When spraying cellulose into an attic, a nuisance cloud builds up preventing clear visibility. To reduce this cloud, it is necessary to add a small amount of water to the material so that it weighs down the dust. The internal wetting system adds a small amount of moisture. After the cellulose has been sprayed, the top layer of cellulose creates a thin crust that stabilizes the material in the attic. This helps minimize the material from falling into the access hole opening.
When adding an internal wetting system, you will need to minimize the build up of damp fibers in the hose. We accomplish this in two ways:
- You will need a double-blower machine. The extra air reduces progressive build-up of fiber and gives you an extended range with damp fibers. You should be able to get at least 80% production rate at 150 ft. of hose with this IWS system and double blower feature.
- Another aspect of reducing the plugging in an internal wetting system (IWS), would be going from a 3″ hose up to a 4″ IWS tube and hose for several feet then reducing back down to 3″ for the remainder of your hose length.
Setup Option 1: Connecting to an on-site water source using a standard garden hose
- A: Water supply from either a hose bib or water tank
- B: Power supply: This plugs into the circuit panel on the machine labeled IWS. The power automatically turns on and off with the blower.
- C: Double jet: Two jets introduce a mist of water to the cellulose in a cast aluminum coupler.
- D: A section of 3” hose from the machine, increasing to a 4” hose, then back down to a 3” hose.
Setup Option 2: Carrying water in a storage tank in a truck
- A: Internal Wetting System
- B: Water Pump
- C: 100 gallon Water tank
- Inset: Double blower (identified by two blower controls), and specially wired outlet for the IWS which is synchronized with the blower to start and stop water spray
Frequently Asked Questions (FAQ)
Does the Internal Wetting System make the insulation wet enough to cause mold?
No. The IWS injects a highly atomized, micro-fine mist—not a heavy spray. It adds just enough moisture to weigh down the fine dust particles and activate the natural starches in the cellulose. The minor amount of moisture introduced dries out completely within 24 to 48 hours through standard attic ventilation, poses zero risk of mold growth, and will not damage drywall ceilings.
Can I run the Internal Wetting System with fiberglass insulation?
The IWS is specifically engineered and optimized for loose-fill cellulose. Cellulose fibers absorb the mist uniformly to create a stabilized crust. Fiberglass strands are non-absorbent; attempting to run an inline wetting sleeve with fiberglass can lead to water pooling in the low points of your hose lines, which will cause immediate clogs.
How do I prevent my IWS water pump and lines from freezing in the winter?
Because the system utilizes water lines, freezing temperatures will crack the pump head, water valves, and cast aluminum couplers. During winter storage, you must disconnect the water lines, blow compressed air through the system to evacuate any standing water, or run a small amount of non-toxic RV antifreeze through the pump assembly to protect the internal seals.
What happens if I try to run an IWS on a single-blower machine?
Running a wetting system on a single-blower unit will dramatically reduce your line velocity. Because the single blower cannot handle the physical weight of the damp fibers, the cellulose will slowly build up along the inner ridges of the hose, leading to consistent, frustrating line clogs and a massive drop in production speeds.
