Tankless Water Heater

In Europe and Japan, tankless water heaters were always popular. However, they only recently gained popularity in the US. They have several advantages over the conventional tank type water heaters. These water heaters are also called 'on demand tankless hot water heaters' as they provide you hot water on demand. Since, they do not need a storage tank they can be fitted in small spaces as well. Besides, they are more energy efficient than tank type water heaters. Let us see the various features of tankless type water heater in detail.

How Does a Tankless Water Heater Work

Before we get to the working of a tankless water heater, you must know how a tank type water heater works in the first place. Tank type water heater has a large storage tank of varying capacities. Water enters this tank through an inlet and gets heated inside the tank with the help of a heating element. Constant heating is required to keep the water at the desired temperature. This often results in 'standby heat loss', meaning, energy is wasted even when the hot water is not required. On the other hand, tankless type water heater heats water only when there is a demand for it. When you turn the faucet for the hot water, the cold water enters the heating unit through one end. The heating unit is fitted with a heat exchanger, which transfers the heat generated from the heating unit to the cold water, thereby increasing its temperature. As a result, the water that comes out of your faucet is piping hot. The working of a tankless water heater is triggered by cold water that flows through the pipe. These water heaters are powered on electricity or gas.

Pros and Cons

The biggest advantage of these water heaters is energ efficiency. Since, there is no standby heat loss, they can heat more water with same fuel consumption. Thus, you can save hundreds of dollars over electricity bills every year. Similarly, the time required for heating water is also reduced. Conventional tank type water heaters require you to wait until the reservoir or storage tank gets filled with water. However, in tankless heaters, water heating takes place almost instantaneously. Tank type water heaters are often bulky due to the large size of the tank, whereas tankless type water heater takes very little space. Thus, installation can even be done in a small space under the kitchen cabinets or closets.

Tankless water heaters basically come in two types 'point of use' heaters and 'whole house heaters'. Point of use heaters are suitable if you wish to have hot water only at few fixtures. In large houses, you may experience some problems due to lag time. Lag time is the time required for the water to travel out of faucet from the heating point. In large houses, this lag time may be as large as few minutes. As a result, you might end up running water until you get hot water. This results in water wastage, which eventually defeats the purpose of using a tankless heating system. Thus, in large houses, it may be feasible to install more than one system so as to reduce the lag time and increase the efficiency of the water heaters.

Tankless water heaters require certain specifications in your house. You might have to invest in a separate gas line for a large tankless water heating system. Similarly, an electric tankless water heating system may demand a separate electric circuit. Moreover, the initial cost itself is very high, about three times that of a tank type system. However, it also lasts 5 to 10 years longer than the tank system. Tankless type water heaters need running water at the rate of 0.5 gpm (gallons/minute). Although, electric tankless systems do not emit greenhouse gases, gas powered systems do. This is one serious problem. Gas powered tankless systems cost you even more as they need to be serviced at least once a year.

Before buying tankless water heaters, make sure you can indeed benefit from them. Assess the various tankless systems available in the market, against your needs, so as to choose the best water heating system for your home.