Misters & Foggers

Misters and foggers put water into the air rather than onto the ground: fog to cool a house and hold humidity, mist to keep cuttings and seed flats from drying between waterings. On a production nursery they run in short pulses many times a day, so the head, the pressure and the filtration have to be chosen together.

The decision that matters most is droplet size. A fogger in the 55 to 70 micron range hangs in the air and evaporates; a mist sprayer at around 150 microns settles on the media. Pick the wrong one and you either soak the bench or never wet it. Everything else follows from that choice.

Fog for the air or mist for the media?

Foggers are for cooling, humidification and rooting cuttings under saturated air. Netafim's CoolNet Pro is built for propagation: a 65 micron average droplet that creates a zone of saturated humidity around the cutting, at a 30 psi working pressure. Rivulis runs the widest fog range on this page, with a 55 micron droplet at 60 psi on its high-pressure Fogger, 70 microns from the FLF Fogger, and the Super Fogger in medium- and high-pressure versions for cooling, humidification and chemical application. The Senninger Fogger, listed under Hunter, and the Toro Ag fogger range cover the same cooling and propagation work.

Mist sprayers put water on the surface. The Rivulis Rondo Mist Sprayer drops 150 micron droplets over a 6.5 ft wetting diameter, so seed and cuttings are wetted without the large drops a spinner throws. Green Mist and the Senninger upright and inverted misters are the bench-propagation heads; the inverted Senninger is made for overhead drop assemblies. Netafim's VibroNet is the choice for light mist over a whole bench or single bay rather than a rooting zone.

Low-pressure nozzles from Dramm suit hose-end and small-bench work: the brass Fogg-It Nozzle on 3/4 hose threads for spot misting of seedlings, and JetFog two-, four- and five-outlet heads that push straight onto tube. Tavlit's 809 Mister works down to 14.5 psi where line pressure is limited.

What pressure and filtration does the zone need?

Every head here has its own pressure window. Most misters and the propagation foggers sit at 30 to 50 psi: the Senninger foggers and misters, Green Mist, and CoolNet Pro and VibroNet at a 30 psi average. Cooling foggers run higher. The Rivulis Super Fogger is 40 psi in the medium-pressure model and 60 psi in the high-pressure one, the FLF Fogger wants 51 to 72.5 psi, and the Rondo Mist Sprayer is 36 to 58 psi. Dramm's High Pressure Misty Mist Nozzle needs a high-pressure pump and matching filtration and is tapped directly into the pipeline, topside only. A pressure regulator on each zone keeps the heads in their window whatever the pump does upstream.

Orifices this small block on grit a drip emitter would pass. Filtration is specified per head: 80 mesh for the Rondo, 100 mesh for Green Mist, 120 mesh for the Rivulis Fogger and Super Fogger, 150 mesh (100 micron) for the FLF. Put a disc or screen filter at that rating ahead of the zone, finer for pond or sandy well water.

Because these zones run in short pulses, the lateral has to stay charged. Leak-prevention and anti-leak valves do that: the Super Fogger's built-in device opens at 45 psi and closes at 20 on the medium model, the FLF seals at 20 psi, the Rondo assemblies and Green Mist carry an anti-leak valve or low-pressure LPD, and the Rivulis Fogger's LPD gives simultaneous start-up and shut-down across the block.

What goes wrong, and which line should I start from?

The failures we see are usually in the system around the head.

• Filter rated for drip, not fog. A 120 mesh nozzle behind a coarse screen plugs one head at a time.
• No anti-leak valve. Laterals drain onto the bench after each pulse and spend the start of the next cycle refilling. On a cycle timed in seconds that is most of it.
• Spacing copied from another head. Green Mist wants heads no more than 2.5 ft apart, laterals 3 ft apart and within 10 in. of the bench edge, 3 to 4 ft up. The Rivulis Fogger runs laterals 9.8 to 13.5 ft apart for cooling, but 6 to 10 ft with heads 4 to 5 ft apart for pesticide work.
• Minute-based control. Mist zones need a controller that times in seconds.

The lines differ in emphasis. Rivulis covers the most ground: medium- and high-pressure foggers with leak prevention built in, two mist sprayers, and Rondo and FLF assemblies with anti-leak valve, tube and weight. Netafim concentrates on propagation with CoolNet Pro and bench misting with VibroNet. Senninger, listed under Hunter, offers a color-coded upright mister, an inverted mister and a fogger, all in one 30 to 50 psi window. Dramm is the low-pressure end: brass Fogg-It Nozzles, JetFog on tube, and the High Pressure Misty Mist Nozzle for bay cooling. Tavlit and Toro fill in with the 809 Mister and a fogger range. Send us the house dimensions and water source with your quote request.