Heating Systems

• Heating System
  
  A heating system produces and distributes warm air throughout a building for the purposes of temperature control. Heating systems run off gas or oil and can produce both hot air and hot water. The central component of a heating system is a gas- or oil-fired furnace. The furnace contains an internal combustion mechanism that produces hot air. A separate component of the furnace contains water and is attached to the building's main water line; the furnace heats this water, which is then stored in an insulated hot water tank and is available for use. The hot air is then piped through the house and expelled through a radiator or baseboard vents. Some heating systems use steam radiators to heat the house. Once the room is warm, excess steam is condensed back into water and returned to the furnace through a cold water return pipe.
  
  

Air Conditioning Systems

• Air Conditioning System
  
  An air conditioning system produces and distributes cool air throughout a building for the purposes of temperature control. An air conditioning system runs off of an electric motor attached to a compressor, which is a mechanical device that helps turn refrigerant chemicals (such as Freon) into a cool gas. A fan is also attached to the electric motor next to the compressor. The fan sucks in warm air from the outside, which is then funneled into the compressor via a tube near the air intake area. The compressor contains a separate compartment that houses the refrigerant; as the compressor fills with warm air, it evaporates the refrigerant into a cool gas, which cools the warm air. The air conditioning unit also has a condenser, which is located near the fan. One end of an exit tube must be attached to the compressor with the other end attached at the rear of the fan. The exit tube propels the cooled air from the compressor to the fan, which blows it into the condenser. The condenser compresses the cool gas, which is piped into the house via a coolant line. The cool gas enters an evaporator unit, which evaporates the gas into cool air. The cool air is then blown into the house through a blower, which also sucks in air to improve circulation. The air passes through a filter, which removes debris, and is then blown out of the air conditioning unit by the fan.
  
  

Integrated HVAC Systems

• Diagram of Residential HVAC System
  
  In most buildings, heating and air conditioning systems are part of an integrated heating, ventilating, and air conditioning (HVAC) system, which uses pipes and ductwork to regulate temperatures. HVAC systems are often hooked to a central thermostat, which automatically engages either heat or air conditioning should a building's temperature change from a specified level.