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Marine A/C Explained: DC Systems vs Inverter AC (What the Numbers Say) | How the Pros Do It
1 February 2026 · 14 min · 6K views · St. Petersburg
What this video covers
A master electrician compares the performance and power efficiency of an 18,000 BTU Dometic Voyager AC-powered variable-speed air conditioner against an 18,000 BTU Blue Airco Evolution 48-volt DC-powered unit.▶ 2:00 Testing occurred on two 50-foot catamarans, a Leopard 50 and a Voyage 50, in 76-degree water.▶ 3:41 The technician used Testos flow meters and temperature probes to measure supply and return air, while monitoring power draw via Victron equipment and a Fluke clamp meter.▶ 2:40 Both units delivered nearly identical cooling output, averaging between 12,500 and 12,700 BTUs.▶ 10:27 However, the DC-powered Blue Airco consumed 1,050 watts compared to 1,383 watts for the AC-powered Dometic, a difference of 333 watts.▶ 10:24 This efficiency gain equates to roughly 2,600 watt-hours over an eight-hour night, effectively saving the capacity of a 200-amp-hour lithium battery.▶ 10:36 While both systems provide quiet, variable-speed operation, DC units eliminate the need for inverter-load management, allowing simultaneous use of high-draw appliances like microwaves without overloading the inverter.▶ 12:19
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