The On Deck Channelvideo
Marine A/C Explained: DC Systems vs Inverter AC (What the Numbers Say) | How the Pros Do It
February 1, 2026 · 14 min · 7K 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
Boats in this video
More from The On Deck Channel
From The On Deck Channel — see the channel’s boat, crew, and every analyzed video.
The Sailing Directory Newsletter
One email with the fleet's best finds — the moments, boats, and stories worth your watch time. Enter your own address to get your own copy.