spray foam generator for these machines may be a combo unit such as a Morse 40/40. These allow you to have plenty of power and air for your rig while saving space since you won’t need a separate air compressor. This is also nice because you can now run cool, fresh air out of your compressor.

You might also want to consider the shore power option. Spray foam rigs run off a three-phase or single-phase power cord. Shore power is a popular option if you are in areas where power is readily available. It’s important to keep in mind that sometimes you won’t have power available on-site. When that’s the case, having a generator on hand will save you time and money.

When building your rig, keep all of this in mind when choosing your power source. Small mistakes can cost your company big money!

Money Saving Tips

  • Size your rig generator appropriately for longevity and fewer electrical component failures.
  • Add up the watts of all your equipment and add 15% to find the correct size.
  • Gas engines run hotter. They must have access to proper ventilation to avoid fires.
  • Diesel engines are more efficient and last longer which is much better for your ROI.

What Happens When You Cut Corners & Choose Cheap Equipment

  • An underpowered SPF generator may cause electrical problems in your rig. The cost of electrical repairs is expensive. You’ll also have to pay for lost labor on a job. Don’t rely on the cheap, undersized rig generator to keep your largest customer happy.
  • Permanently securing your gas generator may not allow for proper ventilation. It costs much less to simply bolt it to the floor, but that won’t matter if your rig burns down due to lack of ventilation. Experienced rig builders know little details like this, so investing in quality labor when you build your rig is the best way to go.
  • Cheap generators can be extremely hard and expensive to service. Don’t lose your largest, hard-earned customer at the hands of an inferior SPF generator.

Considering an SPF Rig but Unsure How to Get Started?

In short, your rig builder should be someone you trust and are completely comfortable with. Avoid going for the easy and cheap options, and invest in a rig that will keep your business growing for many years to come.

A spray foam rig or trailer is a lifelong investment, and cutting corners usually ends up costing you more money in the long run. Talk to the pros. Contact your local IDI Distributor’s expert team to get started!

By: Ken Allison, Director of Business Development

Ken specializes in business development and building science. You can find him at any of our training events around the country helping local contractors grow their business. Contact your local rep about the next training event near you to hear Ken’s advice first-hand.

Read the Full Series:

Read our full rig series to determine what type of rig you should invest in to get the most ROI. Learn about the important factors that should go into your rig purchase decision and how they could affect your rig’s performance on the job and your profitability!

  1. Introducing Our Mini-Series (what you should know about owning a spray foam rig)
  2. Important SPF Rig Weight & Capacity Considerations
  3. How to Choose the Right Air Filtration System
  4. Air Pressure & Volume — Is Your Equipment Sized for Optimal Performance?
  5. Choosing SPF Equipment With the Best ROI
  6. Other Cost-Saving Considerations


Have a question on anything insulation, pricing, or want to place an order? With hundreds of products and countless services, our experts will help walk you through the process of getting ready for your next project. Get in contact with our team today for help and guidance on the right products and best techniques for you and your business.