Hot weather cooling for poultry and livestock includes misting or spraying with enough air velocity to encourage evaporation or direct cooling of air via fogging or other evaporative cooling pad as part of a mechanical ventilation system.
Evaporative cooler pads are a great way to reduce the temperature inside a facility. The pads draw hot air from outside through the saturated media. It then absorbs water and cools down. The wet-bulb temperature depression is the difference in temperature between the air and the air wet-bulb temperature. This determines the degree of cooling that can be achieved. Evaporative pads can achieve up to 80% efficiency or higher. Evaporative cooling pads can be a large investment. Regular maintenance is often neglected or not taught to users. Here are some guidelines to help you maintain your pads. These guidelines will allow for many years of use before replacement pads are necessary and will ensure that your pads perform well.
Water quality in an evaporative system is critical. It should have a pH of 6-8. Acidification may be recommended if the pH is higher. You should bleed off some water from the system. Salts and minerals build up as the water evaporates, and these can be left behind in the water. The simplest way to make sure that mineral concentrations are diluted in water is to bleed off the water. If there is not enough bleed-off, then deposits can build up on the surface of the evaporative pads. They reduce the efficiency of evaporation. How much should you bleed off? For a pad 4 feet high and 6 inches thick, follow the manufacturer’s recommendations.
Another thing to be aware of is the dry areas that may occur during system operation. The flow should be sufficient to wet all of the pads. The average flow rate is about 3/4 gallon per foot. The distributor pipe may become clogged if the system is contaminated with algae or scale.
Pay attention to algae. Algae can cause damage to the pad media. As it builds up, it will reduce the airflow resistance and decompose cellulose pad material. Algae control strategies include:
a) Chemical treatment is required
b) Keep the pad and sump area from direct sunlight.
c) Ensure that the pads are completely dry every 24 hours. You can do this in several ways. For example, set the ventilation controller so that it activates the system only at night temperature. Or, put the system on a 24-hour timer to turn off operation for a few hours early in the morning.
Visually inspect the pads for signs of sagging and damage, including bird nests or holes. Dry sections can indicate insufficient flow, a failing pump, or plugged water distribution pipe holes.
You should inspect the sump for any debris such as insects, leaves and tree seeds, grass clippings, dirt, and dust that has been washed into it. This is food for algae to grow so remove it first and then clean out any grass clippings from mowing that has been deposited in the sump.
Scale buildup is something to be aware of. Increase the bleed rate if scale buildup is evident.
Pay attention to the appearance of algae. If you notice algae, adjust your daily drying time or review the chemical treatment methods.
You should drain the system completely and disinfect it. Below is a list of chemical treatments. If pads are left in place year-round, they can accumulate debris and need to be cleaned at the beginning of each season. All accumulated solids must be removed from the distribution pipes and upper assembly.
Guidelines For Chemical Treatment
It is generally recommended to use two treatment methods: continuous and quarterly cleaning, or as necessary. Follow the pad manufacturer’s recommendations. The pad’s life expectancy will be reduced if you don’t add bleach (chlorine), or bromine. For continuous treatment as an Algaecide, compounds containing quaternary ammonium should be used. Compounds that include quaternary ammonium are recommended for cleaning. They also contain an organic acid to lower pH and aid with scaling.