One of the most familiar types of air conditioning and heating is a forced air central system. It relies on a main source to heat and cool air, which is then delivered to rooms through ductwork and vents in the floor, ceiling or walls.

For an easy understanding of central air conditioning and heating, and HVAC in general, here are three basic points:

  • Air is cooled through the refrigeration process, which at a minimum, requires refrigerant, condenser and evaporator coils and a compressor.
  • Sources of heat include electric heaters, and fuel burning or electric furnaces and boilers.
  • Central heating and cooling systems combine air conditioning and heating components, which are each separate systems. The only exception is an air conditioner heat pump, which uses the same components that cool – compressor, refrigerant plus evaporator and condenser coils -- to deliver heat.

There are several different ways that central heating and cooling systems can be configured:

Split systems

An air conditioner split system consists of an indoor unit and an outdoor unit. The indoor unit, also called an air handler, contains the blower motor and evaporator coil. The blower propels air over the evaporator coil which cools the air. After passing over the evaporator coils, the work of the blower continues and cooled air is forced through the ducts and delivered to each room.Outdoor units are located on the building exterior and hold the compressor along with the condenser coil.

In homes with furnaces, incorporating cooling into the system requires just adding a compatible evaporator coil. This is possible because furnaces contain blowers. The blower in the furnace pushes unheated room temperature air over the evaporator coil so the refrigeration cycle can occur. The evaporator coil usually sits on top of the furnace. Please visit our selection of condensers and coils if you have a furnace and would like to add or upgrade your central air conditioning.

Another heat option is to join an electric heater with the ac system and use the air handler’s blower to circulate the heated air.

Whether you are adding heat to existing central air conditioning or adding central ac to your heating, all of the components must be compatible. Complete split system central air conditioning and heating systems can also be purchased together, preconfigured from the manufacturer. Our Learning Center provides an overview of air furnace matched systems, and we offer a large selection of gas furnace plus air conditioning systems.

Heat pump split system

Heat pumps cool the air using the refrigeration cycle and provide heat by reversing the refrigeration cycle. Heat pumps are known for using very little electricity. They include an indoor unit and outdoor unit. The compressor is located in the outdoor unit. What makes heat pumps unique is that both coils can function as a condenser or evaporator. Once the refrigerant direction is reversed with a “flip of a switch,” the coils also reverse their functions. Review Heat & Cool's selection of heat pump central systems to see which one is right for your home.

Packaged units

Packaged Units offer an all-inclusive heating and cooling solution and they are stored outside. Small commercial buildings usually place these units on the roof. Residences usually locate them outside in a crawl space or at ground level.

There are four packaged unit configurations:

  • Gas heat combined with air conditioning provides powerful gas heat for severe climate zones and standard 24V air conditioning. These are often referred to as Gas/Electric Packaged Units.
  • Another configuration is Heat Pump Packaged Units. They use reverse cycle technology to provide heat and are usually available with field-installed emergency/auxiliary heat strips.
  • Dual-Fuel Packaged Units are hybrids that provide energy-efficient heating and cooling through heat pump technology and when the winter temperature is too extreme for the heat pump, the gas furnace automatically kicks in.
  • Air conditioner packaged units are available as well. They only provide cooled air.

Central Air Conditioning and Heating Sizing Guide:

Central Air Conditioning and Heating Sizing Guide