Types of Water Heaters
Non-condensing units have efficiencies around 80%, meaning around 20% of the heat is wasted and exhausted. Condensing Tankless Water Heaters . Condensing Tankless Water Heaters extract the additional heat from the exhaust gases through various means and therefore exhaust cooler gases, usually around 100 degree F.
Conventional electric heaters utilize a simple heating element to heat the water and a basic storage tank to hold the heated water until it is required. Conventional gas water heaters employ a similar system. With the exception of some fairly recent minor gains in the area of insulation and energy efficiency, they have remained virtually unchanged over the years. While the traditional process of heating is simple, it has some major drawbacks.
Gas and oil water heaters also have venting-related energy losses. Two types of water heaters -- a fan-assisted gas water heater and an atmospheric sealed-combustion water heater -- reduce these losses. Visit the Energy Basics site to learn more about how conventional storage water heaters work.
Direct Circulation Systems. Of the two types of circulation systems for solar water heaters, direct systems—or active systems—are easier to understand. The system is essentially a closed loop that water flows through.
How it Works — Heat Pump Water Heaters (HPWHs) It's generally easier to move something than to make something. Putting that principle to use, HPWHs use electricity to move heat from one place to another instead of generating heat directly. To understand the concept of heat pumps, imagine a refrigerator working in reverse.
Rheem was proud to introduce the first Hybrid Electric Heat Pump water heater to the market in 2009 and we didn't stop there. We have continued to pave the way in this category by increasing efficiency and adding a touch screen control—making it the first water heater ever with a touch screen control.
Indirect Circulation Systems. Indirect circulation systems are more complex. There is a closed loop between your solar collector array and the water storage tank. In that tank is a liquid—usually water mixed with another material, which drops the freezing point.
Solar water heaters -- also called solar domestic hot water systems -- can be a cost-effective way to generate hot water for your home. They can be used in any climate, and the fuel they use -- sunshine -- is free. How They Work. Solar water heating systems include storage tanks and solar collectors.
Most solar water heaters require a well-insulated storage tank. Solar storage tanks have an additional outlet and inlet connected to and from the collector. In two-tank systems, the solar water heater preheats water before it enters the conventional water heater. In one-tank systems, the back-up heater is combined with the solar storage in one tank.
Most tankless water heaters have a life expectancy of more than 20 years. They also have easily replaceable parts that extend their life by many more years. In contrast, storage water heaters last 10–15 years. Tankless water heaters can avoid the standby heat losses associated with storage water heaters.
Tankless water heaters heat water directly without the use of a storage tank. When a hot water tap is turned on, cold water travels through a pipe into the unit. Either a gas burner or an electric element heats the water.