Two main types of “portable refrigerators” exist: the thermoelectrics (also known as peltier junction units) and the compressor systems.

Thermoelectric Units

Thermoelectric units — such as Igloo® and Coleman units found at retail or sporting goods stores — are coolers, not refrigerators. Thermoelectric units offer two main benefits: low price and small size. Disadvantages are that they can cool only to about 30-35 degrees below ambient temperature, they draw considerable amounts of current, and they cannot freeze their contents. In 90-degree surroundings, for example, the inside of a thermoelectric cooler is about 60 degrees — certainly not cool enough for most uses. Thermoelectrics offer poor performance in extreme heat, eventually becoming nearly useless. Worse, because these units run continuously and draw up to 10-amps from a vehicle's battery, they can prevent the vehicle from starting.

Compressor Units

A compressor system like the one in FridgeFreeze vaccine refrigerator/freezers is built using similar equipment to your home refrigerator/freezer. This type of system consumes less power and can refrigerate or freeze in warmer ambient temperature. These units perform better and are more efficient than thermoelectrics.

FridgeFreeze Compressor Units

The FridgeFreeze vaccine refrigerator/freezer is the most efficient portable 12/24 and 110-volt vaccine refrigerator/freezer made. The 15-liter, 20-liter, 35-liter, 45-liter and 60-liter models draw between 2.3 and 3.8 amps when the compressor is cycled on. The 100-liter model draws between 4.6 and 7.6-amps. All FridgeFreeze vaccine refrigerator/freezer models are so well insulated that the compressor is running only about 10 to 15 minutes per hour on average to maintain internal temperature.