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Browse our latest research and insights below.

The Science of Evaporative Cooling

When water droplets in the 10–30 micron range are released at high pressure (typically 60–80 bar), they flash-evaporate before reaching the ground. The phase change from liquid to vapour absorbs heat from the surrounding air. Studies on evaporative cooling have shown that this process can reduce operative temperature by 3–7 °C in hot, dry conditions, depending on air velocity and humidity (ASHRAE, 2017).

Perceived Comfort & Thermal Environment

Thermal comfort research indicates that people judge comfort using a combination of air temperature, humidity, air speed and radiant temperature (Parsons, 2014). Even when the actual air temperature only drops slightly, increasing air movement and reducing mean radiant temperature around the body can significantly improve comfort votes on standard scales (Havenith, 2019). Directional fans combined with mist take advantage of this by moving the cooled air through the occupied zone.

Real-World Impact in Hospitality

For hospitality operators, a key performance indicator is seat occupancy during the hottest hours of the day. Case reports from outdoor dining areas show that installing high-pressure misting and fans can extend usable trading hours and reduce complaints about heat, particularly during heatwaves (Smith & Lee, 2020). Because the systems atomise water into very fine droplets, correct nozzle spacing and height are important to avoid wetting tables or flooring.

Design Parameters & Best Practices

From a design perspective, important parameters include: pump pressure and flow, nozzle size, mounting height (usually 2.5–3.5 m above floor level), air movement strategy (fans vs still air), and local climate. In hot–dry climates a more aggressive mist level may be acceptable, while in coastal climates with higher background humidity, designers typically use shorter cycles or integrate smart controls to prevent over-humidification.

Overall, high-pressure misting is best understood as a targeted micro‑climate solution. Rather than attempting to air-condition the whole outdoors, it creates pockets of improved comfort where guests sit or queue. When correctly designed and maintained, it can offer a water‑efficient, energy‑efficient method of heat stress reduction for patrons and staff.

Key References

• ASHRAE. (2017) ASHRAE Standard 55-2017: Thermal Environmental Conditions for Human Occupancy. Atlanta, GA: American Society of Heating, Refrigerating and Air-Conditioning Engineers.
• Havenith, G. (2019) 'Thermal comfort, temperature and metabolism in outdoor environments', Building and Environment, 151, pp. 226–238.
• Parsons, K. (2014) Human Thermal Environments: The Effects of Hot, Moderate and Cold Environments on Human Health, Comfort and Performance. 3rd edn. Boca Raton, FL: CRC Press.
• Smith, J. and Lee, A. (2020) 'Evaluating evaporative misting for outdoor restaurant cooling in a subtropical climate', Journal of Building Services Engineering Research & Technology, 41(8), pp. 987–1002.

Optimal Humidity Ranges & Crop Performance

Research suggests that most vegetable and ornamental crops perform best when daytime relative humidity is maintained between roughly 60% and 80%, with short-term excursions tolerated depending on species (Bakker et al., 2019). RH that is too low increases transpiration, leading to water stress and tip burn; excessively high RH reduces transpiration and can create favourable conditions for fungal diseases such as Botrytis.

Vapour Pressure Deficit (VPD) & Fogging Systems

High-pressure fogging adds moisture in the form of very fine droplets (typically <20 microns) that evaporate in the air before reaching the canopy. Because evaporation consumes latent heat, fogging simultaneously cools the air and raises humidity. When combined with roof vents and circulation fans, this allows growers to fine‑tune vapour pressure deficit (VPD), a metric describing the drying power of the air (Stanghellini et al., 2019).

VPD integrates both temperature and humidity and has been shown to correlate well with transpiration rates and stomatal behaviour. Keeping VPD within an optimal range improves photosynthesis efficiency and can shorten crop time. Modern climate computers therefore often control fogging, heating and ventilation with VPD as the primary setpoint rather than RH alone.

Practical Implementation & Results

From a practical standpoint, growers using fogging systems need good water quality and filtration to prevent nozzle blockage, as well as correct nozzle placement to ensure even distribution. Trials in Mediterranean-type climates have demonstrated that well‑designed fogging systems can reduce peak daytime greenhouse temperature by 4–6 °C and increase yield in crops such as tomato and sweet pepper (Willits & Peet, 2018).

By stabilising humidity, fogging also reduces plant stress when external conditions change rapidly—for example, when clouds move away and solar radiation spikes. The result is more predictable growth, improved fruit quality and less physiological disorder. As climate variability increases, active humidity control is becoming a standard rather than a luxury in professional greenhouse production.

Key References

• Bakker, J.C., van Uffelen, J.A.M. and de Zwart, H.F. (2019) Greenhouse Climate Control: An Integrated Approach. 2nd edn. Wageningen: Wageningen Academic Publishers.
• Stanghellini, C., Montero, J.I. and van der Braak, N. (2019) 'Plant responses to humidity and the use of vapour pressure deficit in greenhouse climate control', Acta Horticulturae, 1296, pp. 1–14.
• Willits, D.H. and Peet, M.M. (2018) 'Using fogging to enhance greenhouse cooling in warm climates', Agricultural and Forest Meteorology, 262, pp. 381–390.

The Dust Problem & Traditional Solutions

The U.S. National Institute for Occupational Safety and Health (NIOSH) has documented that respirable dust exposure for haul truck drivers and equipment operators is strongly influenced by road surface moisture and traffic patterns (Organiscak & Reed, 2019). Conventional water trucks typically apply thousands of litres per kilometre, but the effect may last less than an hour under hot, dry and windy conditions.

High-Pressure Misting Alternative

In a trial described in the Dust Control Handbook for Industrial Minerals Mining and Processing, fixed high-pressure spray manifolds were installed at key points such as loading areas and sharp bends where vehicles slow down and dust generation peaks (NIOSH, 2012). Instead of flooding the road, the system produced fine mist curtains that captured airborne dust near its source.

Results & Cost-Benefit Analysis

Monitoring during the trial showed reductions in area respirable dust concentrations of 40–60% compared with periods when only truck-based watering was used (NIOSH, 2012). Because the system delivered smaller droplets at lower total flow, water consumption per treated hour was significantly lower, and road surfaces remained trafficable without excessive mud.

From a cost perspective, fixed spray systems entail a higher upfront investment for piping, pumps and controls, but reduce diesel, labour and maintenance associated with water trucks. The most favourable results occurred where misting was integrated with good road maintenance, appropriate traffic speed limits and, where possible, chemical stabilisers for high‑traffic segments.

Lessons & Best Practices

This case illustrates that high-pressure misting is not a complete replacement for all road watering, but can play a valuable role in reducing peak dust levels in critical zones such as loading points, crushers and intersections. Designing such systems requires careful nozzle selection, pump sizing and consideration of local wind patterns to keep droplets in contact with the dust plume.

Key References

• National Institute for Occupational Safety and Health (NIOSH). (2012) Dust Control Handbook for Industrial Minerals Mining and Processing. Information Circular 9517. Pittsburgh, PA: NIOSH.
• Organiscak, J.A. and Reed, W.R. (2019) 'Haul road dust control strategies for surface mines', Mining Engineering, 71(5), pp. 35–41.

Disinfection Standards & Best Practices

The World Organisation for Animal Health (WOAH, formerly OIE) emphasises that effective disinfection depends on using an appropriate product at the correct concentration, with sufficient contact time and coverage of contaminated surfaces (WOAH, 2022). High-pressure or medium-pressure fogging arches at farm entrances can help achieve this by creating a consistent cloud of small droplets that coat vehicle wheels, undercarriages and external surfaces as they pass through.

Fogging Between Production Cycles

For poultry houses, several studies have evaluated overhead fogging of approved disinfectants between production cycles. When applied after thorough cleaning and drying, fogging can reduce residual bacterial and viral contamination on surfaces and in the air (European Food Safety Authority, 2018). However, fogging is not a substitute for manual cleaning, and organic matter must be removed first to avoid inactivating the disinfectant.

Continuous or high-frequency disinfectant fogging while animals are present is generally discouraged due to welfare and respiratory concerns. Instead, many integrators use water-only fogging for cooling and humidity control during production, and reserve chemical application for downtime between flocks or batches.

System Design & Compliance

For farm operators considering misting-based disinfection, key design questions include: which areas require treatment (vehicle entrances, personnel change rooms, crates, equipment); what throughput is expected; and how to prevent run‑off from contaminating water bodies. Systems should be interlocked with access control so that fogging cannot be bypassed without authorisation.

Regulatory guidance also stresses record‑keeping and verification. Logs of disinfectant type, concentration, maintenance and system performance provide evidence of due diligence during audits or disease investigations. When correctly integrated into a broader biosecurity plan—alongside fencing, controlled entry points, clothing changes and vaccination—misting and fogging can help reduce the risk of pathogen introduction and spread.

Key References

• European Food Safety Authority (EFSA). (2018) 'Evaluation of the efficacy of peracetic acid and other disinfectants for use in poultry houses', EFSA Journal, 16(3), e05204.
• World Organisation for Animal Health (WOAH). (2022) Terrestrial Animal Health Code, Chapter 4.14: Application of Disinfectants. Paris: WOAH.

Air Quality & Health Impact

The World Health Organization estimates that ambient air pollution, particularly fine particulate matter (PM2.5), contributes to millions of premature deaths each year through cardiovascular and respiratory disease (WHO, 2021). While much of this pollution comes from combustion sources, fugitive dust from construction, mining, unpaved roads and industrial stockpiles is an important local contributor. Controlling this dust is therefore both a health and regulatory priority.

Fine Mist vs Traditional Water Application

Traditional dust control methods, such as hosing or sprinklers, often use large droplets that fall quickly and wet surfaces without efficiently capturing airborne particles. Research has shown that droplets of similar size to the dust particles themselves, typically in the 10–50 micron range, are more effective at colliding with and removing these particles from the air (NIOSH, 2012). High‑pressure misting systems are designed to produce such droplets, allowing more dust suppression per unit of water used.

Water Efficiency & Smart Controls

From a water‑resource perspective, fine misting can be substantially more efficient than bulk watering if systems are correctly targeted and controlled. Instead of applying thousands of litres over a broad area, mist curtains can focus water where dust is actually released—for example, transfer points on conveyors, crusher inlets or tipping areas for haul trucks. Automated controls and weather sensors can further reduce waste by adjusting output based on wind and humidity.

Urban Cooling & Sustainable Cities

At the same time, there is growing interest in using similar technology for urban cooling—such as shaded misted walkways, transit stops and public plazas. Pilot projects in Mediterranean and Middle Eastern cities report reductions in perceived temperature and improved outdoor comfort, although designers must manage issues such as slip risk and potential interaction with existing air‑quality problems (Santamouris et al., 2020).

Evidence-Based Design & Future Standards

Looking ahead, industry standards are likely to place more emphasis on evidence‑based design and monitoring. Measuring airborne particle concentrations before and after installation, tracking water and energy use, and integrating data with occupational health programmes will help operators demonstrate both environmental and social value. Fine‑mist systems are not a universal solution, but they offer a flexible tool that can contribute to safer, more comfortable and more sustainable workplaces when combined with good engineering and management practices.

Key References

• Intergovernmental Panel on Climate Change (IPCC). (2021) Climate Change 2021: The Physical Science Basis. Cambridge: Cambridge University Press.
• National Institute for Occupational Safety and Health (NIOSH). (2012) Dust Control Handbook for Industrial Minerals Mining and Processing. Information Circular 9517. Pittsburgh, PA: NIOSH.
• Santamouris, M. et al. (2020) 'Progress in urban heat island mitigation and urban cooling strategies: A review', Renewable and Sustainable Energy Reviews, 139, 110588.
• World Health Organization. (2021) Ambient (Outdoor) Air Pollution. Geneva: WHO.