Short answer: A greenhouse fog-cooling system should be designed from outdoor temperature and humidity, target crop condition, greenhouse volume, ventilation, required evaporation, nozzle pressure and droplet data, water quality, pump zoning, drainage, controls and maintenance. Nozzle count alone does not define cooling performance.
Fog cooling depends on available moisture capacity in the air and enough time and mixing for droplets to evaporate. High outside humidity can limit temperature reduction and increase wetting risk. Use site temperature and humidity profiles by production season instead of one extreme temperature.
Clarify whether the system reduces daytime temperature, raises humidity, supports propagation or works with ventilation and shading. Crop and stage influence acceptable leaf wetting and humidity. A nursery mist system and a high-pressure climate fog system are not interchangeable.
| Data item | Buyer check |
|---|---|
| Nozzle flow | At what operating pressure and tolerance is it stated? |
| Droplet distribution | What test method and operating condition support the data? |
| Pump duty | Does flow and pressure cover active zones, pipe loss and control range? |
| Nozzle material | Is it compatible with source water, cleaning and greenhouse conditions? |
| Anti-drip device | Does it limit low-pressure dripping after shutdown? |
Place nozzles to distribute fog without wetting crops, electrical equipment or coverings. Consider greenhouse height, air movement, vents, fans, screens and crop canopy. Divide zones by compartment and climate exposure. Pipe supports and thermal movement should prevent vibration and leaks.
Small nozzle passages require clean water. Test suspended solids, hardness, alkalinity, iron, manganese, dissolved salts and microbial risk. Filtration protects particles but does not remove dissolved minerals. Reverse osmosis or other treatment should be selected only from analysis, recovery, reject-water and maintenance considerations.
Too much ventilation can carry unevaporated fog out; too little can trap humidity and reduce evaporation. Shading can lower radiation load and change required fog. The controller should stage fog with vents, fans and screens using inside and outside conditions.
Possible inputs include temperature, humidity, radiation, wind, zone status, water pressure and tank level. Define minimum run and stop times, high-humidity lockout, low-pressure alarm, dry-run protection and manual mode. High-pressure equipment needs guarded components, rated pipe and qualified maintenance.
Flush pipes before installing or opening nozzles
Verify pressure at the pump and remote zones
Observe droplet evaporation and crop wetting under real conditions
Test zone valves, alarms, interlocks and anti-drip function
Inspect filters and record differential pressure
Clean or replace nozzles using approved procedures
Protect the system during shutdown or freezing conditions
Calculate from climate load, nozzle data, zoning, ventilation, greenhouse volume and target condition.
Cooling potential is reduced when air is already humid; wetting and disease risk also require review.
No. Treatment depends on water analysis, nozzle requirement, maintenance, recovery and reject management.
Possible causes include residual pressure, valve condition, anti-drip failure, pressure variation or contamination.
Use the fog cooling category, hot-climate cooling guide and filtration guide.
Send the site climate, greenhouse dimensions, crop, water report and controls through the contact page for a fog-system input checklist.