In commercial heating and cooling equipment, water quality is an important factor for the system’s maintenance and efficiency. Water that contains large amounts of the metals calcium and magnesium is referred to as hard water. The amount of hardness in natural water may vary from less than 5 parts per million to over 500 parts per million.
An average surface water supply will contain about 95 ppm of total hardness as opposed to an average of about 200 ppm for groundwater supplies. Since calcium and magnesium compounds in solution are relatively insoluble in water, they tend to precipitate out of solution and form deposits in cooling water systems. Deposits insulate heat exchange surfaces and reduce the operating efficiency of the system. While all impurities found in water must be taken into consideration when used in a cooling system, special attention must be given to hardness.
These mineral deposits are commonly referred to as scale. Scale is a slow-forming deposit of minerals in the water. These harden on the surfaces of boiler tubes, closed-loop piping, cooling tower fill, etc. Oftentimes, scale takes as long to remove as it does to form, so it is important to preemptively treat your heating or cooling system. Both the hardness of the water (dissolved mineral content) and its alkalinity (pH) level affect the amount of scale a system will have without treatment. High levels of hardness or pH will lead to the increased speed of scale formation in your systems.
Each city’s and state’s water hardness will be measured by PPM, or parts per million. 1 PPM is equivalent to 1 mg/L CaCO3. The following data will be the average PPM per city or state:
Fresh water supplies are grouped into two categories, groundwater and surface water. Some of the water reaching the ground seeps down through the surface to the underground streams and lakes and is referred to as groundwater. Water on the surface flows across the soil and collects into brooks, streams, rivers, ponds, or lakes. This source is referred to as surface water.
Because groundwater from shallow or deep wells is in contact with the rocks and soil for a longer period of time as it percolates down through the various layers of soil and rock, it generally contains a higher amount of dissolved solids than does surface water.
Surface water, on the other hand, will contain a higher amount of suspended solids as the flowing water picks up mud, dust, pollen, and other small particles. As pointed out earlier, the types of impurities found in water depend on what the water comes into contact with. The amount that it contains depends on the contact time. The amount of impurities in water is usually measured in parts per million (ppm) by weight.
All natural water contains various types and amounts of impurities. Since impurities in water can cause problems in boilers, cooling towers, and closed loops, careful consideration must be given to the quality of the water used for this purpose.
Rocks and minerals that come into contact with water dissolve due to the solvent quality of water. Water absorbs gases from the atmosphere and soil. It also picks up suspended matter as it flows across or percolates down through the ground. In general, the type of impurities water contains depends on what it contacts. Additionally, the amount of impurities depends on contact time.
The impurities in water can be classified into three broad groups. Dissolved solids are the impurities, primarily minerals, that are in a dissolved state. That is, they do not settle out of solution. Dissolved solids may stain or discolor the water, but remain transparent. Most naturally occurring water contains some calcium carbonate, calcium sulfate, magnesium sulfate, silica, sodium chloride, sodium sulfate, and small quantities of iron, manganese, fluoride, aluminum, and other substances.
Although you cannot control your makeup water quality, you can still treat the water to become just as efficient as “high-quality” water areas. Chardon Labs offers water treatment chemical services to mitigate corrosion, scale, and microbiological contamination. We work with hard water areas like Indianapolis as well as soft water areas like Newark, and everywhere in between! Reach out to us today by clicking here!
