Air conditioning systems are basically divided into two main groups:
Direct Expansion
Indirect expansion
Direct expansion equipment is those that operate with the direct use of a refrigerant gas in order to cause the air to be conditioned to be cooled. These systems are represented by the conventional "window", "splits", "VRF" and small central air conditioners.
For large systems or systems requiring some kind of strict temperature, humidity and filtering control, such as "shopping malls", "data centers", hotels, hospitals and large commercial buildings, indirect expansion systems are usually used , Also called cold water systems. In cold water systems, the cooling equipment is installed in an area of the building, called the Cold Water Central.
In the Central de Água Gelada incorporates equipment called "chillers" that produce the cooling of the water. The chilled water produced in the chillers is pumped and distributed through a network of pipes to all areas that will be conditioned.
As these pipes carry chilled water they are insulated thermally. In the chilled water system, air cooling is performed by other equipment called fan coils, which are composed of a fan that carries the air and a coil Which circulates the ice water.
The fan-coils can be large, installed in engine rooms and with the distribution of the air by ducts or, even, they can be small apparatuses ("fancoletes").
The "fancoletes" have the same appearance as "split" equipment. The chilled water system has the following advantages over direct expansion equipment:
Possibility of installation of a power less than the sum of the maximums due to the diversification of use between the several areas of a building;
Features lower power consumption when using high efficiency chillers;
Allows the installation of thermoaccumulation systems;
Every cooling system is located in a single area, facilitating the operation and maintenance of the system;
