What Is the Internal Wetting System (IWS)?
The Internal Wetting System, made by Cool Machines, is a retrofit solution that introduces a fine mist of water directly into the material stream as cellulose insulation travels through the hose. Instead of dust escaping into the attic space or settling across a job site, moisture binds to the fibers before they ever leave the nozzle. The result is a noticeably cleaner application — less airborne dust, less cleanup, and a better experience for both installers and homeowners.
Because it’s a self-contained wetting system rather than a full spray foam rig, IWS is designed to bolt onto blowing machines contractors already own, including Krendl machines, without requiring a full equipment overhaul.
Field Testing With Georgia Insulation
To see the system perform outside a controlled setting, we ran a live demonstration in Atlanta, Georgia with the team at Georgia Insulation, who run Krendl equipment on their crews. Watching the IWS system integrate with their existing Krendl setup gave us a clear picture of what a real-world install looks like — from wiring the electronics to dialing in the right amount of water for the material being blown.
One detail worth highlighting: Cool Machines offers IWS in configurations that support various voltages, which matters if you’re running mixed equipment across a fleet or working in a shop with non-standard power setups. That flexibility is part of why the system integrates well across different brands of blowing machines, not just one.
Buyer Beware: Not All IWS Kits Are Complete
Here’s the part every contractor shopping for an Internal Wetting System needs to hear: the IWS system is sold through a number of vendors, including us here at Insulation Machines Net — but not every vendor is selling the same thing. A number of sellers offer only the hardware component of the system, like the tank, tubing, and tip, while leaving out the solenoids and electronics that actually control water delivery.
Without those components, you don’t have a functioning wetting system — you have parts of one. Before you buy, ask specifically whether the kit includes the solenoid valve and control electronics, not just the plumbing. It’s an easy detail to overlook until you’re standing in the attic wondering why nothing is happening when you pull the trigger.
Matching Tips to Your Material
During the Atlanta demo, Georgia Insulation was running a cardboard-based cellulose product, which behaves differently than standard newspaper-based cellulose when it comes to wetting. Cardboard-based material generally needs a higher volume of water to reach proper saturation.
That’s why, when you’re ordering an IWS system, it pays to think ahead about tip selection. A setup built with only a newspaper-product tip in mind may under-saturate a cardboard-based material, while a tip designed for heavier water volume may over-wet a newspaper product. Having a couple of tip options on hand — one suited to higher-saturation cardboard products and one for standard newspaper products — lets your crew adjust on the fly depending on what material is loaded that day, rather than guessing or settling for inconsistent results.
See the Full System in Action
Below, you’ll find video walkthroughs covering the components that make up a complete IWS system, along with a look at how the system is set up on a Krendl machine in the field. If you’re evaluating IWS for your own crew, these are worth watching before you buy — they’ll help you spot the difference between a complete kit and a partial one.
Have questions about whether IWS is the right fit for your setup, or want help making sure you’re getting a complete system? Reach out to our team — we’re happy to walk through your options.
Frequently Asked Questions
What does the Internal Wetting System (IWS) actually do?
The IWS introduces a fine water mist directly into the cellulose material stream as it moves through the hose, binding dust to the fibers before it leaves the nozzle. This significantly reduces the dust generated during attic and dense pack applications.
Will IWS work with my Krendl machine?
Yes. IWS is designed as a retrofit system that integrates with blowing machines contractors already own, including Krendl machines. Cool Machines also offers configurations for various voltages, which helps it fit into different shop setups.
Why do some IWS kits not work as expected?
Many vendors sell only part of the IWS system, such as the tank and tubing, without including the solenoids and electronics needed to control water delivery. Without those components, the system can’t function as a complete wetting solution. Always confirm the kit includes the full electronics before purchasing.
Does the type of cellulose I use affect how IWS is set up?
Yes. Cardboard-based cellulose typically requires a higher volume of water to reach proper saturation than newspaper-based cellulose. It’s a good idea to have more than one tip option on hand so your crew can match water output to the material being blown that day.
Where can I buy a complete IWS system?
IWS is available through several vendors, including us at Insulation Machines Net. When comparing options, ask specifically whether the solenoid and control electronics are included, not just the tank and plumbing components, so you know you’re getting a complete, working system.
