Reviewed October 1993
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Approximately 55,000 of the 61,000 public water facilities in the United States meet the standards mandated by the Safe Drinking Water Act and administered by the Environmental Protection Agency. Water provided by these systems should not need home treatment unless the water is hard, has disagreeable odors and/or tastes or has other minerals not removed to a satisfactory level by the water treatment. People concerned about the quality of their drinking water or who dislike the way their water tastes or smells, may want to consider using one of the home water treatment devices available.
Three major types of water treatment devices are available -- filters, distillers and softeners.
Distillers can almost purify water and eliminate the need for bottled water. When the distiller is operating, tap water in a tank (often made of stainless steel) is heated to boiling to kill bacteria and viruses. Steam is produced, rises and leaves impurities behind. The steam then enters condensing coils where it is cooled by air or water and is converted back to water. Distilled water then goes into outside storage or is dispensed from an interior storage tank through a faucet.
Distillers vary from small, round units that distill less than one quart (1 liter) of water per hour to rectangular carts 34 inches (86 centimeters) high. These carts are connected to an electrical circuit, have no plumbing and can distill about one-half gallon (2 liters) of water per hour.
Weight varies from five pounds (2 kilograms) for countertop units to 70 pounds (32 kilograms) or more for the carts. Wall-mount brackets are available for some light-weight units.
Distillers are filled in one of two ways -- manually or by a connection to a water supply line. A discharge line from the units can be connected to a refrigerator, water cooler or fountain with a demand pump option.
Permanent water distillers should have a drain opening to remove contaminated water. Two types of drains are available -- a faucet or a pipe to a drain. Faucets facilitate draining countertop units.
Cleaning the distiller varies in frequency with the quantity of impurities in the water. Some manufacturers recommend cleaning the machine after every third distillation. White vinegar may be used by leaving it in the boiling tank overnight, or a special cleaner made by the appliance manufacturer may be used.
Initial
Cost to purchase a distiller is much higher than that for a filtering
device. Small units (capacity: 1-1/2 gallons, or 6 liters) cost $250 or more.
Large units (capacity: 15 gallons, or 57 liters) vary from $450 to $1,500 in
purchase price.
Operating
The wattage rating of the appliance and the local electrical rate determine
the cost to distill one gallon (4 liters) of water.
The following formula can determine the approximate cost of distilling one gallon (4 liters) of water:
Wattage rating ÷ 1,000 x time to distill one gallon (hours) x local electric rate (kWh) = cost per gallon.
Examples of two distillers:
In order to compare the cost of distilling water at home with the cost and convenience of buying bottled water, the following data are necessary.
Table 1
Guidelines for comparing cost of distilled vs. bottled water
| Distiller | Bottled water |
|---|---|
| Purchase price | Cost per gallon |
| Number of gallons of water used | Number of gallons of water used |
| Cost of electricity | Transportation or delivery charge |
| Number of years to be used | Holders for containers to be used |
| Maintenance cost | Miscellaneous items |
If the quality of drinking water used in the home needs improvement because it has disagreeable odors and/or tastes or contains minerals (other than calcium and magnesium) at an unsatisfactory level, the advantages of distillers and filters should be compared before making a purchase decision.
Table 2
Comparison of treatment devices
| Advantages of distillers | Advantages of filtering devices |
|---|---|
| Almost pure water | Lower purchase price |
| Sodium-free water | Variety of designs, sizes |
| High quality water for wet batteries and other uses | Some units can retain distinctive flavor associated with minerals in water |
| No filters to replace | Less maintenance may be required |
GH4863, reviewed October 1993