What Exactly Does HVAC Stand For?

Tony Case
Written by
Last update:

What is HVAC?

If you see HVAC, you may think it's the acronym for something important, or worse, you may think it's some foreign word. However, HVAC is a perfectly common term that stands for Heating Ventilation and Cooling.

As a home owner, it is vital to understand what HVAC means because it is the system or system of systems that manages the majority of a home's indoor environment. HVAC systems come in various sizes ranging from a small home system to the large mainframe system that keeps a large office building comfortable.

HVAC systems come in two main categories: central air conditioning and central heating. Modern HVAC systems include a combined system known as a Total Building Drying System (TBDS). This type of HVAC system keeps an environment comfortable by managing humidity, ventilation, heating and cooling, in addition to providing energy efficiency.

You can think of HVAC as the heart of your home, as it pumps air and/or heat throughout your home. Modern systems use forced air and ducting to heat and cool your entire home, or just one part of your home. The system may also be ductless, where the air is directed from a central location using a blower coil, to the locations that need the air, such as the bathroom, kitchen, bedroom, etc.

How Do HVAC Systems Work?

You will probably come across the acronym HVAC when you need to have the air conditioner in your house replaced or if you want to start a business called A/C Contractors. HVAC stands for heating, ventilation, and air conditioning. So what does this mean? A HVAC system provides you with temperature control that is comfortable and healthy. Furnace and boilers are examples of systems that provide heating. Air conditioners and heat pumps are examples of systems that provide cooling. Ductwork that distributes air to every room is a critical part of both heating and cooling systems.

HVAC systems can be costly to own and maintain. If you haven’t invested in a HVAC system yet, these important tips will help you choose the right air conditioning and/ or heating system, as well as address problems in the future.

The components of an HVAC system include:

  • Compressor
  • Condenser
  • Coils
  • Filter
  • Fan
  • Dampers
  • Discharge grille
  • Louver dampers
  • Accumulator tank

The History of the HVAC System

HVAC stands for Heating, Ventilation and Air Conditioning. The system of heating, ventilation and air conditioning did not come into full fruition until the 1890–s. Gas and electric power were discovered and in the 1890–s, it was discovered that when gas and electric are mixed together, they caused a reaction that made it possible to heat, ventilate, and cool.

This was when the first units of commercial heating, ventilation and air conditioning were created.

In the 1930–s and 1940–s, advancements in technology and technique caused HVAC to advance. In 1941, the Carrier Air Conditioner Company was formed by Willis Carrier. The Carrier Air Conditioner Company is what showed the public just how efficient this method was.

It would not be until the 1990–s that a new type of HVAC system would be introduced to the market, central air conditioning. The central air conditioning unit used an underground piping system to circulate cold water from the outside to the entire home. Before central air condition units were available, the central air called for individual air conditioning units.

Doherty, ONeill, Rotary Phase Change, and Blower Door

Your home’s heating and cooling system (HVAC) is what helps to obtain a comfortable level of heating and air conditioning. Yet, the heating and cooling processes are significantly different. In the most basic terms, cooling a building requires removing heat from inside the house and thus involves a cooling process, whereas heating a house it is necessary to add heat to it and thus involves a heating process.

In addition, both HVAC systems and heating systems have a number of potential downsides. Because of this, manufacturers have been working to create HVAC systems that offer more benefits and fewer pitfalls to their customers.

What HVAC systems offer now may surprise you, and which system is best for you may be an even bigger surprise. In this blog post, we’ll discuss the history of HVAC, as well as three types of HVAC systems that are both available and more eco-friendly than traditional systems.

Types of HVAC Systems

Room air conditioners are for individual rooms while central air systems are for the whole house. In other words, room air conditioners cool a single area while central air systems cool an entire home from a single location. When compared on a cost-per-square-foot basis, central air is predictably more expensive than room air conditioning for the same area.

Evaporative Coolers

Evaporative coolers use a fluid to transfer heat to the air while adsorbing the heat into the fluid so it can be later dissipated from the air. This type of cooler is only effective when the outside humidity is low, otherwise, they leave the air in the home almost as hot as the air outside.

If the temperature outside is 100 degrees and the humidity is at 50 percent, the temperature inside will be only slightly better. If you are interested in adding an evaporative cooler to your home, you should make sure there is already a pond in your backyard.

Forced-Air Central Air Conditioner

A forced-air central air system circulates air through ducts and tubes that make contact with cool surface materials like air conditioning units and radiators. All forced-air central air conditioners have a blower and a compressor.

The blower circulates air through the unit and the compressor pumps gas to the air conditioner. There are three basic types of compressors.

Heating and Cooling Split Systems

If you are in the market for air conditioning services around the Saint Petersburg FL area, there are many different factors that you will want to weigh in on to make sure you pick a good HVAC company. It is important not only to consider price, but also other important aspects of a company, such as how often they are in the area and what kind of reputation they have. Here are a few guidelines to consider when making your decision.

  • How long has the air conditioning company been in business?
  • Is there a local paper or local BBB site where you can get some feedback on the company?
  • How long will the installers be in the area for installation?
  • Why do you need to choose this company specifically?
  • Are there any guarantees on the work that they do?
  • What are the best and worst things that have been said about the company?
  • Do they have any complaints from former customers?

There are many companies that are available in the local area for air conditioning installation, but how can you know which one is going to suit your needs the best? Take the time to look into these areas before choosing a company to work with to make sure you are getting a quality service.

Hybrid Split System

If you live in a cool climate, you may find that a simple air conditioner is not enough to provide you with a comfortable indoors. However, central air systems seem to have the right amount of power, but they’re quite expensive in both time and money to install.

The low energy high-velocity air conditioner seems like a natural solution to this problem, but the constant power supply for the compressor is too costly and it can’t pump the volume of cool air required in a continuous process. That is why air conditioning contractors have developed a new type of air conditioner called the hybrid split system HVAC that will save you time and money.

The Hybrid Split System HVAC is a combination of both central air and a low energy high velocity air conditioner. This combination allows you to have the best of both worlds. You can have a central air conditioning system that will give you a consistent cool air flow, but you can also have a separate system that will provide you an instant cool air flow when you need it.

This type of system is great because it's getting an immediate cool air flow without waiting for the compressor/air handler to warm up. It will also save you electricity because no power will be wasted in running the central AC system and it also saves you time because you no longer have to wait for the central AC to warm up.

Duct Free (Mini-Split)

If ductless mini-split air conditioning and heating isn’t your thing, at least you’ll impress your friends by being able to define HVAC: Heating, ventilation, and air-conditioning. To know more about the topic, read our detailed HVAC Guide.

In short, while your goal for a comfortable home is undoubtedly air-conditioning, your goal for HVAC may be efficiency.

Packaged Heating and Air

Air conditioning and heating in houses is not very old. From the late 19th century when it was installed in the Royal Palace of Spain to the mid-20th century, it was still not known to most of the world. Only privileged few around the world were able to enjoy air conditioning and heating.

But in the 1950s, the world began to learn about this new heating and cooling system. It was later that the system was installed in residences in USA during the 1960’s. Since then, the system has been widespread and has become a standard feature in most of the residences here.

The modern central heating and cooling system in houses today is known as the air conditioning and heating system, also referred to as centralized home heating and cooling system. There are a number of air conditioners and heating and cooling products called packaged systems, which are installed in houses as well as in buildings.

The modern air conditioning and heating system consists of a condensing unit, air handler, and air ducts. The air conditioning and heating system is popular because it combines the heating and air conditioning units. It provides room heating and cooling through the use of thermostat. There are a number of companies that manufacture the air conditioning and heating systems.

Main Components of any HVAC System

A typical heating, ventilation, and air conditioning system is going to have some major components that you should be aware of. If you are purchasing such a system for your home, knowing the ins-and-outs of each component can help you be an informed consumer. Also, sometimes these items are things you’ll need to repair or replace, and knowing the right name of the part can make it easier to do that.

Condenser: This component of your HVAC system is used to hold the compressor, and it helps condense the warm refrigerant gas that has been extracted from the evaporator.

Coils: You have two coils on the inside of the condenser, and they actually work together to cool down the refrigerant.

Compressor: Also known as the “evaporator,” the compressor is used to compresses the refrigerant before it’s sent to the inside of the condenser coils.

Condenser Coil: The two condenser coils are used to cool the refrigerant so it can be changed from a gas to a liquid.

Evaporator: The evaporator has two fins that are used to control the flow of refrigerant into the system.

Starting Capacitor: This part is used to start and maintain the current flow of electricity to the compressor.

Heat Exchanger

Any reputable Heating and cooling contractor, service groups or dealer will use a central measurement for HVAC…

The heat exchanger is a vital part of the HVAC system in your home. In a nutshell, the heat exchanger transfers thermal energy from one medium to another, for example a home’s air heats and cools via the heat exchanger.

In terms of the HVAC system of your home, the heat exchanger is an important piece of metal tubing that retains heat produced by a furnace, boiler or heat pump. All the heat that heats a home radiates through a “heat sink.” The most common heat sinks use air or water in the HVAC system.

It should be pointed out that water is almost always used as a heat sink (heat exchanger) in air conditioning systems. The water which encircles the pipes used in delivering the chilled air to a home also is used in the heat transfer process.

Blower Motor

Run Capacitors: Big, Metal, and Expensive

When you turn a regular fan on, it runs nice and smooth. Not the motor that runs the AC. The blower motor runs a bit continuously, especially if you live somewhere where the weather is hot or humid very often. That’s because the blower motor has to run a long time, more often, to maintain a constant temp in your home, which requires more motor use, which causes the motor to run hotter, which requires a longer run to keep up.

Now the run capacitor is a small electrically operated object that’s responsible for increasing the chances of the blower motor actually starting. There’s a pretty slim chance that it’ll actually start on its own, so the capacitor creates a surge of electricity to get the job done. The downside to this capacitor is that it’s fragile, and regularly need replacement to keep the motor running.

The running capacitor will expand and contract with the heat of the motor and eventually wear out which will cause it to stop working. There’s no real way to know if the capacitor is the problem or not. There are ways to test it, but if it’s gone, then it’s time for a new one.

Combustion Chamber

Houses the furnace burner, draft inducer and blower. This area must remain clean and free of lint.

Air Filter: Traps dirt and allergens in the air to be fully filtered before being circulated in your home. Change your filter every one to two months and purchase high-quality filters to ensure the most efficient air flow.

Thermostat: As the indoor temperature rises, the sensor in the thermostat cycles the blower on and off at specific intervals.

Evaporator Coil: Houses the refrigerant. This extremely cold coil provides cooling to the system by emitting heat to the atmosphere.

Condenser Coil: Houses the refrigerant. The condenser coil takes heat away from the home and dissipates it.

This easy to follow process of refrigerant co-generation is utilized in a variety of ways to reduce operating costs, move towards greener sources of energy, lower greenhouse gases, and dramatically improve the efficiency of existing air conditioning systems. Refrigerant reclamation is an efficient alternative to systems that produce emissions.

Condenser Coil/Compressor


Air conditioning is basically more than just one part. When properly wired, an air conditioning unit is supposed to keep your house warm in the winter and cool in the summer. The mechanism that makes this possible is the evaporator coil. This is responsible for sending cool air throughout the house. The main job of the evaporator coil is to take water and leaves out of the air and send it to the compressor which will compress the air or refrigerant. The refrigerant is compressed into a liquid and passes through the condenser coil and then collected in the receiver and liquefied again.

Evaporator Coil

Cold Air Duct.

There are three main parts to a heating and air conditioning system: the furnace or boiler, the blower system, and the cooling coil. The cooling coil is sometimes called the "condenser" and is designed to absorb the warmth in the air. This warm air is released out of the vents.

The cooling coil is connected via aluminum lines to the evaporator coil, which brings us back to the definition of "HVAC." The evaporator coil is often thought of as the heating coil, but it doesn't actually provide any heat to the air. A fan blows warm air over the evaporator coil, pulling the cool air from the cooling coil. This cool air absorbs the warm air from the room. The process is then reversed. A system like this brings air in from outside (drafts can be prevented with vents and ducts).

The advantages of this process are that it doesn't lose heat through the air vents and that the air can be blown farther into the room.


Controls, an Air Conditioner and a Heat Pump.

An air conditioning and heating system is a mechanical system used to create a comfortable indoor environment, by controlling naturally occurring thermal energy. In our case, the indoor environment is your home; the thermal energy is the air inside your house.

A heater does just that: keeps your home warm. When a heating system is first turned on, there is no high efficiency until the system warms up.

An air conditioner is just the opposite. When a home is first turned on, the air conditioning might not be at the top efficiency until the system has cooled the house.

Air conditioning systems are sometimes referred to as heating systems. A forced air system is one that is present in many homes. It includes an air handler (which moves the air), a heat exchanger (which is a metal coil that transfers heat from one system to another), and a filter (which removes dust from the air).

A heat pump is a mechanical device used to heat and cool a home or other building. A heat pump requires energy to perform this heating and cooling, but provides a much more efficient source of heating and cooling than older standard methods. The most efficient way to get heat into the house is by using a heat pump. Many are now using a combination system using a gas furnace and a heat pump.

Frequently Asked Questions

What’s The Difference Between HVAC And AC?

Hot air is your air conditioning, while cool air is your heating.

What Are The Main Differences Between Air Conditioning and Heating?

Your air conditioner removes humidity from the air while your heater warms it. Your heater also warms the air you exhale from your lungs.

How Do Air Conditioners And Heat Pumps Work?

The HVAC system in your home brings in cool, fresh air from outside. The fan pulls air into the building and pushes out dirt, smoke, stale air, and cooking smells. The heat pump works the opposite. Instead of moving air from the outside, a heat pump moves the heat from inside out, pushing it into the air.

What Is The Difference Between Mechanical and Electrical Systems?

A mechanical system powers the motor and pushes the air, while an electrical system powers the fan and blows the air.

How Do Air Conditioners Work?

Air conditioners reduce the temperature in a room by removing heat and pumping in cold air. Air conditioning is complicated to explain, but in simple terms, the device will suck in warmer air, cool it, and then blow it out into the room. Over time, the unit will restore its cooled air to repeat the process over and over again.


Heating, Ventilation and Air Conditioning is one of the most important areas in the home when it comes to energy efficiency. As technology has advanced, it is now possible to achieve higher levels of efficiency without having to resort to the kinds of gimmicks that were used in the past. The technology that is used today is simple to understand and operate and has more to offer when it comes to safety and control. What has changed is the level of quality and efficiency that is now available in the systems used.