Electric, Gas and Oil Water Heaters
In the United States today, conventional storage tank water heaters continue to be the most common type of hot water heater for general residential use. These hot water heaters work by heating and storing hot water in a huge cylindrical tank, for around-the-clock use. More specifically, water is heated in the tank by either a heating element (electric) or burner (gas or oil). When either the hot water faucet is turned on or hot water in an appliance (such as a dishwasher or washing machine) is used, heated water is released from the top of the storage tank, and replaced with cold water. Once the water temperature in the tank has dropped, the heating process repeats.
The type of fuel or energy source employed to heat the water not only affects the cost of operating the heater but also its efficiency. The following presents a basic summary of the electric, gas, and oil models, and the pros and cons of each. Before deciding which type of hot water heater is best for you, it is recommended that you speak with a licensed plumber.
Electric Water Heaters
Electric powered storage tank water heaters heat water directly by using electric elements located inside the tank, and are generally the least expensive tank-type water heaters to purchase and install. Moreover, such models are generally cleaner (since no venting materials or fuel lines are required) easier to maintain than the gas or oil type variety, are relatively unaffected by sediment build-up, and are a good solution where gas and oil are unavailable. On the downside, electric powered storage tank water heaters have higher operating costs than gas or oil models. However, recent advancements in technology (as your plumber can more particularly describe) have made electric water heaters much more efficient than they were in the past.
Gas Water Heaters
Gas-fired storage tank models have a combustion chamber located directly under the storage tank which heats the tank, which in turn heats the water. This type of system provides more hot water, and a faster reheating time than electric water heaters. In addition such models generally have a lower initial purchase and installation cost, have a long “life span”, are easy to maintain, and have lower maintenance/operating costs than electric models.
Oil Water Heaters
Like gas-fired models, oil-fired storage tank models (which have an oil burner attached to the front of the water heater which propels a flame into a different chamber) heat the tank, which in turn heats the water, providing for more hot water, and a faster reheating time, than electric models. While availability is limited due to its fuel source, where obtainable, these heaters come highly recommended in that they are reliable and able to heat water three to four times faster than other fuels, are energy efficient, and offer years of high quality service. However, oil-fired models do have higher maintenance/operating costs than gas-fired models.
In addition, when comparing electric water heaters to gas and oil-fired models it is important to note that, in addition to general standby heat loss (which occurs because water temperature is constantly maintained in the tank, even when a hot water tap is not running), with gas and oil-fired models there is also the problem of venting-related energy losses. The reason for this is that unlike electric water heaters, which do not require venting, gas and oil-fired water heaters must be vented to the outside to remove exhaust gases safely, thus resulting in additional energy loss. As your plumber will tell you, however, such losses can be reduced by a fan-assisted heater or an atmospheric sealed combustion heater.