A ColdMachine converts an insulated, built-in icebox to a thermostat-controlled refrigerator/freezer.
This CU-100 air-cooled ColdMachine condenser provides up to 15 cu ft of refrigeration capacity. It needs to be paired with one of the four Adler Barbour VD-Series evaporators, or a VD-160 cold plate - which are installed inside the icebox; see Related Products, below.
Note that a complete refrigeration installation requires the purchase of both a condenser unit and an evaporator (or cold plate).
ColdMachines are specifically designed for marine use to handle hot and humid conditions, erratic or low voltage, and continuous use.
ColdMachine kits now come with self-sealing quick-connect fittings for easy attachment. Unlike the old "one-shot" connections, quick-connect fittings can be disconnected and reconnected whenever necessary without loss of refrigerant - a huge advantage.
If you are upgrading an existing system, Quick-Connect Adapters are available to join older "one-shot" components to newer "quick-connect" counterparts (professional installation is required).
Note that compared to this air-cooled only CU-100 ColdMachine, the air or water cooled CU-200 Super ColdMachine has default air cooling from the factory, but includes a supplemental water-cooling function to take advantage of the greater cooling capacity of water compared to air. See Related Products, below.
• A complete system includes a condensing unit and an evaporator (or a VD-160 cold plate). Condensers and evaporators are sold separately - buy one of each
• Condensers and evaporators are both pre-charged with refrigerant and ready to install
• Reliable Danforth/Seacop BD50F compressor; current draw is typically 3-5 amps per hour for a 6 cu ft insulated refrigerator box; a 300 Ah or larger battery bank is recommended
• Shrouded forced-air condenser coils
• Corrosion resistant stainless steel base
• Modular phone-jack connection for thermostat
• Built-in troubleshooting diagnostics
• Evaporators and cold plates include a thermostat kit and 15 ft copper tubing (12.5 ft for cold plate) to reach the condenser unit
• Optional Vent Kits allow you to exhaust hot air, or source cooler air, to or from a remote location; see Related Products
• BTU rating: 650/hr maximum at +25°F evaporator temp
• Evaporator capacities assume refrigerator with 3" of polyurethane insulation and 40% run time; or freezer with 4" of insulation and 50% run time
• Warranty: 1-year labor; 2-years parts
• Made in USA
Note — The ColdMachine CU-100 condenser unit should only be used with VD Series 3-digit evaporators - for example: VD-152. It is not designed to be used with VD-xx (2-digit) evaporators.
Heavy on the technical side...
A refrigerator or freezer works by using a heat pump to transfer heat from inside a closed, insulated compartment (icebox) to the outside of that compartment.
ColdMachine modular refrigerator/freezer systems utilize "vapor-compression" refrigeration and consist of an external condensing unit (which is comprised of a compressor, a condenser [coils], and a thermostat) and an evaporator plate or cold plate located inside a customer supplied insulated icebox.
In vapor-compression refrigeration, the refrigerant undergoes liquid/gas phase changes — the liquid refrigerant evaporates into a gas in the evaporator plate inside the refrigerator (absorbing heat), and then is changed back into a liquid in the condensing coils outside the refrigerator (releasing the heat). The cycle keeps repeating and... Voila! A heat pump!
Again, in somewhat more detail...
Liquid refrigerant from the condensing unit flows to the thin aluminum evaporator plate inside the icebox where it is allowed to rapidly expand and evaporate into a gas. Even though the rapid expansion is a passive event, heat is still required to make the change from liquid to gas happen. This "heat of vaporization", is supplied by the "warm" air inside the icebox. Inside the large surface area evaporator plate, the cold vaporized refrigerant absorbs this heat from the air in the icebox as it flows through the coiled tubing in the evaporator — leaving the air colder.
The warm vaporized (gaseous) refrigerant then flows to the compressor, where it is compressed into a high pressure, super-heated gas, which then flows through tubes surrounded by high surface area fins on the outside of the icebox. (These are the familiar black coiled tubes on the back of the refrigerator in your kitchen.)
In the condensing tubes (or coil) the heat from the hot refirgerant is transferred to the cooler room air, cooling the gaseous refrigerant, allowing it to condense back into a liquid....which then flows back to the evaporator inside the icebox.
Instead of a thin, fragile aluminum evaporator plate, another option for cooling the icebox is to use a "cold plate", or "holding plate".
A cold plate is a sturdy, sealed, metal enclosure which contains the evaporator coils immersed in a solution which feezes and melts at just about the same temperature as the inside of your icebox. When the compressor is running, refrigerant flows into the cold plate inside the icebox. This time,
Unlike an evaporator, which only cools when the compressor is running, a holding plate has the ability to "store cold" by virtue of the frozen fluid it contains, This means it continues to cool the contents of the icebox even when the compressor is not running. It can do this because as the frozen solution inside the cold plate slowly melts, it absorbs heat from the food in the icebox.
Refrigeration systems using holding plates are expensive, but are extremely popular - especially among long-distance cruisers.
This is because they only use about half the amp hours of a typical icebox conversion system, and the system might require only a few hours of run time each day - conserving both fuel and sanity.