An electric water heater offers two distinct advantages over natural gas or propane models: installation is much simpler, requiring only that you properly wire the unit; and the units offer less safety risk, as they don’t require gas. Because of this, you can put an electric water heater almost anywhere in your home or business, without worrying about being close to your natural gas line or propane tank. Gas water heaters require n exhaust pipe to allow unutilized heat to escape. Electric waters are 100% efficient but require constant heating of the elements. For small families, electric may be your best choice as fewer people mean less need for quicker recovery times than a gas unit provides.

High-efficiency gas storage water heaters employ the same technology as standard gas storage water heaters: a glass-lined steel tank is heated by a burner located at the bottom of the tank. But a few basic changes make them operate more efficiently. Many ENERGY STAR-certified models simply have better insulation, heat traps, and more efficient burners, improvements that have a modest impact on price and lead to 8% less energy use. Some very high-efficiency models use a secondary heat exchanger that extracts more heat from the combustion gas, cooling it to the point where there is condensation– hence these types of heaters are called “gas condensing.” These gas-condensing water heaters, like gas-condensing furnaces, require venting through a vertical PVC pipe and a condensate drain. A standard gas water heater usually provides an 80% efficiency rate and requires n exhaust pipe to an existing chimney. High-Efficiency Gas Storage can range up to 96% and can be exhausted using a PVC pipe to the outside. Research showed there are highly engineered systems. This is worth checking into when the need arises.

For people using gas water heaters, two options are offered–natural gas or propane. According to Energy Star, 15 percent of a home’s energy use is attributed to heating water. Both types of gas water heaters offer the same performance in heating. For areas where natural gas is not available, people may choose propane as the source of heating their water. Propane heats water just as well as natural gas but is not as cost-effective. According to the Consumer Energy Center, the yearly cost of operating a natural gas water heater is $190, compared to $343 for propane when the price per therm is 70 cents. Propane will be stored in tanks on your property and require refills from time to time. Propane is a good option for areas without access to a natural gas line, homes not serviced by an electrical grid, or for someone who wants the convenience of quicker recovery heating times (the time it takes to reheat a depleted supply)

• A gas heater can heat a 50-gallon tank in about one hour. Its recovery rate (i.e. time taken to reheat a tank of water after use) is much faster than that of an electric heater. Another advantage of traditional gas water heaters is that they’ll still work in the event of a power outage.
• Tankless water heaters are more efficient than storage tank water heaters in part because there is no standby heat loss. However, one downside to a tankless water heater is the lack of capacity when running more than one hot water tap at the same time
• Tankless Gas has a 10.6 to 11 gallons per minute depending on the fuel, natural gas, or propane. Tankless gas are more efficient than its electric counterpart. Gas units may require annual lookovers.

Solar water heaters come in a wide variety of designs, all including a collector and storage tank, and all using the sun’s thermal energy to heat water. Solar water heaters are typically described according to the type of collector and the circulation system.

• Batch collectors, also called Integrated Collector-Storage (ICS) systems, heat water in dark tanks or tubes within an insulated box, storing water until drawn.
• Flat-plate collectors typically consist of copper tubes fitted to flat absorber plates. The most common configuration is a series of parallel tubes connected at each end by two pipes, the inlet and outlet manifolds.
• The flat plate assembly is contained within an insulated box, and covered with tempered glass.
• Evacuated tube collectors are the most efficient collectors available. Each evacuated tube is similar to a thermos in principle. A glass or metal tube containing the water or heat transfer fluid is surrounded by a larger glass tube. The space between them is a vacuum, so very little heat is lost from the fluid.

• Direct systems circulate water through solar collectors where it is heated by the sun. The heated water is then stored in a tank, sent to a tankless water heater, or used directly
• Closed-loop, or indirect, systems use a non-freezing liquid to transfer heat from the sun to water in a storage tank. The sun’s thermal energy heats the fluid in the solar collectors. Then, this fluid passes through a heat exchanger in the storage tank, transferring the heat to the water. The non-freezing fluid then cycles back to the collectors
• Active, or forced-circulation, systems use electric pumps, valves, and controllers to move water from the collectors to the storage tank. These are common in the U.S.
• Passive systems require no pumps. Natural convection moves water from the collectors to the storage tank as it heats up.