Tankless Water Heaters
The tankless water heater is a new take on a very old problem. For most of human history, the only way to obtain a usable supply of hot water was to heat up a large amount of it all at once. The process evolved to the point where tank-based water heaters were able to heat a large supply of water and then maintain this temperature on a constant basis so that heated water was always available at any time.
The price of this convenience has to be paid in the amount of energy expended in maintaining the water temperature at all times. Since heat escapes on a constant basis, additional energy needs to be expended on a continuing basis.
A More Efficient Approach to Hot Water
A tankless water heater addresses the problem of hot water from a different direction. Rather than keep a lot of hot water ready at all times, tankless heaters do nothing until demand is indicated by someone turning on the hot water tap.
When that happens, the unit springs into action, rapidly heats the small amount of water inside the system and pushes it out for delivery. Additional water flows in on a constant basis and is heated to the necessary temperature as it makes its swift journey through the tankless heater.
How Tankless Water Heaters Function
If one thinks of a stream of water as containing a series of one ounce increments of liquid, then any system which can instantly heat that ounce in the time it takes to flow through the heater is, in effect, a tankless water heater. Because the hot water created by such a system is not allowed to sit and bleed away its accumulated heat energy before usage, tankless heaters use significantly less energy than traditional systems.
These heaters can run on either gas or electricity. In appearance, they usually look like a simple box with an inlet and an outlet pipe. Inside the box is a series of pipe loops that pass through a high efficiency heat source.
The amount of water that can be heated is rated on a gallons-per-minute basis. Moving too much water too quickly through the unit does not allow it to reach the rated temperature setting before passing out. This is the main difficulty with the design since most people assume that all tankless units produce an endless supply of heated water, which is true, at any rate desired, which is not always true.
Different Functionality for Different Needs
Some heaters are small devices intended for little more than washing one’s hands or drawing a cup of water for tea in isolated areas of the home that are distant from the regular tank-style water heater. An installation that is truly capable of handling any demand, or meeting the so-called “two appliance” standard, is much larger and costs considerably more.
Always opt for a larger size than expected since there is no satisfaction in a device that is not capable of producing at more than a trickle. It takes a very long time to fill a bathtub or washing machine when heating water at 1.5 gallons per minute, which is the output of small ones. A 4.0 gallon per minute heater will be more satisfactory in all cases.