Kingfisher MA37X12 AC runs on 12V DC

COURTESY APS

The Kingfisher MA37X12 AC, a compact and lightweight air-conditioning appliance, runs on 12VDC and has a 3,700 Btu/h capacity.

Archer Power Solutions (APS), a company founded in 2019 and part of the Maryland Energy Innovation Accelerator, is bringing 12VDC-powered air-conditioning to small vessels. The firm’s first product, the Kingfisher MA37X12, is compact (37 x 12/94cm x 30.5cm), lightweight (20 lbs/9 kg), and has a 3,700 Btu/h capacity. It was designed to cool and dehumidify the air in the living quarters of small- to medium-sized boats without the noise and exhaust of a genset. “The amount of power it needs is typically 200 watts,” said company founder Onat Dogruer, who has an MBA, experience as a U.S. Coast Guard Merchant Marine captain, and is an ABYC-certified technician for marine electric, A/C, and refrigeration. “Any sailboat will have two 200-watt solar panels to run the refrigerator, cabin lights, anchor light, and anything else. And the next day you power up your engine…go to your next point of anchorage.”

APS marketing materials claim the Kingfisher MA37X12 is the “only marine air conditioner combining a true DC inverter compressor synchronized with an electronic expansion valve, governed by a custom-designed digital controller,” promising higher efficiency and lower energy needs. The product is tested to the ISO 7547-2002 standard with design conditions and basis of calculations at 95°F (35°C) outdoor air and 89.6°F (32°C) seawater temperatures, specifically for use in the tropics. With an operating range of 9.6V–15V, it is engineered to protect against power module overheating, compressor overload, and overcurrent/short circuiting. The refrigerant is R134a, a known greenhouse gas, which is still widely used and easy to source but will be phased out eventually, so “APS is planning a transition to refrigerants like R1234ze or others, following the industry,” Dogruer said.

The installation is straightforward for licensed marine electricians and achievable for competent DIY boat owners. “You need basic knowledge of 12VDC wiring, and a screwdriver,” Dogruer said. Other useful skills include making crimp terminals, using bug connectors, and having some knowledge of DC bus installation. “ABYC standards absolutely need to be followed,” he added, “especially with wire gauging, which is referred to in the manual. But if you can wire the [DC electric system] on a boat, you can wire this unit.”

COURTESY APS

It fits under the chart table on a 1987 Wauquiez Centurion 38 sailing yacht.

Tripp DeFalco, an architect who owns a vintage 1987 Wauquiez Centurion 38 he keeps in Solomons, Maryland, did exactly that. He said putting the Kingfisher AC in a locker under the chart table, took “roughly 24 man-hours on the installation, plus another 4–6 hours reading the instructions, planning, and ordering supplies.” His boat is wired for 30-amp/120VAC shore power and a 100-amp/12VDC alternator on the diesel engine, and it recently received a new house battery bank of two LifePo4 280-amp batteries.

“Compared to my previous boat, which had typical 120VAC systems, this is much, much quieter,” DeFalco said. “No noise at all from the water pump and only a faint sound from the compressor.” After testing the Kingfisher MA37X12 on a warm weekend with the new battery bank, he reported: “Even though the interior temperature changed very slowly, the humidity level dropped pretty quickly, and the comfort level was very good. The [Kingfisher] is very efficient at removing humidity, and I was very comfortable in the salon, even between noon and 4 p.m., when the sun was strongest. At night I tried cooling the whole boat again (all hatches closed), and the unit did help a bit but struggled to make a meaningful dent in either temperature or humidity. But with the fore and aft cabin isolated it worked very well in maintaining comfort in the salon through the night…[making] sleeping and hanging out below pleasurable when it would otherwise be oppressive and muggy.

“I am happy, but I think it is important to understand that the trade-off for running on the batteries is that it is not as powerful as a 120V unit that operates like a home air conditioner and needs a generator or shore power to run.”

Archer Power Solutions, 10739 Tucker St., Ste. 243, Beltsville, MD 20705 USA, tel. 202–509–3868.

—D. L.