Water heaters are a type of heating appliance that use heat from water to heat water. This is opposed to the more conventional type that uses steam or oil to heat up water. Domestic water heaters are often used for all sorts of applications. They may be used to heat water just before it goes into a home, for instance, or they may be used in industrial processes to provide high temperatures for a wide range of purposes, like preheating or even drying out large pieces of equipment.
The way water heaters work means that they transfer heat from a liquid (water) to a gas (gas) medium. They do this via a small burner at the base of the unit. A pilot light in the burner ignites the gas valve and transfers the heat from the liquid into the medium. Because it is gas, however, it does have some limited effects on the temperature of the surroundings; namely, because of the relatively low pressure of the medium, the water will not rise very far above the ambient temperature.
As a result, most water heaters are designed with a boiler to control the rate of which the gas moves through the burner. The boiler is usually located in a part of the home such as a basement or garage where temperature and humidity are not excessively problematic. This is because, as mentioned earlier, the burner is not meant to be manually operated and, therefore, a thermostat or other means of regulating the temperature is not needed. Of course, this is not true in all home climates; particularly in tropical and subtropical climates where high humidity can affect the effectiveness of a boiler.
Two types of water heaters are available for homeowners: electrical heaters and gas-fired heaters. Electrical water heaters are the more popular choice, as they tend to be less expensive to purchase and, as noted earlier, can be more easily serviced by a professional. Gas-fired units are much larger and are generally intended for use only in commercial applications. They are, however, more energy-efficient than the electric heater and, as a result, may be better for homeowners who live in temperate but not particularly hot climates.
Another option available for homeowners is a water heaters with a cold water-heater and cold-water-storage tank. Cold water pumps this tank, where the water is heated, directly into the area to be heated. In order to do so, a cold water heater needs to have a cold water pump, and this can be achieved in one of two ways: via expansion valves or via a cold water delivery pipe. An expansion valve is simply a section of piping that expands as water flows through it. A cold water delivery pipe, meanwhile, is like a large diameter pipe with an ice-coated cold-water outlet. Because it is insulated, cold water pipes are much sturdier than expansion valves and are therefore preferred.
Heating an entire home through boilers is another means of providing warmth. Although this method doesn’t provide the same level of heating as other methods, many people prefer its warmth. Boilers can also be fitted into an outdoor fireplace, providing even more warmth to the exterior of a home. These types of water heaters are usually fueled by propane or natural gas, although natural gas boilers are slowly gaining popularity for homes in colder climates because they are cleaner and, unlike oil boilers, require virtually no maintenance.