Energy efficient water heaters / Green Building & Sustainable Home Renovation Information & Advice

...Water Heat Recovery (DWHR) pipe. These units are vertical copper heat exchangers that replace a section of your main waste stack. As warm shower water flows down the pipe, it pre-heats the incoming cold water headed for the water heater. This can raise the incoming water temperature from 50°F (10°C) to over 75°F (24°C)...

...water heaters on the market, which, rather than heating water with an electric coil as a normal electric hot water tank does, employ an evaporator to extract heat from the air (either interior or exterior) and use it to make hot water. The byproduct of an air-to-water heat pump after it extracts heat is cold air, so wi...

...water heaters , on demand water heaters and  instantaneous water heaters are different names for the same thing - domestic hot water systems that do not include the storage tank that comes with traditional water heaters.  This type of water heating system can be advantageous in some climates, provided they use gas-fire...