Correct Amount of Refrigerant


This review is intended to display many actual refrigerant system condition reports and suggested corrective action regarding Too Much or Not Enough Refrigerant. Also included in this summary are variations of  methods of obtaining refrigerant charge in different manufacturer's systems.


 Too Much Refrigerant


Not enough Refrigerant


Servicing, Leak testing and Dehydration Vacuuming



Refrigerant volume must be exact if optimum performance is to be expected from a small 12/24 volt system incorporating a capillary tube refrigerant expansion device.  There are nearly 100 different configurations of these 1/8 horse power or smaller 12/24 volt units. A few of Danfoss powered systems use Thermo Expansion Valves (TEVs) or Constant Pressure Valves. Refrigerant volumes required for each Danfoss BD system are determined by the system manufacturer. Because capillary tube systems are so small refrigerant volume is defined by weight from 40grams to 150 grams. Most current manufacturers selling icebox conversion units sell separate sizes of evaporators for one or more condensing units.  Each of their units contain a different amount of refrigerant. Example an Adler Barbour CU 100 is shipped with 80 grams of refrigerant and their VD150 evaporator 30 grams of refrigerant, change to another evaporator it will have a different refrigerant charge.  An error more than 15 grams will affect performance.  To compare weight of grams to ounces, one ounce equals 28.3495231 grams. This means an Adler Barbour CU 100 with a VD150 evaporator contains only 3.88 ounces of refrigerant when it contains volume of refrigerant recommended in Adler Barbour’s manual.


Most all home refrigerators are designed for relative stable operating indoor temperatures so refrigerant volume drift is not much of a problem. Mobile refrigeration where condenser cooling medium’s temperature changes daily system performance will change do to refrigerant volume/ pressure drift.


Important facts to remember:  If 12/24 volt BD compressor will not run it is not because it is low on refrigerant. Danfoss BD compressor will still run with no refrigerant in system. If compressor will not run it is because its electronic module senses a voltage spike or condenser fan circuit is overloaded or compressor is drawing too much current