The refrigeration unit has no moving parts, making it vibration free and requiring little maintenance. It is also completely silent and freon-free. Absorption cooling technology was invented more than 80 years ago and its many strengths have since then been applied to new areas: hotel refrigerators, wine cellar and portable boxes. Dometic is today the world’s leading provider of absorption refrigerators.
ABSORPTION COOLING SYSTEM
In an absorption refrigerator system, ammonia is liquefied in the finned condenser coil at the top rear of the refrigerator.
The liquid ammonia then flows into the evaporator (inside the freezer section) and is exposed to a circulating flow of hydrogen gas, which causes the ammonia to evaporate, creating a cold condition in the freezer.
When starting this refrigerator for the very first time, the cooling cycle may require up to four hours of running time before the cooling unit is fully operational.
The tubing in the evaporator section is specifically sloped to provide a continuous movement of liquid ammonia, flowing downward by gravity through this section.
Sodium chromate is used for corrosion protection (less than 2 weight % of the coolant).
LEVELING THE REFRIGERATOR
Leveling is one of the requirements for proper operation with absorption refrigerators. to ensure proper leveling the vehicle needs to be leveled only so it is comfortable to live in (no noticeable sloping of floor or walls).
Any time the vehicle is parked for several hours with the refrigerator operating, the vehicle should be leveled to prevent this loss of cooling.
If the refrigerator is operated when it is not level and the vehicle is not moving, liquid ammonia will accumulate in sections of the evaporator tubing. This will slow the circulation
of hydrogen and ammonia gas, or in severe cases, completely block it, resulting in a loss of cooling.
When the vehicle is moving, the leveling is not critical, as the rolling and pitching movement of the vehicle will pass to either side of level, keeping the liquid ammonia from accumulating in the evaporator tubing.
Cool the refrigerator before placing any food inside.
Never put hot food or drinks into the refrigerator – cool them first.
The food storage compartment is completely closed and unventilated, which is necessary to maintain the required low temperature for food storage. Consequently, foods having a strong odor or those that absorb odors easily should be covered.
Vegetables, salads etc. should be covered to retain their crispness.
The coldest positions in the refrigerator are under the cooling fins and at the bottom of the refrigerator.
The warmer areas are on the upper door shelves. This should be considered when placing different types of food in the refrigerator.
Arrange all food in the unit to allow for free air circulation.
Do not overpack because a stuffed refrigerator must work harder and will have higher cabinet temperatures.
Do not leave the unit’s door open any longer than necessary. This will reduce frost formation and increase the efficiency of the refrigerator.