How to install the air-cooled condensing unit: Simple instructions -F.Sanzo-
The installation of air-cooled condensing unit, although simple, requires some precautions.
The condensing unit requires correct positioning for a good ventilation which avoids the recirculation of air which can cause condensation problems. Furthermore, the correct sizing of the liquid and suction pipes is important for the proper functioning of the system.
It is important to avoid the backflow of lubricant and liquid refrigerant to
the compressor when the condensing unit stops.
It is necessary to provide suitable siphons at the base of each vertical section with an upward direction of the flow; if the discharge line is of high vertical development which connects the compressor to the remote condenser, that is installed at a higher altitude, it must be equipped with an adequate number of siphons.
Even the suction line, the pipe that connects the evaporator to the compressor suction, must meet certain requirements such as:
• favor the return of oil to the compressors especially to those equipped with a capacity control system, therefore when the system works at reduced power
• prevent the return of oil and refrigerant to the compressor when it is off, adapting the suction line and installing suitable siphons that prevent it from returning.
• ensure that the speed of the refrigerant is such as to guarantee the entrainment of the lubricant without excessive pressure drops
If the suction line is not isolated, it absorbs a considerable amount of heat along its path from the evaporator to the compressor. All this is a loss of system efficiency and is a greater thermal stress on the compressor due to the higher temperature of the refrigerant sucked in.
In order to minimize these negative phenomena, it is essential to provide thermal insulation of the suction line, coating it with insulated pipes of adequate thickness.
It is also necessary to check the compressor oil level since it is necessary to check the entrainment with the refrigerant in the other parts of the circuit. Then you should check the compressor oil sight glass, when the machine is turned off, to make sure the level is regular. If necessary, the additional charge must be carried out as a precaution in different phases and at a distance of a few hours after starting.
A further check is the correct functioning of the expansion valve in order to obtain the maximum possible efficiency. It is important to check the correct position of the bulb and the certainty that the liquid refrigerant reaches the expansion valve completely.