What Are The Functions Of HVAC Systems

Every household relies on heating, ventilation, air conditioning, or HVAC systems to stay comfortable regardless of outside weather. As its name implies, this home fixture keeps your family hot during cold seasons and cold during the summer.

Apart from temperature regulation, HVAC systems have other functions that make your living spaces better. Discover their additional features, alongside other components, in this blog. You’ll also understand how each part works to make you comfortable.

Main Components Of An HVAC System

Any HVAC system has the main components as derived from its name. The heating component can either be a furnace or a best combi boiler. The furnace system includes pipes that transport fluid or steam or ductwork—which will be explained in detail in the latter section—in the case of a forced-air mechanism. Regardless of the heating system type, seek the services of a licensed HVAC contractor for the repair, replacement, and installation of this system.

On the other hand, ventilation takes charge of the air’s circulation or input and output in your living spaces. Natural and mechanical or forced systems are the two main mechanisms that dictate how the ventilation system works. The natural system relies on traditional wind forces to deliver fresh air for comfort and heat reduction. Mechanical or fan-forced ventilation uses both wind and buoyancy to function.

The ventilation process is essential as it enhances indoor quality. When working at total capacity, an HVAC system can remove carbon dioxide, odors, bacteria, dust particles, and other pollutants in the air.

Apart from heating and ventilation, the HVAC system’s third principal component is air conditioning. This function removes heat from your home and replaces it with cool air. Further, an air conditioning system has four essential components that work together to provide you with comfort. These include the condenser, expansion valve, evaporator, and compressor.

Primary Functions Of An HVAC System

Now that you understand the main components of an HVAC system, you’ll have a better understanding of its primary functions below:

HVAC System Function #1: Air Conditioning

As mentioned, an air conditioning system works to keep your home cool. Besides window type or centralized air conditioning, which is often used alongside forced air heating systems, other known options for air conditioning include split and ductless mechanisms. While these technologies make future checkups and repair less complex, you’ll still need air conditioning installers to have them set up in your home. 

Traditional air conditioning systems have the following components:

  • Compressor. This part is also known as the AC’s engine as it converts low-pressure gas to high-pressure gas to release the refrigerant. This cooling compound is then passed on to the condenser.
  • Condenser Coil. The coil converts the high-pressure gas into a liquid using a fan. The liquefied cooling element is then sent to the evaporator.
  • Evaporator. This AC part is located inside the property, usually near the furnace, unlike the compressor and condenser coil. This section is responsible for turning the low-pressure liquid from the condenser into gas. The evaporator is also responsible for removing heat from the air.
  • Air Handler And Blowing Unit. This two-section unit works together to suck in room temperature towards the evaporator and distribute cool air all over your living spaces through the duct system.


Most modern HVAC systems have built-in thermostats that maintain the temperature in your air conditioning and heating systems. They can either be manually or automatically adjusted. In smart homes, homeowners can control the thermostat using their mobile phones, but if you don’t know how to use these systems, you can seek help from experts such as those at Magnolia Heating and Cooling.

HVAC System Function #2: Heating

Operating opposite air conditioning is the HVAC’s heating function. During cold seasons, your HVAC supplies and distributes warm air into your home. An HVAC system that relies on mechanical heating uses a furnace to heat the air and disperse it through the same ducts where cold air passes through when using the AC system. Your air-conditioning evaporator coils work to remove heat and humidity in these situations.

Apart from these components, the HVAC heating system relies on the following parts to provide you with warmth when you need it:

  • Furnace. This component works to heat the air distributed by the HVAC system. A furnace is generally found inside the home such as in the garage, basement, crawl space, or attic. When using a heat pump or dual system, the furnace will be placed outside the home.
  • Supply Vents. This is technically used by all systems—heating, air conditioning, and ventilation—to circulate the warm or cold air to your living spaces. The ductwork also draws the air from inside the home into the furnace or air conditioning unit. However, another component that makes the process possible would be the return vents. 
  • Air Return. These are typically larger than supply vents and usually have suctioning power. Once done sucking the air in, the system draws it through a filter before it’s transported to the central system. As mentioned, this works alongside supply vents. Air return also marks the start of the HVAC system’s ventilation process.
  • Exhaust Outlets. This is an outlet where the exhaust generated by the heating system is expelled.

HVAC System Function #3: Ventilation

The HVAC system also facilitates air circulation, allowing proper ventilation for your home. Return vents, air handler, blower, and ducts work together to provide mechanical ventilation that keeps bad or stale air out and fresh or good air in. By doing so, the HVAC system helps maintain indoor air quality.

While performing these tasks, the system also reduces humidity and moisture levels. This HVAC function also removes foul odors, dust, and potentially harmful gases such as carbon dioxide and replaces it with oxygen.

HVAC System Function #4: Filtration

So much has been said about regularly checking and replacing your HVAC air filters, and all of them are true. Without the air filter, your HVAC will get damaged. Indoor air is filled with dirt, dust particles, and other contaminants. If these get through to your HVAC system, they may cause any components to malfunction and get stuck. By trapping the pollutants and debris, filters keep your indoor space safe.

Air filters work by cleaning the air before it’s drawn into the blower and distributed through the ducts. These pleated cloths or paper filters protect your HVAC system’s blower fans. This could lead to high HVAC replacement costs that could’ve been avoided in the first place.

Bottom Line

Your heating, ventilation, and air conditioning (HVAC) system does more than warm or cool you down. By understanding each of the functions of the components, you’ll understand how the system works to keep you comfortable. Knowing these details can also help you recognize whether there’s something wrong with the system and when to call professionals to keep your unit in shape.

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