Mineral Buildup / Scaling
Mineral Buildup / Scaling
A common problem with hot water heating systems is the formation of mineral deposits within the heat source. As water is heated, dissolved minerals settle out as solid particles. As the particles build-up on heating surfaces they inhibit heat transfer and increase heating costs. In extreme cases, water heaters can be destroyed due to hot spots in the heat exchanger or restriction of water flow.
These deposits reduce the heat transfer rate to the water, thus reducing efficiency. Under-fired, storage water heaters are hurt the most by scaling. Almost all of the particles that form out of the water settle on the bottom of the tank. The heat transfer surface on the bottom of the tank is coated by layers of the insulating scale and there is no method for removing the build-up.
A deposit of only 1/16 of an inch can reduce efficiency by 20 to 30%. Mineral deposits also cause premature heater burnout and increase maintenance costs. The deposits formed are minerals that precipitate out of the water and deposit onto adjacent surfaces. Mineral deposits occur most heavily at the hottest point in the system, which is most often the heater. As the temperature is increased, more minerals precipitate, creating more deposits. The amount of lime released from water is in direct proportion to water temperature and usage (see chart on the next page). The higher the water usage or water temperature, the more lime deposits are dropped out of the water.
To convert 24.3 grains per U.S. Gallon to parts per million. Read down the TENS column at 20 and across under4 in UNITS line the figure 411. Add to this the .3 in TENTHS column which is 5, for a total of 416
The amount of lime released from water is in direct proportion to water temperature and usage. The higher the water usage or water temperature, the more lime deposits are dropped out of the water. This is the lime scale that forms in pipes, heaters and on cooking utensils.
As the chart indicates; by using 3900 gallons of 160o F. water per day 120 lb. of lime per year would be deposited into your system. An average apartment uses approximately 750 gallons per month. Notice how dramatically this figure drops to 15 lb. per year if your hot water temperature is reduced to 120o F. A 40o F. reduction in temperature reduces lime deposits by 80%. Through the use of EDC Technologies hot water controls your hot water system will be set to operate to a controlled program that will dramatically reduce mineral buildup related to excessive temperature. It pays to keep your water temperature as low as possible by installing EDC Technologies Controls, both by decreasing energy costs and by reducing maintenance costs incurred by a less efficient system due to mineral deposits.