Need System Advice or a Free Quote?
We’ve Got HVAC Pros Ready to Help!
Quote Form - Top of Page

Split Air Conditioning Systems

Split air conditioning systems are a common type of HVAC system throughout the country, in all climate zones.  In this guide we will provide an overview of how they work.  If you own one perhaps you’ll have a better understanding of their operation that will enable you to confidently speak with an HVAC contractor about repairs your system may need, or about the possibility of replacing the system.  And if you are considering the installation of a split air conditioning system, this guide may help you decide if this type of system makes the most sense for your home.

The Components of a Split Air Conditioning System

To begin with, a split system means that the components are located in 2 separate areas.  In a split air conditioning system, the condensing unit is located outside the home, usually on the ground near the foundation. The condensing unit is the heart of the air conditioning system and is often simply called the “air conditioner.”  In most climates, a gas furnace makes up the second half of the split system.  It is typically located in the basement of the home, or perhaps the attic or a first-floor utility closet.  In very warm climates, or in homes that use an alternate form of heating such as a wood stove, the furnace may be replaced by an air handler that circulates air through the home but does not produce heat.

The furnace or air handler also contains the indoor coil, also known as the evaporator coil, which is an essential part of the cooling system.  The third important component of a split air conditioner system is the home’s ductwork which must be sized correctly to match the capacity of the blower in the furnace or air handler.  Now let’s look at how this system heats and cools your home.

Heating your Home

Let’s start with heating.  The gas furnace starts up when the temperature in the home drops below the setting on the thermostat. The first sound you’ll hear is the draft fan blowing air up through the vent or flue to determine that the passageway is open.  Then a hot surface igniter begins to heat up.  The gas valve opens and gas enters the burner.  It is ignited and begins to create heat.  All of this happens in a sealed combustion chamber so that the heat stays in the system and no carbon monoxide or other combustion gases escape into the house.

Once the burner fires, the blower motor starts and the blower fan begins drawing cold air into the system through the return ducts.  The heated air passes, containing the combustion gases, passes through a heavy-gauge metal part known as the heat exchanger.  It radiates heat which warms the air around it.  The heated air is circulated through the home via the ductwork, pushed by the blower.  This heating and circulation of air continues until the air temperature around the thermostat reaches the desired temperature.  The combustion gases leave the home via the flue once they have passed through the heat exchanger.  High-efficiency gas furnaces use a secondary heat exchanger to effectively dissipate more heat before it can be lost up the chimney.

Cooling your Home

Here is how a split air conditioning system cools your home.  The condensing unit has a compressor that pumps refrigerant into the home via an insulated copper lineset.  The liquid refrigerant enters the evaporator coil in the furnace or air handler where it quickly evaporates into a gas.  As it expands into a gas, it rapidly captures heat from the home, effectively cooling the air around the coil.  That cooled air is then distributed through the house via the ductwork and blower, while warm air is being drawn into the system.

The refrigerant is now a gas.  It carries the heat out of the house via another copper line connected to the condensing coil.  There, it condenses back into a liquid, shedding heat in the process.  That heat dissipates quickly through the condensing coil, which looks very much like a radiator.  The released heat is dispersed by the condensing unit fan.  This cycle continues until enough heat is removed from the home to lower the temperature to the desired level.

Where to Buy a Split Air Conditioning System

Split air conditioning systems are popular because they are affordable and effective.  They are also quite efficient, too.  High-efficiency systems cost more, but because they use electricity and gas more sparingly, they are also cheaper to operate.  When you are considering the purchase of a split system, you will find wholesale HVAC prices at online locations like eBay.  Large supply companies offer their inventories there at very competitive prices.  Take a look at split air conditioning systems reviews to narrow you choices to the one that makes most sense for your home and budget.


Split air conditioning systems make good sense for most homes.  However, the reliability, efficiency and durability of the system is often only as good as the installation.  The components must be compatible, and they must be properly installed.  It always makes sense to have a qualified contractor help you select the right system for your home and then install it, making sure it is adjusted correctly and tested.  When properly installed, a quality split system will deliver 15 to 20 years of reliable service.

We hope this overview of the split air conditioning system helps you make an informed decision as you consider your current and future HVAC needs.

Need System Advice or a Free Quote?
We’ve Got HVAC Pros Ready to Help!
Quote Form - Top of Page

Leave a Reply

Your email address will not be published. Required fields are marked *