More power, fewer things to go wrong

Why do some watermakers use less power?

A watermaker pushes seawater across a membrane at high pressure, about 800 psi in ours. Most of that water doesn't pass through. It goes back overboard as brine, still under pressure. Energy-recovery designs capture some of that pressure and reuse it, so they need less power for each litre.

Why don't ours?

Recovering that energy takes extra parts under high pressure. We keep the high-pressure side as simple as we can: a commercial-grade pump and a manual regulating valve. That costs more power for each litre, and in return there is less to go wrong.

How much power do ours use?

• DC High-Output: about 56 A at 12.5V (about 700 W) for 70 L/h, or about 28 A at 24V, which is about 10 watt-hours for each litre. Specifications.
• AC: about 13 A at 230V for 80 to 240 L/h, on a generator of 4.5 kW or larger. Specifications.
• Engine Drive: the pump runs off the engine, so the electrical load is only the clutch and the boost pump, about 4 A each at 12V (2 A each at 24V). The pump itself takes up to 2.15 kW (about 3 hp) from the engine. Specifications.

What does that mean on a boat?

Run the DC system for two hours and you'll have about 140 litres, for about 112 Ah from a 12V battery bank. With 1000 W or more of solar, you can run it from peak daytime sun.

With an engine drive or AC system, you make water while the engine or generator is running anyway. Higher output means shorter run times.

Why simpler is more reliable

• Simple manual controls: you start, stop and set the pressure yourself, so there are no surprise cycles or error codes.
• Standard parts you can buy in most cities worldwide, not proprietary ones you have to wait for.
• You can see and hear what the system is doing, and the manual covers most fixes.
• Open Ocean systems have been in service since 2001.

Is it right for you?

If every amp counts and you have little engine or generator time, a lower-power design may suit you better. If you'd rather have a watermaker you can understand and fix anywhere, we'd like to hear from you.