When you think of your HVAC (Heating, Ventilation, and Air Conditioning) system, you probably picture that big metal box outside, the vents in your rooms, or maybe just your thermostat. But did you know your HVAC system is more like a team of specialists working together than a single machine? Understanding this “teamwork” makes it easier to see why maintenance, upgrades, and repairs can make such a huge difference in your comfort, air quality, and even the longevity of your home.
The “HVAC System” vs. “HVAC Components”
Let’s break it down:
- The HVAC System is the entire network of equipment, ductwork, controls, and devices responsible for controlling temperature, humidity, and air cleanliness in your home or building.
- HVAC Components are the individual parts that make up this network. Each has a job—like generating airflow, transferring heat, filtering particles, or removing moisture.
Think of it like a baseball team:
- The system is the whole team, playing together to win.
- The components are the players: the pitcher (air handler), catcher (thermostat), outfielders (ductwork), and so on.
How the “HVAC Team” Works Together
Your HVAC system interacts with your conditioned space (the rooms you live or work in) through six main functions:
- Airflow Generation
- 3 Forces Driving Air Movement Between Spaces: *Where An Airflow Pathway Exists*
- Pressure: Air flows from higher pressure to lower pressure surroundings. (Letting air out of a balloon)
- Temperature: Air flows from higher temperature to lower temperature surroundings. (Leaving attic hatch open in the summer draws in attic heat)
- Moisture: Air flows from higher humidity to lower humidity surroundings. (Placing wet electronics into dry rice to wick out the moisture)
- HVAC Component(s) Involved:
- Fan/Blower: Generates the pressure differentials between the conditioned space and the HVAC equipment to facilitate airflows across the HVAC system and its internal components.
- The pressure differentials generated by the HVAC system’s Fan/Blower have by far the highest impact on the pressurization profile and air movement patterns of a building serviced by the HVAC System, having a more profound impact than all other internal and external factors combined for a home or building. It’s the #1 Air Movement Influential Variable in a home.
- Fan/Blower: Generates the pressure differentials between the conditioned space and the HVAC equipment to facilitate airflows across the HVAC system and its internal components.
- Building Factor(s) Involved:
- Building Envelope Tightness: External environmental factors such as wind affect air infiltration and exfiltration rates, as well as how the building pressure profile is maintained between adjacent rooms in the home or occupied space, and the building envelope determines how significant of a contribution these external environmental factors have on the indoor environment and the airflow distribution within.
- U.S. Homes constructed after the 1970’s energy crisis underwent significant changes to their air tightness construction methods due to building code changes which resulted in much tighter homes that are less vulnerable to external factors like windy conditions, but also frequently lack the fresh air ventilation capabilities of homes constructed before these building code changes.
- U.S. Homes that were from the 1960s or earlier tend to have higher ventilation rates affecting air infiltration and exfiltration driven by external wind factors, and higher energy usage rates as a result; however, they do tend to have lower measured IAQ pollutant concentrations due to higher fresh air ventilation rates.
- Building Envelope Tightness: External environmental factors such as wind affect air infiltration and exfiltration rates, as well as how the building pressure profile is maintained between adjacent rooms in the home or occupied space, and the building envelope determines how significant of a contribution these external environmental factors have on the indoor environment and the airflow distribution within.
- 3 Forces Driving Air Movement Between Spaces: *Where An Airflow Pathway Exists*
- Air Movements & Airflow Delivery
- Ductwork: Acts as the highways, delivering air to and from the HVAC equipment and the various different spaces serviced by the HVAC system.
- Think of your buildings interior elements such as doors as an extension of the ductwork between your home and the HVAC equipment, as integral component that greatly influences the building pressurization and IAQ of the home or building!
- Ductwork is categorized into 2 main categories with respect to duct cleaning: Porous and Non-Porous Duct Surfaces.
- Porous ductwork surfaces describes Duct Board and Internal-Lined Metal duct types.
- Porous ductwork surfaces require the application of a surface repair coating such as Hardcast RE-500 following duct surface cleaning to help prevent the release of fiberglass fibers into the airstream when the HVAC system is returned back into normal operation… As a result, they cost more than non-porous duct systems to clean due to the additional procedures, labor, and materials involved to apply these surface repair coatings which are essential to maintaining healthy indoor air quality for your home or business.
- Non-Porous ductwork surfaces describes External Insulated Metal and Flexible duct types.
- Porous ductwork surfaces describes Duct Board and Internal-Lined Metal duct types.
- Terminal Vents: These Return “air inlets” or “Return Grilles” and Supply “air outlets” or “Supply Registers and Diffusers” influence the delivery of airflow into each room by modulating the airflow trajectory (direction), air velocity (speed in feet-per-minute), and the air volume (cubic feet-per-minute) delivered into the spaces…
- Think of vents like you would think of placing a thumb at the end of a garden hose to increase spray pressure, water volume, or spray pattern of water by adjusting your thumbs position on the hose outlet.
- Ductwork: Acts as the highways, delivering air to and from the HVAC equipment and the various different spaces serviced by the HVAC system.
- Thermal Comfort
- Refrigerant Lines & Coils: Facilitate the transfer of heat into a building from the outside environment (for heat pumps only) during heating mode, but more commonly facilitate the heat transfer from inside a building to the outside environment as air moves across the cooling/evaporator coils and heat is absorbed by the refrigerant inside of the coils while simultaneously being rejected outside of the building as the refrigerant inside of the coil undergoes phase changes between a liquid and gas vapor.
- Heat Exchanger Tubes: Furnaces contain heat exchanger tubes to transfer heat into the airstream during the operation of combustion-fueled components to generate the heat inside of these tubes.
- Electric Heat Strips: Certain types of air-handling units contain electric heat strips to introduce heat into the airstream at points within the air-handler cabinet or within certain types of airflow terminal box units occasionally installed in commercial buildings. These may also be a backup heating unit for heat pump systems during extreme cold weather conditions.
- Humidity Control
- Evaporator Coil: Removes excess moisture/humidity during A/C system operation from the airstream as air comes into contact with cold evaporator coil surfaces and begins to condensate due to surface temperatures below the dew point of the airstream.
- Dehumidifier: Removes excess moisture/humidity from the airstream using same mechanism as evaporator coils, providing a supplemental support system for the main HVAC unit.
- Humidifier: Adds moisture/humidity into the airstream during dry climate conditions commonly experienced in winter months and under continuous furnace operations.
- Air Cleaning
- Air Filters: Remove dust, pollen, and allergens.
- Enhanced Media Cabinets: Some systems include UV lights or electronic air cleaners for added protection.
- Air Purification Technologies: Some HVAC systems contain “air purification” technologies which their manufacturers claim produce airborne virus and pathogen neutralizing or killing abilities, prevention of biological contamination of coil surfaces, and that introduces electrical charges to airborne particles which they claim causes airborne contaminants of opposing charges to cluster together, ultimately becoming larger in size and easier for the filter media to capture as airflows across the filter surfaces. These technologies include: Needlepoint Bi-Polar Ionization Systems, UVGI or UVC Lamps, Photocatalytic Oxidation (PCO), and others.
- Environmental Stability (Protecting Your Home & Its Contents)
- By keeping temperature and humidity in check, your HVAC system prevents damage to wood, drywall, electronics, and even family heirlooms.
- Climate controlled environments are essential to maintaining just about any items which contain a porous surface including many types of artwork or paintings, older maps and books, photographs, fabric-containing items like furniture and clothing, and a variety of other “home contents” that would otherwise be destroyed if exposed long-term to outside environmental conditions.
The Importance of Each “Player”
If one component isn’t doing its job—say, the ductwork is leaking or the filter is clogged—your system can’t keep up. That’s why regular inspections, duct renovations, and professional cleanings are so valuable.
A high-performing HVAC system = a comfortable, safe, healthy, and protected home.
Curious about how your “HVAC team” is performing?
A professional assessment can spot weak links and suggest the most impactful improvements—whether that’s better air balancing, a duct upgrade, a cleaning, or just a simple filter change.
Ready to make your home more comfortable and efficient?
Contact Southeast Clean Air Solutions for a personalized assessment of your home’s HVAC System Operational Health, where we take a *measured approach* to determining your HVAC systems *delivered capacity* from the HVAC equipment into the conditioned spaces, as well as a comprehensive evaluation of your home’s indoor environmental conditions to ensure the health and safety of the air you and your loved ones breathe in your home.
OUR MISSION: At Southeast Clean Air Solutions, we create safer and healthier indoor environments for our clients and their loved ones.