What is an HVAC System? A Guide to Understanding Your Home’s HVAC


Can you imagine that not too long ago, we were living without an HVAC system? Scorching and steamy hot summer, and harsh and chilly winters. Just recently in Boston, they have experienced their “snowiest” days –that’s 24” of snow! It may look like a winter wonderland, but it sure is freezing cold. Having an HVAC in their homes will surely make things more comfortable and safer. Historically, it was the mid-1800s when the general idea for centralized HVAC was born and has evolved since then, giving comfort to homes, businesses, laboratories, hospitals, and more.

Did you know that air temperature is so important to homes that more than half of the energy is for heating and air conditioning? Most of us probably view HVAC as a need and not a luxury. But first, what is an HVAC system? It stands for “Heating, Ventilation, and Air Conditioning”. In a nutshell, your HVAC system is responsible for cooling and heating your home by feeding the cooled or heated air through the ductwork. Plus, it also provides better quality of air (the V in HVAC), as it replaces the air within the space, removing the smoke, odors, airborne bacteria, gas, and more. The three main functions are interrelated, and though it may seem like the process is fairly simple, there is actually a lot of moving parts involved to deliver the right temperature to your home.

Most homeowners probably don’t think much of their HVAC until it stopped working, or they need to replace it, but it is a wise move as homeowners that you know how every aspect of your home works especially if you need to invest in a new one. It will also give you an idea of how to take care of it better. So, let’s start with the basics…

The “anatomy” of your HVAC system:


    1. Thermostat – this is one of the “stars” of your HVAC system. This is also the most visible part of HVAC system and the one that you interact with the most. The best part to put it is in easily accessed walls. It is the one responsible for sending the “signal” or instructions on the temperature of your liking to your HVAC, which can be set either manually or it could be programmed. In addition, if your thermostat “notices” that the temperature is higher or lower than your set point, it will act accordingly to adjust the temperature.If you are planning for an upgrade, a smart thermostat is a way to go. It is easier to use and more efficient. Some of its best features are app integration, voice activation, and scheduling features, where you can do pre-programming based on your schedule and routine.
    2. Heating – most houses will have a furnace or a boiler to heat homes. There are different varieties of furnaces that utilize different fuel sources like oil, propane, natural gas, and electric gases. The most commonly used are natural gas furnaces. Your furnace is typically found in either your attic, basement, or a specially built closet.Here’s how the process works for your furnace:
      • Gas comes into your furnace through the pipes, lighting the furnace burner.
      • The burning gas will now meet the cold air from your home, and by doing so, the cold air is now warmed out with the gas within the furnace heat exchanger.
      • The vent will be piped out the exhaust from the interaction between the hot gas and cold air and will be pushed outside your home using the exhaust pipe.
      • The newly warmed air will be directed through the different ducts in your home by the blower fan inside the furnace. And more cold air from your house will be directed to the furnace using the return ducts.
      • The process will be on repeat until the desired warm temperature is reached.

      Note that for milder climates, homes can use heat pumps (this also has cooling functions and could work all year round)

    3. Cooling – this is where the air conditioner comes in. It uses electricity and refrigerant to cool the air. In contrast with furnaces, air conditioners are usually installed outside your home.It works by taking the humidity and heat from your home and releasing it outside, thus dropping the temperature in your home. Here’s the shortened process:
      • The hot air inside your house is pulled out by the fan from the indoor part of your air conditioning unit.
      • Dust, debris, lint, and more are filtered out from the air.
      • The now filtered air is pushed over the evaporator coil (this is the part that gets filled with liquid refrigerant). The said coil will absorb the heated air, turning the refrigerant into gas.
      • The cool air is now inside your home.

      Surprisingly, one of the most common questions that we hear is if there is a difference between an AC unit and an HVAC unit. AC is designed to cool your home and its functions stop there, while your HVAC has a wide array of functions—cooling, ventilating, and heating your home and air conditioning units are only under the umbrella of an HVAC system

    4. Ventilation – ventilation is responsible for distributing the cooled and heated air from the duct system throughout your home. It includes your vents (typically found near your ceiling with angle slats to send air downward), the ductwork, and ventilation shafts.Note: Make sure that your vents are not blocked otherwise the cooled or heated air will not come into your home. Also, if your ductwork is inadequate, expect that there will be an imbalanced temperature in your home, where some areas will be hotter or cooler.

Here are some types of HVAC systems that you can consider:

      1. “The classic” – Split Heating and Cooling Systems – this is widely used, where it has components both outside and inside of the house. Normally, it will have an outdoor component like the AC unit and an indoor component like the furnace with a fan or an evaporator coil. It will also have ductworks to circulate the air throughout your house. For newer types of split systems, it will also include humidifiers, air cleaners, UV lamps, and more.
      2. Ductless Split System- the name speaks for itself, this efficient system is designed to properly function without ductwork. Only small holes are drilled in walls and it has inverter-driven compressors. It is a good option for spaces where distribution ductwork can’t be added. Similar to the classic split type, this system type also has accessories that help improve air quality in your homes.
      3. Zoned System – this type of HVAC allows you to cool or heat various areas of your house through dampers within the ductwork. These dampers allow you to selectively block airflow. This system will help you save money, as you can choose what areas to be cooled or heated at specific times. This is a good choice for larger houses, multistory houses, or those with multiple wings.

Tip: Also, no matter what type of HVAC system you are using the key for it to last is through proper maintenance. The average cost for maintenance of your entire HVAC system is around $150 to $500.

What steps should you take before installing an HVAC system:


      1. Identify your cooling and heating needs
      2. Know the suitable size of the HVAC system for your home – When choosing your HVAC system, always remember that “bigger is not better”. An oversized system will cause a number of issues, like short cycling issues (the temperature will result in your system starting up or shutting down in rapid succession) and higher energy costs. Your contractor will be able to help you determine the right size for your home.
      3. Make sure that your schedule is cleared during the installation – the process could range from a few hours to even a full day. And in case your technician has any questions for you, you will be available.
      4. Always hire a professional and licensed HVAC contractor – Your HVAC system is comprised of different moving parts and various skills are needed to ensure that the installation is done correctly. Do not attempt to do this on your own, aside from not having special equipment, some of the skills required are plumbing, metalworks, electrical works, and more – you won’t be able to Google these all.

Your HVAC is one of the best investments that you can have for your household. It is a necessity, especially since it is not only for heating but cooling your house, but it also comes with health benefits. With the proper ventilation it provides, you can now stop worrying about poor air quality and be assured that your home is free from irritants like dust. If you are thinking of having a new system installed in your home, it is best to make thorough research and ask for different quotes. We have to stress though that your HVAC system should be installed by professionals.

Bonus tip: If you are upgrading your HVAC system, aside from hiring professionals, make sure that the proper rating and certifications like AHRI, AFUE, SEER, MERV Rating, and HSPF are in place. You can ask about all these certifications from your trusted HVAC contractor.

Leave a Reply

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