Refrigeration systems consist of four major components, these are the compressor, condenser, expansion device (usually a TX valve) and evaporator. The condenser is a heat exchanger used to transfer heat from the refrigerant to the ambient air or water. Air cooled condensers are constructed of a fin and tube or micro-channel coil and fan/s which are housed in a cabinet. Water cooled condensers are constructed as tube in tube or shell and tube designs. Stand alone condensers are often called remote condensers as they are positioned remotely from the system they serve.
Actrol have a variety of remote condensers available to suit many different commercial and light industrial refrigeration and air conditioning applications. Typical applications include receiver units and reticulated rack compressor systems in hotels, supermarkets, shopping centres, office buildings, manufacturers and food processors, farms, pubs, clubs, boats.
Actrol condensers can be put into four categories:
Air Cooled Fin and Tube Condensers
This is the most popular style of condenser and is constructed with one or more fin and tube heat exchanger. Coil or coils with induced draft fans to move plenty of air through the coil to improve efficiency.
The tubes are usually made of copper and the fins of aluminium. Protective fin coatings are often used to protect the aluminium from corrosion. The fans can be speed controlled or simply cycled on and off to enable the condensing temperature to be controlled. Alternating current (AC) fans are generally used, however brushless direct current (EC) electronically commutated fans have been introduced to some ranges as they are more energy efficient.
Air Cooled Micro Channel Condensers
Micro-channel condensers are now appearing in the market. These are manufactured from blocks of aluminium and have very small (micro) channels in which the refrigerant flows. The advantages of micro-channel condensers are a reduced refrigerant charge and the aluminium can be recycled at end of life. The disadvantages of micro-channel are its extremely small fin spacing which is prone to clog with airborne dust thereby reducing efficiency. The protective coatings are still being researched to reduce corrosion.
Fresh Water Cooled Condensers
Water cooled condensers transfer heat from the warm refrigerant to the cooler water. Water cooled condensers are offered as tube in tube and as shell and tube. The major difference is shell and tube designs can be mechanically cleaned on the water side which is an advantage especially when an open water circuit is used. An open water loop is open to the atmosphere and the airborne pollutants whereas in a closed loop the water is enclosed and does not come in contact with the atmosphere. The water loop consists of a pump, a cooling tower or closed circuit water to air heat exchanger. The water should be treated to manage the acidity and other chemical levels and if a cooling tower is used legislation requires the water be treated for Legionella to protect against outbreaks of Legionnaires Disease.
Sea Water Cooled Condensers
Sea water condensers are usually used on fishing boats, ferries, ocean liners and some pleasure craft. The water is simply drawn from the ocean, pumped through the condenser and back into the ocean. Sea water condensers are usually a shell and tube design as mechanical cleaning is required to reduce the affects of algae and general fouling.