CH COILS INCORPORATION
DIRECT EXPANSION COILSÂ (DX-COIL)
"Normal Circuiting"
Single circuit evaporator coils are most common with single compressor systems. They consist of only one refrigerant distributor and do not provide for variable loads. This is most commonly used in air-conditioning systems with constant airflow and space/return air temperature.
DIRECT EXPANSION COILS TYPES
FACE SPLIT-DX COIL
"Face Split"- a coil, a horizontal line is drawn across the front of the coil from left to right to divide the coil into the top and bottom halves. Each half is circuited individually resulting in two separate coils in a single casing. Individual compressors are then connected to the top and bottom coils. This method of splitting, however, comes with a significant disadvantage. As the air is directed across the front of the coil when the system is unloaded, air passes over the half of the coil that isn’t in operation resulting in air stratification
INTERTWINED CIRCUITING-DX COIL
"Intertwined Circuiting"
The best method of splitting coils is to intertwine the circuiting. In this method, alternate tubes are included in the first circuit and all the others in the second. So tubes 1, 3, 5 and 7 in the first row are combined with 2, 4, 6 and 8 in the second row to form circuit 1. Ditto for all succeeding rows. All tubes not in circuit 1, are included in circuit 2. The result is an interwoven mat of alternating tubes in the entire coil split into two independent circuits to feed into each compressor. Based on the expected load, each separate circuit needs a separate distributor and expansion valve. The design must also factor in total BTUs, refrigerant types, suction temperature and the number of tubes being fed.
The essential advantage of this method is that even though air passes over the face of the coil, there are always tubes operating if one of the compressors is switched on. The split is always precisely 50:50. This saves you energy and money.
CONDENSER COILS
FOR, PROCESS COOLING EQUIPMENT
