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THERMOELECTRIC REFRIGERATION

What is it? How does it work?…

WHAT IS THERMOELECTRIC REFRIGERATION?

Refrigeration is the process of pumping heat energy out of an insulated chamber in order to reduce the temperature of the chamber below that of the surrounding air. Thermoelectric refrigeration uses a principle called the "PELTIER" effect to pump heat electronically. The Peltier effect is named after a French scientist who discovered it in 1834.

HOW DOES IT WORK?

In 1834 Jean Peltier noted that when an electrical current is applied across the junction of two dissimilar metals, heat is removed from one of the metals and transferred to the other. This is the basis of thermoelectric refrigeration.

Thermoelectric modules are constructed from a series of tiny metal cubes of dissimilar exotic metals which are physically bonded together and connected electrically. When electrical current passes through the cube junctions, heat is transferred from one metal to the other.

Solid-state thermoelectric modules are capable of transferring large quantities of heat when connected to a heat absorbing device on one side and a heat dissipating device on the other. The Koolatron's internal aluminium cold plate fins absorb heat from the contents, (food and beverages), and the thermoelectric modules transfer it to heat dissipating fins under the control panel. Here, a small fan helps to disperse the heat into the air.

The system is totally environmentally friendly and contains no hazardous gases, nor pipes nor coils and no compressor. The only moving part is the small 12-volt fan.

Thermoelectric modules are too expensive for normal domestic and commercial applications which run only on regular household current. They are ideally suited to recreational applications because they are lightweight, compact, insensitive to motion or tilting, have no moving parts, and can operate directly from 12-volt batteries.

WHY IS IT BETTER THAN AN ICE CHEST?

Food and beverages are kept cold and dry. No space is wasted for ice (unless of course you want ice, in which case we can help to preserve it 3 or 4 times longer than a plain cooler)

ADVANTAGES OF THERMOELECTRIC REFRIGERATION

COMPACT SIZE: Very little space is required by the cooling system. The thermoelectric module is the size of a matchbook.
LIGHTWEIGHT: A 36 qt. capacity unit weighs only 17 lbs.
PORTABLE: Carries with one hand and is unaffected by motion or tilting.
LOWER PRICED: 20% to 40% less expensive than compressor or absorption units.
LOW BATTERY Averages approximately 4.5 amps - less than your cars headlights.

DRAW:
BATTERY PROTECTION: Used in combination with the Koolatron "Battery Saver" you can always be assured of having starting power.
PERFORMANCE: Koolatron coolers maintain "cool" temperatures in ambients up to 90 degrees F.
HEATING OPTION: Koolatrons can be operated in the heating mode for short periods of time. Specialty Heater ONLY versions of our insulated boxes are used by Meals on Wheels, other senior hot meal programs, school hot meal programs and by caterers all across the country.
SAFETY: No open flames, propane, or toxic refrigerants used.
RELIABILITY: Thermoelectrics have a 40 year proven track record in military, aerospace, laboratory, and now consumer applications.
EASY SERVICE: Most parts are easily replaced by the end-user with a screw driver.
LOW The only maintenance required with any Koolatron unit is periodic.
MAINTENANCE: "dusting" and Vacuuming to ensure good heat dissipation.


COMPARISON OF THERMOELECTRIC REFRIGERATION and

OTHER METHODS OF REFRIGERATION

THERMOELECTRIC: Cooling is achieved electronically using the "Peltier" effect - heat is pumped with electrical energy.

COMPRESSOR: Cooling is achieved by vaporising a refrigerant (such as freon) inside the refrigerator - heat is absorbed by the refrigerant through the principle of the "latent heat of vaporisation" and released outside the refrigerator where the vapour is condensed and compressed into a liquid again. Uses mechanical energy.

ABSORPTION Cooling is achieved by vaporising a refrigerant (ammonia gas) inside the refrigerator by "boiling" it out of a water ammonia solution with a heat source (electric or propane). Uses the principle of "latent heat of vaporisation". The vapour is condensed and re-absorbed by the ammonia solution outside the refrigerator. Uses heat energy.

COMPARISON OF THE FEATURES OF ALL THREE SYSTEMS:

COMPACTNESS: Koolatron thermoelectrics are the most compact because of the small size of the cooling components - cooling module / heat sink / cold sink.

WEIGHT: Koolatron units weigh 1/3 to 1/2 as much as the other units because of the lightweight cooling system - no heavy compressor.

PORTABILITY: Koolatrons are the most portable because they are light enough to carry with one hand and are not affected by motion or tilting. Compressor models are quite heavy and the absorption models must be kept level within 2 - 3 degrees.

PRICE: Koolatron coolers cost 20% - 40% less than the equivalent sized compressor or absorption units available for recreational use.

BATTERY DRAIN: Koolatron coolers have a maximum current drain on 12 volts of 4.5 amps. Compressor portables draw slightly more current when running but may average slightly less depending on thermostatic control settings. Absorption portables draw 6.5 to 7.5 amps when running and may average about 5 amps draw.

BATTERY PROTECTION: Consider the "Battery Saver" option as discussed in the previous section.

COOLING PERFORMANCE: Compressor systems are potentially the most efficient in hot weather. Some models will perform as a portable freezer and will refrigerate in ambient temperatures of up to 110 degrees F.
Koolatron units will refrigerate in sustained ambient temperatures of up to 95 degrees F. If they are kept full, they will refrigerate satisfactorily even if peak daytime temperatures reach 110 degrees F because the contents temperature will lag behind the ambient. The food will be just starting to warm up when the air cools off in the evening which will bring the food temperature back down to normal.
Absorption type refrigerators provide almost the same cooling performance as Koolatron portables but are less efficient at high ambients.

FREEZING ICE CUBES:
Compressor systems will usually make a quantity of small ice cubes except in very hot weather.
Gas absorption systems can do the same except in hot weather.
Koolatron thermoelectric units do not make ice cubes but can preserve them in a plastic container for 2 - 3 days which is often adequate for most applications.

SAFETY: Koolatron systems are completely safe because they use no gases or open flames and run on just 12 volts. Compressor systems can leak freon which can be extremely dangerous especially if heated. Absorption systems may use propane which can be extremely dangerous in the event of a leak.

RELIABILITY: Koolatrons thermoelectric modules do not wear out or deteriorate with use. They have been used for military and aerospace applications for years because of their reliability and other unique features. Compressors and their motors are both subject to wear and freon-filled coils are subject to leakage and costly repairs. Absorption units are somewhat temperamental and may require expert servicing from time to time, especially if jarred when travelling.

EASE OF SERVICING AND MAINTENANCE: Koolatron units have only one moving part, a small fan (and 12 volt motor) which can easily be replaced with only a screw driver. Most parts are easily replaced by the end-user. Compressor and absorption units both require trained (expensive) mechanics and special service equipment to service them.