48v DC-Direct Marine Solar Water Chiller for Yachts

Solar-powered air-conditioning or heating on a Yacht without a generator or inverter!  In the past, comfort required staying tethered to shore power on the dock in a marina. But you purchased the boat to explore and enjoy peaceful, even exotic, remote anchorages. Then you discovered that meant running a large, noisy, diesel-hungry expensive, high-maintenance generator 24/7 while cruising and at anchor, completely polluting the sounds of peaceful anchorage.

Imagine navigating by day in a comfortably air-conditioned/heated helm while recharging batteries and desalinating enough water for the evening. (See our 48v DC Direct Water-Maker.) After dropping anchor for the evening, you redirect that energy to cool down the salon and galley to a perfect temperature while preparing dinner, and enjoying cocktails with a movie without the background drum of a generator running. After the movie, you open the salon doors to let the evening air swirl through the salon while retiring to your quiet bug-free air-conditioned cabin for a restful night’s sleep.

How is this Dream Possible?

A marine water chiller functions like an open-loop geothermal heat exchanger.  Read Why is DC-Direct better?

1. The 48v DC 24,000 BTU Titanium Water Chiller is installed in the Yacht’s engine room or bilge storage area. The chiller transfers heat from the internal water-glycol system to the exterior raw water for cooling or reversed for heating. A water-to-water heat exchanger is essentially two water pipes, isolated from each other,  transferring heat through a membrane without mixing, and circulation pumps. It’s internally closed-loop, so not affected by the hot, humid air of the engine room or bilge.
2. Each space on your yacht (cabins, salon, indoor helm) that needs cooling or heating receives its own appropriately sized, very quiet air handler (essentially a radiator, fan, and thermostat/humidistat). This naturally zoned system makes it possible to only cool or heat one or more occupied cabins at night or only the salon or helm by day and not the entire boat!
3. A single insulated pipe originating at the water chiller, or an optional Thermal Energy Storage Buffer Tank is fed by a circulation pump and loops around the boat connecting each air handler in series and then terminating at the water chiller.
4. When the thermostat/humidistat of any of the air handlers turns on,  it turns on the circulation pump

Features

• Simplicity = Low maintenance! Turns off when the chilled water temperature difference between inlet & outlet reaches 41℉
• Titanium Heat Exchanger – much longer life over nibrol especially in saltwater environments
• The compact size and option of multiple units in parallel make installation in an already cramped engine room or bilge storage space easier.
• Infinitely Variable from 3,000 to 24,000 BTUs – internally contains two 12,000 BTU stages, each automatically and independently adjusting to available power and demand. Chiller operates on 1 compressor if the demand is less than 12,000BTU
• Plumb 2, 3, 4 or more in parallel for larger vessels that require 48,000 BTUs, 73,000 BTUs, or  96,000 BTUs or more.
• The noise and heat generated by the compressors is removed from the living space, improving efficiency and blissful silence.
• Only 2 Brushless 48v DC circulation pumps are smaller and naturally variable speed, with less internal resistance so more efficient, and up to 10x longer lasting than brushed AC pumps.

Quality Components

• Titanium Condensing Coils
• Stainless Steel Plate-Type Heat Exchanger Evaporator
• Two 12,000 BTU 48v DC Rotary Compressors
• Thermal Expansion Valve
• R134a Refrigerant
• DC Controls – High / low-pressure switches, gauges, safety valves

Q&A

What are Inlet water temperature limits for Cooling and Heating?

When Cooling, inlet water temperature must be >68℉ (20°C). When heating, inlet water temp must be above freezing or >34℉ (2°C).  The minimum storage temperature for the closed loop circulation between air handlers and chiller is based on glycol/water mix used.

How to Heat when temperatures drop below freezing?

For heating below freezing, the exterior raw water circulation pump is left off. Instead a water heater (electric, diesel, LPG, or natural gas boiler) is used in the interior distribution loop. 

With this system, can I use waste heat off the engines or generator to heat the boat?

YES, you can use waste heat off your main propulsion or generator engines by adding a passive heat exchanger between the engine coolant and the interior distribution loop. With some creative plumbing (bypass valves), a portion of the propulsion engine coolant could be passed through the raw water intake of the chiller (unsupported, could void warranty).