HVAC stands for Heating, Ventilation and Air Conditioning. Each of those areas refers to several major pieces of equipment and functions that heat and cool a home or other building.
If you needed that answer for your book report, there it is, Kevin. I hope you get an A+ on the presentation. For homeowners with HVAC systems, though, we recommend you keep reading to discover what you should know about your HVAC system to stay comfortable.
Because it’s a myth that you don’t need to know much about the heating and cooling in your home. Nothing terrible will happen, but knowledge is power. And in this case, it can be money too.
We’re in the business of keeping heating and cooling systems running smoothly, and saving money for our customers. Whether or not you’re near us in the Sacramento area, we want to help you to be more comfortable and enjoy more affordable comfort.
Equipment in an HVAC System
For reference, we’re going to be focusing on residential HVAC systems in this article. Much of the information is applicable to commercial systems as well, but there are some differences that we’ll be ignoring. We specialize in residential HVAC, and so this is where our expertise is greatest.
Below is a list of major pieces of equipment in a typical HVAC system. Not every home will have each one, but every home will have most of these:
- Air Conditioner – air conditioners have two primary components: an indoor and outdoor unit. The indoor unit houses the evaporator coil, which removes heat from the air. The outdoor unit has a condensing coil that allows the unit to emit the warm air into the atmosphere.
- Furnace – Furnaces, often simply called heaters, warm the air in the home. The is generally done through either electrical or gas power, though other less common fuel sources exist as well, such as oil, coal, corn or geothermal.
- Heat Pump – Heat pumps act as both heating and cooling units, and operate much like an air conditioner except with an additional reversing valve that allows the equipment to pump warmth into the home as well. The heating portion is often supplemented with electrical heating coils housed in an air handler, for supplemental heat during the coldest months.
- Ductwork – Think of ductwork as the veins of your HVAC system, and hot or cold air as the lifeblood of the home. Similar to actual veins and arteries, clogs in your ductwork can have severe consequences.
- Vents and Pipes – Gas ventilation pipes exist in gas-powered systems, and condensate vents exist in any unit to prevent moisture buildup.
- Filter – Sometimes called a furnace filter, that’s a misnomer since your filter works any time the air is running, whether it’s cooling, heating, or simply circulating air. It removes particulates from your airstream.
- Blower Motor & Fan – The motor controls the movement of air throughout your system. In more sophisticated HVAC tech, the blower motor can operate at different speeds to better heat and cool your home consistently.
- Humidifier or Dehumidifier – These are optional add-ons but exist in many homes. Whole-home humidity products can prevent the worst problems associated with high or low home humidity. Either can be attached to your ductwork to more easily treat and circulate the air.
- Gas Line – Gas lines exist in homes with HVAC systems that use gas fuel. Many homes can be converted to gas but often need a gas line installed or turned on by the local gas company.
- Thermostat – The “brain” of the HVAC system, monitoring and controlling system health, temperature, humidity and more. More advanced systems can be set to a schedule and controlled via an app.
- Air Purifiers – A less common add-on, these can be valuable in keeping your air clean and free of bacteria, viruses, allergens and other pollutants.
- Electrical Wiring – Electricity runs through any system, and also has to connect the thermostats to any and all of the equipment listed above. More complicated electrical work during an installation can often require a licensed electrician to perform.
- Ductless Units – These will exist outside the central air system and as the name implies are not connected to ductwork. Ductless units generally heat and/or cool a single room or area of the home, and are not large or powerful enough to treat an entire home.
- HVAC Accessories – There are whole hosts of small add-ons you can consider to improve your quality of life. Window fans, ceiling fans, remote sensors for your thermostat to ensure proper heating and cooling even in the most remote corners of the home, and more.
Many of those systems have numerous sub-systems and individual parts.
Some are surprised to consider all of that, because it means that HVAC can include sheet metal cutting, electrical work, work on gas lines, and involves laws of thermodynamics and complicated calculations to measure things like static pressure and airflow. In other words, a lot is going on! The result, though, is a comfortable home.
Heating
Technically speaking, heating can include a lot of items in your home that aren’t connected to your central air system. Decades or centuries ago, the “heating system” would have been a fireplace, or perhaps letting the sun shine in the windows during the daytime.
These days, though, some form of universal home heating is expected in the vast majority of homes (if you live in the warmest regions of the country, this may not be the case). From baseboard heating to window and ductless heaters, all the way up to complicated HVAC equipment that requires professional licensure to install.
Electric furnaces are becoming more common, for instance. These are units with electric coils housed in them, which heat the air before it’s distributed through the home.
Gas furnaces utilize burning natural gas to produce heat. Since this also produces potentially harmful gasses, the heat must travel through a heat exchanger first, which separates harmful gasses from heat, and the harmless hot air is then transferred to your home. The excess gas is vented, usually through a flue pipe that exits your roof.
Heat pumps, as their name implies, can also provide heating, though many are better known for providing cooling since they look extremely similar to an air conditioner.
Air Conditioning
Your air conditioner or heat pumps is what cools your home in a typical residential HVAC system.
The evaporator coil in the indoor unit of the home collects heat and moisture, which is then captured and transferred into the refrigerant line. Your refrigerant changes states, from liquid to gas depending on whether it’s at the indoor or outdoor cooling unit. This change in state allows it to absorb or emit heat.
Once outside, the heat is emitted and vented out of the outdoor cooling equipment. You likely recognize this from the large outdoor fan that runs when your home is being cooled.
The refrigerant then travels back into the home and absorbs more heat. This process continues until your home reaches the desired temperature that you have set on the thermostat.
Heat pumps work identically. They simply have a reversing valve to be able to add heat to the home instead of simply removing it.
Ductless mini-splits are also known for their cooling, although these days most are also capable of heating as well.
And lesser cooling units like those installed in windows work on similar principles; they simply don’t cover the entire home like a ducted system does.
Ventilation
The forgotten letter in the HVAC acronym, ventilation ensures that everything we talked about above works properly.
Ductwork needs to be adequately sized and formed to allow air to travel without bottlenecks, backups, or loss of air pressure in the system, which would cause some rooms to not get airflow. It also needs to be properly sealed and insulated.
Vent pipes and flues need to be installed that remove excess moisture and harmful gasses. The nature and angle of these flues varies depending on the type of system you have. You may need a flue pipe that runs straight up through your roof, but it’s also possible that this would be ineffectual. In these instances, a slanted PVC is usually run through the side of the home to provide proper ventilation.
The DIY version of this is simply running fans or opening your windows, and this can be a great way to keep your air healthy as well! However, this isn’t always possible or ideal (such as when air pollution or weather prevents natural airflow from providing comfort and healthy air). This is when your HVAC system is needed.
Air Quality and HVAC
This leads us naturally to air quality. We’ve written a lot more about HVAC and air quality, since it can affect the health of everyone who lives in a home!
ALSO READ: HVAC and Indoor Air Quality
Just to scratch the surface of what HVAC can assist with:
- Reduce bug infestations through humidity control
- Prevent mold or mildew buildup
- Kill or capture bacteria
- Kill or capture virus particles
- Reduce allergens, smoke and other airborne pollutants
- Reduce pet dander and hair
- Help you sleep better due to easier breathing
- Protect from poor air quality days in major urban areas
- Reduce or prevent dry and cracked skin in the winter
- Shorten or eliminate flu season for your family
While none of those are guarantees, we’ve seen each of them enough times to know that it’s possible for families who closely safeguard their indoor air with the proper HVAC services and technology.
Understanding HVAC Equipment Quality
Air conditioners, furnaces and heat pumps come in a lot of makes and models, but what differentiates them?
Sometimes, the answer is not much. A 16 SEER air conditioner (Note: SEER is a measure of efficiency) from one manufacturer is going to be similar to a 16 SEER model from a different company. A lot of the difference is the quality of the installation, frankly, which makes choosing an HVAC company extremely important.
However, differences do exist. The biggest for most homeowners is in staging. Broadly, staging falls into three categories:
- Single Stage – the unit is either 100% on or off.
- Two Stage – The unit has a second power setting that allows it to heat or cool more slowly, which improves airflow and more evenly heats your entire home.
- Variable Speed (aka Multi-Stage) – These units can have three all the way up to hundreds of stages! They allow for the most sophisticated and energy-efficiency heating and cooling.
Naturally, variable speed equipment will be the most expensive, but these are also often the units that are eligible for the best local, state and federal tax credits and rebates.
The choice of which will be best for you isn’t one we can answer for you. However, a knowledgeable HVAC expert can explain differences to you and help you make the best decision for your home and budget.
HVAC Contractors
HVAC companies are not all created equal. They’ll all perform the job to some degree of accuracy, but the difference between a good installation and service and bad service can mean years of life off the lifespan of your system, and increased energy costs year-to-year.
Ask your contractor what certifications the company holds. Check the quality of their online reviews. Ask your neighbors who have used them. Getting a good picture of a company isn’t tricky, but the best ones want to do what’s right for you instead of simply making a sale, since they know this will lead to long-term business.
Learning More About Heating and Cooling
The first step is to schedule an appointment with a licensed HVAC contractor. If you’re in the Sacramento, CA area, we hope your first call is here to CABS Heating and Air Conditioning.
Regardless of whether or not you’re in our service area, though, you can learn a lot more in-depth information about the HVAC industry on our Learning Center. It has in-depth articles and videos covering every major topic is residential HVAC. And it’s written and vetted by industry professionals, not artificial intelligence bots or unpaid interns.
We hope you find value in not just our Learning Center but our entire suite of home services.
