Heating, ventilation and air conditioning (HVAC) in the home has a few principal functions. These principles include controlling the temperature, the humidity, and maintaining the atmosphere quality. Heating and cooling systems are classified into two groups: Central and local systems.
Central System
The central system is the most standard method for controlling the temperature in the home. It produces warm or cool air in one central area and then distributes it throughout the house. They may be either radiant or forced air. It is most commonly a central AC unit, as well. Some examples of central HVAC schemes include heat pumps, gas and oil furnaces, evaporator coils, and air conditioners.
Heating Using Central System
Heating units provide welcomed warmth to the home especially in cold climates. They are either radiant or forced air heating systems.
Radiant systems work by transferring heat from heated water or steam that is circulated through an arrangement of radiators or exchangers. The radiators transfer heat to the area or room by convection and not radiation.
Forced air central heating operates by heating an exchanger (usually a furnace) either by hot water, gas, electricity or oil. Air is forced to pass over or through the exchanger that warms the atmosphere. The hot ventilation circulates through sheet metal ducts which run into each room or area by registered vents. Read entire article.