The Effect of Water Hardness on Boilers, Closed Loops, & Cooling Towers

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Water Hardness for Boilers, Closed Loops, and Cooling Towers

Does Water Hardness Affect My Boiler, Closed Loop, or Cooling Tower?

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.

120PPM is when water starts to be considered hard

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.

Water Hardness by City and State:

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:

  • Delaware 108 PPM
    • Dover 64 PPM
    • Newark 122 PPM
    • Wilmington 117 PPM
  • Illinois 200 PPM
    • Aurora 130 PPM
    • Chicago 148 PPM
    • Elgin 128 PPM
    • Joliet 388 PPM
    • Naperville 288 PPM
    • Rockford 22 PPM
    • Springfield 115 PPM
  • Indiana 262 PPM
    • Bloomington 339 PPM
    • Carmel 137 PPM
    • Evansville 134 PPM
    • Fishers 305 PPM
    • Fort Wayne 129 PPM
    • Indianapolis 274 PPM
    • South Bend 349 PPM
  • Kentucky 102 PPM
    • Bowling Green 144PPM
    • Frankfort 190 PPM
    • Louisville 102 PPM
    • Lexington 215 PPM
    • Owensboro 175 PPM
  • Maryland 118 PPM
    • Baltimore 185 PPM
    • Frederick 101 PPM
    • Gaithersburg 71 PPM
  • Michigan 380 PPM (Referring to the lower peninsula)
    • Ann Arbor 129 PPM
    • Dearborn 279 PPM
    • Detroit 104 PPM
    • Grand Rapids 380 PPM
    • Lansing 99 PPM
    • Sterling Heights 138 PPM
    • Warren 144 PPM
  • Ohio 155PPM
  • Pennsylvania
    • Allentown 205.4 PPM
    • Bensalem 430 PPM
    • Erie 219 PPM
    • Philadelphia 153.5 PPM
    • Pittsburgh 194 PPM
    • Reading 264 PPM
    • Scranton 259 PPM
  • Tennessee 99 PPM
    • Chattanooga 71 PPM
    • Clarksville 97 PPM
    • Franklin 145 PPM
    • Jackson 47 PPM
    • Knoxville 84 PPM
    • Memphis 45 PPM
    • Nashville 79 PPM
  • New Jersey 106 PPM
    • Edison 232 PPM
    • Elizabeth 232 PPM
    • Jersey City 194 PPM
    • Newark 52 PPM
    • Paterson 211 PPM
    • Toms River 156 PPM
    • Woodbridge 158 PPM
  • New York 62 PPM
    • Buffalo 118 PPM
    • Brookhaven 33 PPM
    • Hempstead 33.3 PPM
    • Islip 2.8 PPM
    • New York City (NYC)
    • North Hempstead 19.3 PPM
    • Oyster Bay 46.3 PPM
  • Washington D.C. 123 PPM
  • Wisconsin 158 PPM
    • Appleton 175 PPM
    • Eau Claire 177 PPM
    • Green Bay 130 PPM
    • Kenosha 140 PPM
    • Madison 325 PPM
    • Milwaukee 137 PPM
    • Racine 131 PPM

Fresh Water and Ground Water Sources

Ground water vs fresh water

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.

Water Impurities in Heating and Cooling Equipment

All natural water contains various types and amounts of impurities. Since impurities in water can cause problems in boilerscooling 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!

Chardon Labs Boiler, Closed Loop, and Cooling Tower Service Contact Information

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Matt Welsh

Matt Welsh is the Vice President and Water Consultant at Chardon Labs. He helps consult a wide range of customers utilizing various methods of water treatment, from chemical to chemical-free approaches, large and small applications, and across a wide range of geographical influences. With 20 years of water treatment experience, including a wide range of troubleshooting and service in potable water and non-potable HVAC and industrial applications, he is an expert in water treatment chemistry for cooling towers, boilers, and closed-loop systems.

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