关于热水循环远处的热水器导致浪费热水循环系统使用泵将热水从热水器循环到水龙水，从而将热水的等待时间降低到几乎没有。所有热水流通系统节省水。但是并非所有系统都节省了能源；一些系统实际上会导致更高的能源费用。选择一个按需系统。热水循环系统有三种类型：热态系统，时间和温度系统以及按需系统。按需系统在绿色房屋中最有意义，因为仅在需要时才将热水泵送至使用点，从而最大程度地减少待机损失。它们是通过无线遥控器或运动检测器手动激活的。在粗糙的水管上，这样的系统可以添加便宜，并且可以负担得起的水管系统改装为现有的管道系统。按需系统安装为改装，使用现有的冷水管线作为借助特殊阀门的返回。 Time and temperature systems. Hot water is circulated automatically to anticipate demand with the help of a timer and thermostat. An override allows homeowners to activate the pump at non-scheduled times. While time and temperature systems cut waiting time, they increase standby heat losses. Hot water lines are essentially turned into extensions of the hot water storage tank. They save water but increase net energy use. Thermosyphon systems. These work only in a home with a tank-type water heater located below the hot water taps — for example, in a basement. A continuous piping loop is installed between the water heater and the fixtures, with a return line coming back to the heater after the farthest fixture is served. Because the returning water is cooler than the water in the top of the water heater, a thermosyphon…