HVAC is the abbreviated term for Heating, Ventilation and Air Conditioning and finds its use in environments where humidity and temperature must be closely regulated while providing safe and healthy working conditions. HVAC operates on the principles of thermodynamics, fluid mechanics and heat transfer.
In order to maintain comfortable working temperatures in large industrial units cooling towers are used. These cooling towers are evaporative coolers that aim at regulating the temperature by pumping water from the chiller through various coils to the fan which produces the cooling effect. Other cooling tower designs may include spraying water directly into the air stream as in the case of power plants.
Cooling towers have two classifications, namely Industrial and HVAC. Industrial cooling towers reject heat generated from machinery and heated process material. Such cooling towers aim at removing the heat generated by circulating cool water in the system.
HVAC cooling towers reject the heat generated by a chiller. In large settings, water cooled chillers work better than air cooled chillers and HVAC chillers provide better ventilation, maintain thermal comfort and reduce air infiltration while being more energy efficient.
Cooling tower water systems normally flush airborne pollutants and collect dust all of which gather on the heat exchange surfaces and increase bacteriological activity. These contaminants are mainly biocides, silt, pollen, algae or slime, hardness salts and corrosion products. For example, the dissolved solids present in water tend to become more concentrated at some point and result in the formation of scale. It has been noted that Calcium and Magnesium already present in the water constitute less than 2% of the pollutants and the rest of the contaminants are brought in by the cooling tower. Algae growing in the cooling tower basin can prove to be extremely toxic and hazardous for employees and also the environment as this water gets discharged into the public sewers, which ultimately reaches the main water source.
All these products when circulated in the cooling system through the heat exchangers, compressors and chillers significantly reduce the systems cooling ability. It can also result in the complete breakdown of the cooling system or increase its operational cost due to frequent cleaning requirements.
An ideal cooling system looks at filtering 100% of circulated water to 100 micron. This cooling system normally will have a full flow filter and will protect almost all components of the industrial process system. An automatic back washing sand filter will improve chemical effectiveness and increase water quality as well as water clarity.
Water treatment needs are very industry specific. For example in the automotive industry focus will be on high water purity for e-coat and assembly plant paint lines, zero liquid discharge (ZLD), water recovery and wastewater treatment while in the Food and Beverage industry water treatment would include membrane filtration, pretreatment, disinfection and oxygen removal systems.
A permanent water filtration system in a cooling tower reduces pumping needs by approximately 20% and also checks the breeding of micro organisms that are present in the water which can pose a serious environmental threat. Installing such a unit is the best way to eliminate all environmental and safety problems and increase the efficiency of the cooling tower
” benefits of water filtration in industrial hvac tower,” Carbonated Seltzer Water. http://tutorials.carbonatedseltzerwater.com/filtered-water/industrial-water/benefits-of-water-filtration-in-industrial-hvac-tower/ (accessed January 27, 2010).