ELECTRIC ON-DEMAND TANKLESS WATER HEATER
Photo courtesy of The Home Depot
An electric on-demand tankless water heater provides time-of-use energy efficient water heating that is up to 34% more efficient than a traditional hot water tanks heater which holds < 41 gallons daily; according to the U.S. Department of Energy (DoE)
The on-demand tankless water heater is heated by copper heating elements only when needed; unlike a conventional electric or gas powered hot water “tank” that consumes power continuously in-order to maintain heated water. Also, additional power consumption is omitted by the absence of a recirculation pump in an on-demand hot water heater.
An electric water heater avoids the potential dangers common with combustion gas powered hot water tanks / tankless heaters such as carbon monoxide (CO) poisoning from blocked air vents and fires if combustible objects come in contact with the flames. However, any hot water tank / tankless heaters has the potential to cause scalding or develop Legionella if improperly operated.
Once the gallons-per-minute (GPM) of the tankless water heater is sized properly to the anticipated flow rate capacity by ground water temperature zone and by the number of faucets & showers flow rate, inconsistent flow rates & temperatures can be avoided. The recommended residential water temperatures to prevent scalding & Legionella is 100 °F to 120 °F. To further reduce the lag time in water temperature—The time the hot water is turned on and reaches point of use—the water heater will be installed close to linear points of priority usage like the shower / ofuro tub & bathroom low flow faucets, combo washer / dryer, then kitchen low flow faucet; respectively.
The recommended maintenance for on-demand water heaters involves descaling of calcium / mineral buildup (Hard water) which can be the achilles heel of any hot water tanks; especially conventional hot water tanks that utilize a sacrificial anode rod. A 5 gallon solution of water & food grade plain vinegar, with a > 5% acetic acid potency, is used to soak then flush the internal water pathway of the water heater. Conventional hot water tanks have an additional six month to annual maintenance water draining to remove sediment that accumulates on the bottom of the tank.
The Tiny Off-Grid House water treatment system removes inlet water impurities before the water even reaches the on-board food grade water storage tank; then subsequently flows to the on-demand tankless water heater, when needed. The 3-stage water treatment system relieves the tankless water heater of the burden of mineralization and bacterial impurities. How: A sediment filter removes particulate matter, a compacted chemical free, acid washed, renewable coconut shells called Granulated Activated Carbon (GAC) block that traps: particulates, herbicides, pesticides, organics chemicals, volatile organic compounds (VOCs) that impact the taste, color and hydrogen sulfide odors in water; along with both free chlorine (Bleach) and chloramines (Bleach + Ammonia NH3) through a process of adsorption—not to be confused with absorption. The third and final stage filter removes lead / iron / manganese; respectively. No chemical agents are added to change the water chemistry, turbidity or odor. The main water source intended for the Tiny Off-Grid House is rain water catchment; however, since water is such a vital resource need for survival the water treatment system can accommodate municipal, river, lake & ground water sources.
For more information please read RAIN WATER CATCHMENT & FILTRATION.
Photo courtesy of The Home Depot
The EcoSmart 11 is a compact 13 Kilo Watt, 2.54 GPM, 240 Volt, on demand tankless water heater. The EcoSmart 11 operational water temperature range is 80 °F - 140 °F / 26 °C - 60 °C. Temperature sensors inside the EcoSmart 11 maintain consistent water temperatures. A standard 100 amperage residential main electrical panel can accommodate the double-pole 60 amperage circuit breaker required to power the EcoSmart 11.
A faucet temperature of 105 °F with an U.S. Zone 1 ground water temperature of 37 °F / 3 °C the EcoSmart 11 is capable of 1.3 GPM; while in the warmer U.S. Zone 9 at 77 °F / 28 °C the EcoSmart 11 is capable of 3.2 GPM.
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