Posted by
led4you on Monday, April 21, 2008 8:56:11 AM
* Storage: The most common hot water system used in homes. Water is kept constantly heated in the storage tank by electricity, natural gas, oil, or propane. Hot water is drawn out of the top of the tank when a faucet is turned on and cold water flows in the bottom to replace it.
* Tankless: Also known as demand or instantaneous water heaters. Water is heated instantly by electricity or gas when water flows through it.
* Solar: Water is circulated from the tank through a solar collector where it is heated by the sun. If the water in the tank is not hot enough, a conventional water heater is used to bring it up to the desired temperature.
Decisions, Decisions
So which type of solar water heater is right for your home? There are several factors to consider including the price of the system and installation, the cost and availability of energy sources, and the energy factor (EF) rating of the water heater.
EF ratings were established by the U.S. Department of Energy to compare the energy efficiency of various products. The EF scale for solar hot water runs from a low of 0.5 for gas storage tank heaters to 2.0 for electric heat pump models. The higher the EF, the more efficient the water heater. The EF number takes into account:
* Recovery Efficiency: How efficiently the heat is applied to the water.
* Standby Loss: The percentage of heat loss per hour of the stored water.
* Cycling Loss: The loss of heat as the water circulates through the unit.