Choosing FanMist nozzles and mist-ring output

Match output to the application

The nozzle part number identifies its rated water output in pounds per hour at 1,000 psi. The technical guide lists six sizes, identified by the color band on the cap. A larger orifice adds more water; it also requires enough moving air and evaporation space to carry that water.

Calculate the output of the whole ring

Multiply the nozzle rating by the number of active ports. For example, fourteen 7.94N nozzles deliver 111.16 lb/hr, shown as 111.2 lb/hr in the guide. Add the output of all rings to determine the total nozzle demand on the system.

Check the fan’s loading ratio

The guide defines loading ratio as fan airflow divided by mist-ring water output. Its design guideline is greater than 75 CFM for each lb/hr of water. This is a FanMist selection guideline; temperature, existing humidity, placement and obstructions still affect evaporation.

Using the guide’s 10,000 CFM fan example, a fourteen-port ring with 7.94N nozzles has a ratio of about 90:1. The same ring with 10.58N nozzles produces about 148.1 lb/hr and a ratio of 67.5:1, below that guideline. Choosing the largest nozzle is therefore not always the right way to increase capacity.

Pressure, filtration and anti-drip action

The supplied nozzle specification describes a 303 stainless steel body, ruby orifice and included 5-micron filter. The anti-drip mechanism opens at approximately 300 psi; that opening threshold is different from the 1,000 psi operating rating.

At shutdown, the system must depressurize correctly so the nozzles close. Dripping or an uneven spray can indicate a nozzle, filtration or drain-valve issue. Use the troubleshooting guide to identify the cause before replacing parts.

Confirm the thread and quantity

The standard thread in the supplied guide is 10/24 UNC. Confirm the existing ring and any adapters before ordering replacements. The current catalog shows pack requirements, minimum quantities and pricing for each part.

Changes to nozzle size should be checked against both the fan’s loading ratio and the pump-station capacity. IHC can help match the nozzle to the installed system.

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