I like this system. It only produces hot water when you want it. It’s got to be more energy efficient that the hot water tank. The problem is that you need one for everyplace you want hot water. Fortunately for SE Asians, the only place they want hot water is in the showers of hotel rooms. People often don’t have running water in their homes in Laos. Not only that, why would they need hot water? They don’t wash anything in hot water, including themselves. In India, a room with hot water cost extra and then it was a crapshoot as to whether the water would be hot or not. I think those Indians are into mind games, sometimes.