What Is the Difference Between Air Handler And Furnace?

A furnace and an air handler are two heating and cooling devices that are as similar as they are different from each other. Therefore, it makes sense to consider a furnace a type of air handler with the remarkable capacity to warm the air that it moves around the ductwork in a premise to raise the ambient temperature.

You can also consider an air handler a complex heating and cooling device that can move either cool or warm air around the ductwork in the building.

However, an air handler cannot warm the air, as with a furnace. This difference is crucial because it will guide you when you need to choose between an air handler and a furnace for your premises.

We shall look at the differences and similarities between these two heating and cooling devices by considering frequently asked questions about these two common types of heating and cooling devices.

What is a furnace?

A furnace is a complex heating device that generates heat to warm the air and circulates the warm air around the ductwork and through the grates to increase the ambient temperature in the entire house.

Typically, a furnace consists of the following components: a heat exchanger, combustion box, and a thermostat. The combustion box is where the furnace generates the heat used to warm the air in the house.

The heat exchanger helps speed up the process of warming the air near the combustion box of the furnace. Finally, the thermostat helps to automate the way the furnace functions. When the temperature in the home drops to below the standards that you would have set, the thermostat sends a signal to the furnace.

 The furnace then allows the fuel to flow into the combustion box and the burners to be lit. When all the burners are alight, they produce a uniform flame that burns the fuel to produce heat energy. The heat exchanger speeds up the process by which the air is warmed.

The warm air then moves through the grates and ductwork to increase the ambient temperature in the entire premises. When the temperature rises sufficiently, the thermostat signals to the furnace, and the combustion or heat generation process stops.

What is an air handler?

An air handler is a heating and cooling device that moves air around the ductwork and grates in the home to either cool or warm the premises. An air handler consists of a blower fan that forces air through the ductwork. The blower fan is inside a cabinet generally called the air handler.

In addition, the air handler or cabinet contains an indoor coil that determines how the device functions at any time. The air handler depends on the heat sink to generate the heat that warms the air. The function of the air handler is simply to distribute the air and not to generate the warm air.

Your air handler functions in these two modes: heat and air conditioning. During the heat mode, the refrigerant in your air handler traps heat from the outside and channels it indoors. The refrigerant enters the coil with the heat and releases it to heat the coils.

The blower channels the cool air that may be in your house to pass over the coils. The cool air takes up the heat from the coil and circulates it around the house through the ductwork. When you set your air handler in the air conditioning mode, the device takes warm and moist air through the return ducts.

The warm and moist air then travels over the coils and loses its heat to the refrigerant found inside the coils. The blower then pushes the cool and dry air into the house through the supply ducts. Meanwhile, the now-warm refrigerant moves to the heat pump outside the house.

As a result, the refrigerant loses all the heat that it would have accumulated to the outside. It is then channeled back in to take up more heat from the warm and damp air that may be found indoors.

What is the difference between furnace and handler?

Although air handlers and furnaces are both heating and cooling devices that look very similar, they are indeed different. Their similarity lies in their ability to move warm and cool air around the house through the grates and ductwork.

However, the main difference between these two heating and cooling devices is that whereas a furnace generates heat that warms the air, an air handler does not generate any heat.

Instead, an air handle moves either warm or cool air that a different source has warmed. However, a furnace has a combustion chamber and an air exchanger. These two components of a furnace are critical because they warm the air that the furnace’s blower forces through the ductwork.

Pros and cons of furnaces

Before settling on a furnace, you should consider the pros and cons of obtaining and maintaining them for heating your home.


  • They provide a reliable source of heat for the entire home

Heat pumps depend on the warm and damp air to generate heat used to warm the air. This form of heat may not be as reliable as that used by furnaces. Furnaces either burn gas or use electricity to generate heat. Therefore, furnaces provide a highly reliable source of heat.

  • Installing furnaces is much cheaper than other heating sources

You may not have to spend a lot of money to get a furnace up and running. This is in sharp contrast with many other heating devices. For example, you may spend a lot of money purchasing and installing a complete HVAC.


  • Electric and gas furnaces are expensive to operate

Electric and gas furnaces may be costly to run because of the price of electricity and gas. It may be a good idea to get a two-step furnace so that you can control the cost of the fuel by switching to either electricity or gas at any time.

  • Gas furnaces have short lifespans.

You will be forced to replace your gas furnace regularly. This cost of replacing your gas furnace often may add up to a considerable amount of money that exceeds what you would have saved by deliberating avoiding an electric furnace.

  • Gas furnaces pose a security risk when they are running

Gas furnaces may cause fires if one fails to observe the minimum clearance distances when using them. The gas furnaces may also cause carbon monoxide poisoning if one does not use them according to the safety precautions that the manufacturers recommend.

Pros and cons of the air handler

Pros of the air handler

  • Reduced utility bills

Your air handler with either warm or cool the air in your home through the action of the refrigerant. When you set your air handler in the AC mode, the refrigerant cools the air by taking the warmth from it and then dissipating it outside. This helps keep the costs of conditioning the air in your home relatively low.

  • Effective heating and air conditioning performance

Your air handler is an effective device for conditioning the air in the house and generating more heat when the ambient temperature is shallow. The device works effectively to condition the air by removing the warm and damp air and letting in cool and dry airflow through the ductwork and grates of your home.

Cons of an air handler

  • Frequent maintenance

You will have to frequently and constantly maintain your air handler to benefit from its functioning. This may call for additional expenses in checking whether all its components are working perfectly.

  • High replacement costs

An air handler is not as durable as one would expect. Therefore, air handlers need to be replaced as often as possible. This is the case if they develop a technical problem that a technician cannot repair. Therefore, you must be ready to replace your air handler if such a scenario develops.

Is an air handler a furnace?

An air handler is not a furnace, although both are heating and cooling devices that look very similar. An air handler comprises a cabinet with coils and a refrigerant. The cabinet’s work is to move either cool or warm air around the ductwork and the grates of the building.

 The refrigerant can either cool or warm the air that passes through eh coils of the air handler. The refrigerant may then lose the excess heat outside before repeating the process. A furnace is a heating device that generates heat to warm the air and then circulates the air around the ductwork.

 Thus, a furnace differs from an air handler because it has a combustion chamber to burn fossil fuel to generate heat. Electric furnaces utilize electric energy to produce heat energy.

Hydronic air handler vs. furnace

Hydronic air handlers utilize water to transfer heat to the air around the house and eventually increase the ambient temperature. Hydronic air handlers are complex systems with an equally complicated mode of functioning.

However, they are more efficient, reliable, and manageable than forced-air heating systems, including furnaces. Furnaces burn fuel to produce heat.

The heat is transferred to the air and then moved around the ductwork. Hydronic air handlers utilize water to transfer the heat to the air around the house. Thus, using hydronic air handlers is cheaper and more efficient than furnace filters for warming the air in the premises.

What are the differences between furnaces and air handlers?

Here are some of the most common and essential differences between air handlers and furnaces.

  • A furnace generates heat while an air handler does not. This is because an air handler depends on the heat pump that it distributes around the home. A furnace, on the contrary, has a combustion chamber that produces heat. Thus, a furnace distributes the heat it produces while an air handler merely circulates heat from a different source.
  • All air handlers have AC coils and heat pumps. These components are essential for an air handler to work either in the AC or heat mode. However, a furnace does not require any of these components to function.
  • A furnace does not have a cooling function. A furnace is essentially a device that increases the ambient temperature. Furnaces warm the air by either burning gas or utilizing electricity to produce heat. An air handler can either warm or cool the home by moving warm or cool air, respectively.

What are the similarities between furnaces and air handlers?

  • Both air handlers and furnaces are available in different forms. The most common air handlers and furnaces are single-speed and variable-speed ones. Both variable speed air handlers and furnaces allow the users to regulate their operation rate by adjusting the speed. Single-speed air handlers and furnaces do not allow users to change the speed of operation.
  • They have thermostats. The functioning of both air handlers and furnaces begins with the thermostats sending signals to the respective components of the devices. Thus, in both devices, the thermostats play very critical roles.
  • They both come in different blower fan sizes. Your choice of either an air conditioner or a furnace depends on the size of your house. The bigger the house, the higher the airflow requirements, and eventually, the air handler or furnace you need for the building.


Air handlers and furnaces are standard heating and cooling devices with several similarities and differences. Whereas an air handler requires a heat pump to generate the heat that circulates the home, a furnace generates its heat through either fossil fuel combustion or electricity utilization. Nevertheless, both devices require a thermostat to function correctly.

The thermostat sends a signal to the respective components of the devices. In the case of air handlers, they function in either the heat or the AC mode. For furnaces, they can either generate the heat required to raise the ambient temperature or stop if it is already high enough. When choosing any of these devices, you should consider your home’s airflow needs.

The bigger the home, the higher the airflow needs. This means that you will be forced to choose either air handlers or furnaces with high blower capacities.