Parts of the HVAC System You Should Know

Your HVAC system is responsible for cooling your home during summer, warming it up during winter, and regulating humidity levels for indoor comfort. It is undoubtedly one of the most important systems installed within a house.

But does the average homeowner know how the system functions, or even the components that make it up?

To many homeowners, an HVAC system is just another device that makes indoor life comfortable. However, today we’ll take a deeper look at what the system entails and ask questions, such as– what are the parts of an HVAC system? And, what is the function of each part?

But before that, let’s first look at the different types of HVAC systems that exist in the market.

Generally, there are 4 main types of HVAC units available. Each one has its benefits and drawbacks. For this reason, when choosing an HVAC system for your home, ensure you’ve evaluated your needs and compared it to each type’s features to see what system best suits you.

Types of HVAC systems

These systems include:

1. Heating and cooling split systems

As its name might suggest, this system is made up of two units: the outdoor unit, which cools the house, and an indoor unit that heats the house.

The cooling unit comprises a compressor, fan blower, refrigerant, and coils. On the other hand, the indoor one consists of a gas heater that warms your house. This is the standard HVAC system that’s used across homes in North America, and represents traditional building senses. Many old homes have been constructed with these systems.

2. Hybrid split systems

A hybrid split system is a combination of two different types of HVAC systems, usually a ducted system and a duct-free system. This means that it uses traditional ducts but still offers the benefits of a ductless unit.

These systems are known to conserve energy, which subsequently leads to lower energy bills. Also, they can easily switch from gas power to electric one, which is more efficient and with less noise.

3. Duct free

A duct-free HVAC system, also known as a mini-split system, is composed of an outdoor unit and one or more indoor units.

The outdoor unit contains the compressor and condenser coils, while the smaller indoor units hold the evaporator coils. The indoor units deliver warm or cool air to each room.

4. Packaged heating and Air

A packaged heating and air conditioning system is a single unit that contains all the parts of an HVAC system. The system is usually installed on the roof or ground level outside the house.

The most common type of packaged HVAC system is the heat pump, which can be used to both heat and cool. 

What are the parts of an HVAC system?

1. Combustion Chambers

This is usually the source of heat for a furnace. The combustion chamber is where the fuel is burned to create heat.

Here, oxygen is added to the fuel to create a flame. This flame is then used to heat up the air that is sent through the ductwork.

But, before the heat gets to your indoor air, it first passes through the heat exchanger, where the transfer takes place. 

2. Thermostat

A thermostat is the technology behind HVAC operations. It’s like a thermometer that connects to the system’s heating and cooling sections. This allows it to determine the best time for the heater or air conditioner to come on.

Many types of models are available today that automatically change the temperature based on the schedule you set. And for zoning purposes, you can install multiple thermostats as well.

3. Heat Exchanger

The heat exchanger is a set of coils or tubes that are used to transfer heat from one fluid to another. In an HVAC system, the heat exchanger is used to transfer heat from the combustion chamber to the air that is being sent through the ductwork.

Generally, a heat exchanger will be located within the furnace/heater, acting as the medium for heat transfer between the chamber and your indoor air. Essentially, hot combustion gases are usually forced inside the heat exchanger while cold indoor air is blown over it.

The combustion gases inside the heat exchanger heat the air blowing over it, which is then blown through the ducts to the house.

A heat exchanger also plays another crucial role during the process. It helps to separate toxic gases from the combustion process from the air going inside your house. This means that any problem with the heat exchanger can easily lead to grave consequences like carbon monoxide leaks.

4. Condenser Coil 

A condenser is simply the cooling section of the HVAC system. This component sits in the outside unit of the system and is responsible for transferring heat from indoor air to the outside.

The compressor achieves this purpose by compressing the refrigerant from the evaporator to release the heat into the cold air blowing over the coil. As the gaseous refrigerant turns into cold liquid, it releases all the warm air it absorbs from the indoors to the outside environment.

5. Blower Motor

A blower motor can be a small component but a very important one in the system. For starters, it’s responsible for moving air through the HVAC system.

The motor is usually located in the furnace and is connected to a series of belts that turn the fan. When the fan spins, it helps to move air through the ductwork and into the house.

After this, the warm air can easily be distributed to various rooms or heating zones in your house as desired, and all of it is controlled by the settings on the thermostat.

As long as the blower motor is spinning, warm air will continue blowing into the house. But once the desired temperature is achieved, the thermostat directs the system to stop.

6. Evaporator Coil

Lastly, in answering our question “what are the parts of an HVAC system”, our final part is the evaporator coil. It is in the evaporator coil where heat from the indoor air is extracted using the cold refrigerant.

The process here is quite simple. And follows these steps:

  • The air conditioner turns on
  • Cold refrigerant from the compressor gets into the evaporator  
  • Hot air is blown on the coil
  • The refrigerant absorbs heat from the air, also condensing the humidity
  • The refrigerant goes back to the outside unit, where it releases the heat
  • Condensed water vapor from the indoor humidity is also drained outside

The process ensures that our home’s indoor temperatures remain at optimum levels for maximum comfort.

Don’t hesitate to contact a qualified technician for any HVAC issues or maintenance queries for expert advice or service. Remember, your home’s comfort is paramount in any season.

Subscribe to Direct Air Conditioning, Inc.'s Blog

Get Direct Air Conditioning, Inc.'s latest articles straight to your inbox. Enter your name and email address below.