Drinking water has been distilled from sea water since at least about AD 200, when the process was clearly described by Alexander of Aphrodisias.Its history predates this, as a passage in Aristotle's Meteorologica (II.3, 358b16) refers to the distillation of water.Captain Israel Williams of the Friendship (1797) improvised a way to distill water, which he described in his journal.
In chemical and biological laboratories, as well as in industry, cheaper alternatives such as deionized water are preferred to distilled water. But if these alternatives are not pure enough, distilled water is used. If exceptionally high purity water is required, double distilled water is used.
Distilled water is also commonly used to top off lead acid batteries used in cars and trucks. The presence of other ions commonly found in tap water will drastically reduce an automobile battery's lifespan.
Distilled water is preferable to tap water for use in automotive cooling systems. The minerals and ions typically found in tap water can be corrosive to internal engine components, and can cause a faster depletion of the anti-corrosion additives found in most antifreeze formulations.
Distilled water is also preferable to tap water for use in model steam engine boilers and model engines of other types.[citation needed] Mineral build-up resulting from the use of tap water in model boilers can severely reduce the efficiency of the boilers if run for long periods. This build-up is known as boiler scale.
A boiling water distiller. Boiling tank on top and holding tank on the bottom.
Some people use distilled water for household aquariums because it lacks the chemicals found in tap water. It is important to supplement distilled water when using it for fishkeeping; it is too pure to sustain the chemical reactions needed to support an aquarium ecosystem.
Distilled water is also essential for use in cigar humidors. Mineral build-up resulting from the use of tap water (including bottled water) will reduce the effectiveness of the humidor.
In contrast, some home brewers who want to brew a traditional European Pilsner will dilute their hard water with distilled water so as to mimic the soft waters of Pilsen.
Another application was to increase the density of the air to assist early airplane jet engines during takeoff in "hot and high" atmospheric conditions, as was used on the early Boeing 707.
Distilled water is also used in Constant Positive Airway Pressure (CPAP) machines to humidify the air entering the user's nasal cavity, mouth, and throat. Distilled water will not leave any contaminants behind when the humidifier in the CPAP machine evaporates the water.
Distillation removes all minerals from water, and the membrane methods of reverse osmosis and nanofiltration remove most, or virtually all, minerals. This results in demineralized water, which has not been proven to be healthier than drinking water. The World Health Organization investigated the health effects of demineralized water in 1980, and its experiments in humans found that demineralized water increased diuresis and the elimination of electrolytes, with decreased serum potassium concentration. Magnesium, calcium, and other nutrients in water can help to protect against nutritional deficiency. Recommendations for magnesium have been put at a minimum of 10 mg/L with 20–30 mg/L optimum; for calcium a 20 mg/L minimum and a 40–80 mg/L optimum, and a total water hardness (adding magnesium and calcium) of 2–4 mmol/L. At water hardness above 5 mmol/L, higher incidence of gallstones, kidney stones, urinary stones, arthrosis, and arthropathies have been observed. For fluoride the concentration recommended for dental health is 0.5–1.0 mg/L, with a maximum guideline value of 1.5 mg/L to avoid dental fluorosis.
Water filtration devices are becoming increasingly common in households. Most of these devices do not distill water, though there continues to be an increase in consumer-oriented water distillers and reverse osmosis machines being sold and used. Municipal water supplies often have minerals added or have trace impurities at levels which are regulated to be safe for consumption. Much of these additional impurities, such as volatile organic compounds, fluoride, and an estimated 75,000+ other chemical compounds are not removed through conventional filtration; however, distillation and reverse osmosis eliminate nearly all of these impurities.
The drinking of purified water as a replacement for drinking water has been both advocated and discouraged for health reasons. Purified water lacks minerals and ions such as calcium that play key roles in biological functions such as in nervous system homeostasis, and are normally found in potable water. The lack of naturally occurring minerals in distilled water has raised some concerns. The Journal of General Internal Medicine published a study on the mineral contents of different waters available in the US. The study found that "drinking water sources available to North Americans may contain high levels of calcium, magnesium, and sodium and may provide clinically important portions of the recommended dietary intake of these minerals". It encouraged people to "check the mineral content of their drinking water, whether tap or bottled, and choose water most appropriate for their needs". Since distilled water is devoid of minerals, mineral intake through diet is needed to maintain good health.
The consumption of "hard" water (water with minerals) is associated with beneficial cardiovascular effects. As noted in the American Journal of Epidemiology, consumption of hard drinking water is negatively correlated with atherosclerotic heart disease.