| Water Heating Devices |
 |
 |
|
Storage or tank-type water heaters are the most common in the American home. They are usually 20- to 80-gallon capacity, and fueled by electricity, propane, oil, or natural gas. These units heat up water in an insulated tank and provide a large amount of water for a short period of time. The disadvantage of these units is that they use energy even when not in operation. The life expectancy of a tank is ten to fifteen years, but can be increased by replacing the tank's internal anode rod. Heat Pump Heaters These units use a heater/compressor and refrigerant fluid to transfer heat from one place to another. They are fueled by electricity, but the heat source is warm air in the vicinity of the heat pump. For this reason heat pumps work best in warm climates. They use less electricity because it takes less energy to move heat than to create it. They are available with built-in water tanks called integral units, or as add-ons to existing water heaters. They are expensive and complicated to install, so it's best to hire a contractor for this job. Indirect Water Heaters Indirect water heaters use the home heating system's boiler. Hot water is stored in a separate insulated tank. Heat is transferred from the boiler via a small circulation pump and heat exchanger. Disadvantages include the fact that it's an integral part of the home heating system and that it's usually easiest to install during new building construction by a contractor. On-Demand Heaters These heaters only go to work when the water is turned on and reaches a minimum flow rate. A gas flame or heater element switches on, heating water as it passes through a radiator-like heat exchanger. These heaters do not store hot water. Tankless water heaters may include many safety features; for example, a certain flow rate may be required in order for the device to turn on; temperature and pressure-relief valves; and additional heat sensors on the heat exchanger, to mention a few. The flow rate itself is limited by the heating capacity of the device. It allows hot water to flow at limited gallons per minute, and increased flow decreases the temperature of the water. At a moderate rate, hot water runs out only when the gas or the water runs out. Most models are fueled by natural gas or propane. Electric models are available but use excessive amounts of electricity. This type of water heater is a good choice for small homes. Solar Water Heaters Solar water heaters (SWH) can be very expensive but there is a quick return on the investment. They tend to be about three times as efficient at harvesting and processing the energy from the sun as photovoltaic systems. There are several types of solar water heater systems, and they work differently depending on the climate. Simple systems are best. All the bells and whistles, sensors, and valves tend to break down. Basic heaters use passive designs with sunlight and heat as the controls. |
Discuss this item on the forums. (0 posts)