The owners manuals of home appliances such as steam irons, humidifiers, CPAP sleeping machines and vaporizers generally recommend the use of distilled or Reverse Osmosis (RO) water in their products. The reason is because hard water, which is typical in most of the world’s tap water will leave calcium and magnesium deposits known commonly as scale.
Scale build-up reduces the energy efficiency of your appliance because it requires that the scale be heated up to vaporize the water. The optimum energy efficiency comes when the water in these devices comes directly into contact with the heating element. When scale builds up, it comes between the heating element and the water and absorbs a lot of the energy before it can get to the water. Distilled or RO water has no hardness so it will not leave scale, therefore over the long haul it will protect your appliance. This makes good sense for sustainability, agree?
Well, here is a little secret that will help you use less RO/distilled water while still protecting your device. Obviously, for maximum protection, use the best quality water you can afford. At $1.00 a gallon however for special water, you can also save some money.
In general, in these lower temperature machines calcium scale is not so much of a problem at hardness levels of 2 grains per gallon, or less. 2 grains is equal to roughly 34 parts per million of hardness (ppm). This is also the same measurement as milligrams per liter (mg/l).
So, if you wanted to save money, all you have to know is the hardness of your tap water which, is usually available from your local water authority. Once you know that, you can blend your own low scaling water using a combination of RO/Distilled and tap water.
For instance, imagine that your city water is 100 parts hard. The formula tells us that a combination of 2 parts pure and 1 part tap yields an overall hardness of 33 ppm. The equation for this formula follows. Solve for X, which is the number of portions of pure water that has to be added to 1 equal portion of tap water to yield a non-scaling water.
X = [(Tap Water Hardness / 34 ppm)] – 1
Added Bonus – You can occasionally put some household vinegar into the appliance to dissolve any scaling that may still build up, or that was there before.