• Spraybooths and sanding operations
• Server rooms
• Processing plants
• Schools
• Offices
• Warehouses
• Air Compressor rooms and plant rooms
• Bakeries
• Restaurants and bars
• Pharmaceutical
• Power turbine cooling

In spraybooths, ambient temperature and humidity can influence productivity both indirectly and directly. Indirectly, hot and dry conditions will reduce productivity through their influence on worker comfort and morale if they are not improved with adequate cooling. Since the surface to be painted has often been in an oven recently, heat stress can be considerable, the more so with inspection lights.

Manufacturing industries frequently require cooling because of the heat produced by equipment. Sufficient cooling improves worker morale, the functioning of equipment, and product quality, resulting in higher and more consistent productivity. Food production is one area in which this is true.

Evaporative cooling systems provide an economical and effective solution. The costs associated with evaporative coolers are many times smaller than those of refrigeration air conditioning systems. In conjunction with a well-designed ventilation system that CFW can design and install, positive pressure, excellent humidity, temperature and airflow control, and conformity to environmental and hygiene regulations can be maintained.

Insect screens can be fitted for hygiene control.

Note that evaporative cooling is not sufficient to keep products and raw materials chilled.

Teaching and learning become unpleasant and unproductive when it is too hot. In places where equipment is operating, such as IT rooms, temperatures can be even higher. Air condition units are often installed to deal with this problem. However, evaporative cooling units are much more cost effective and environmentally friendly in dry conditions.

The comfort of office occupants often suffers because of the density of people in the space, as well as the amount of electronic equipment and insulation in modern buildings.

In hot ambient conditions, warehouses may require cooling for the comfort of workers and to protect products stored in them. Evaporative cooling systems designed to work with the ventilation system of the building can help to accomplish this at low cost, and have relatively low airflow requirements.

In very high temperatures, many compressors will shut down automatically. This occurs when the oil that is used as a heat transfer medium heats up too much, causing it to degrade faster and to solidify. This can lead to blockages in the heat exchanger. Since this heat is eventually dispersed into the air by fans in typical compressors, the problem will be more severe when there is inadequate ventilation or air is merely recirculated.

With an easily installed evaporative cooler, the temperature of plant rooms can be controlled with one thermostat. In a properly ventilated and humidity controlled environment, the cooled air should not cause problems with the drying or compression.

To maximise the shelf life of bread, rusks and other baked goods, the cooling rate must be controlled. If the product cools too slowly, it can succumb to mould earlier than expected. Evaporative cooling can be used to control the cooling rate to optimise the product’s quality.

In restaurants and bars, proper heating and cooling is important to create a pleasant environment for patrons and staff. Refrigeration air conditioning systems are expensive to purchase and operate, and it is preferable not to recirculate air where food preparation is taking place or where occupancy levels are high.

The costs of evaporative cooling are much lower. Energy use is comparatively low, fresh air is introduced into the space, and entrances can be left open if required to welcome customers.

The environment for storing most pharmaceutical products should not reach temperatures of above 25 °C. In some countries, storage is regulated and wholesalers must demonstrate that they have complied with legislation. Regulations might set an absolute maximum temperature as well as mean temperatures over a period.

The expense of refrigeration has led many managers to prefer ventilation for temperature control. However, during heat waves, ventilation may not be sufficient. Evaporative cooling is often the ideal solution to this problem, especially in dry climates.

Combustion turbines (CTs) are commonly used for peak demand power generation because they can start and stop more quickly than commonly used alternatives.

Turbine power output decreases with higher temperatures and fuel efficiency. The total thermal energy available in CT exhaust gases for systems using it for applications such as heating and cooling also decreases. The extent of this effect depends on CT design, with designs using aeroderivative technology (increasingly used for improved performance even in industrial/frame CT design) being especially sensitive to temperature variations. The challenge is exacerbated because the peak-demand power generation that CTs are typically used for is often needed when ambient temperatures are high.

This has led to the use of CTIC (combustion turbine inlet cooling), particularly in areas with hot and dry climates where a proportion of energy use is spent on ventilation and cooling.

CTIC has the following advantages:

• Maximises power output when the demand for and value of electricity is high
• Better fuel efficiency
• Reduces the use of less efficient turbines, reducing costs to consumers
• Reduces the marginal capital costs of additions to capacity.
• Environmentally responsible, reducing fuel use and emissions

Evaporative systems are an ideal solution for CTIC applications, as they are best suited to the environments in which CTIC is most needed. The contact of water with the air passing through the system also helps to reduce particulates, reducing the load on downstream filters and scrubbers.

They are the norm for CTIC as they have the lowest capital cost. They consume considerable amounts of water (which may need to be treated for pad systems) and their effect is dependent on the wet-bulb temperature.

Both wetted media and fogging systems are used. For wetted media, a need for higher saturation means that more media are required and pressure drops increase. This is an established technology. Media may need replacement every 5-10 years depending on water and air quality and hours of use. Proper maintenance is crucial.

Fogging uses a spray of fine water droplets. High-pressure systems can produce droplets of various sizes depending on ambient conditions and desired evaporation rates. They require high-quality water (reverse-osmosis or demineralized water is typical). Nozzles need replacement in 5-10 years due to erosion, and high-pressure pumps need annual servicing or better.

So-called wet-compression/over-fogging/overspray/high-fogging systems spray more water than can evaporate at the inlet, and the water is taken into the CT. This achieves maximal evaporative cooling and also cools the compressor because the additional water is taken into it, reducing the load on the compressor. Total flow rate (by mass) of gas into the CT is increased, further increasing power output.

 For more information, visit www.evapcool.co.za