← Field Notes Water No. 35

Build log: the water system

The part that kills pumps, and the cheap fix.

Water systems seem simple until you live with one.

The pump. A 12V on-demand pump runs when a tap opens and stops when it closes. Good ones are pressure-sensing and self-priming. Draw is meaningful while running (often 50–90W) but intermittent — total daily energy is small.

The part people skip: an accumulator tank. Without one, the pump clicks on and off rapidly as pressure fluctuates at a partly-open tap. That cycling is hard on the pump and produces pulsing flow. An accumulator holds a small pressurized reserve, smoothing flow and dramatically reducing cycling.

Filtration in the rig. Two stages worth having: a sediment filter to protect the pump and fixtures, and a drinking-water filter at the tap you actually drink from. Filtering everything to drinking standard wastes filter life on shower and dish water.

Tanks. Insulate and heat-tape anything exposed if you'll see freezing. A split tank or line is a genuinely bad day.

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