HVACs are the most commonly used system in the US that are used to provide cooling and heating. HVAC is short for heating, ventilation, and cooling. These are advanced and complex machines that are designed to perform comfortable temperatures even in the most extreme temperatures. These are widely used by Americans in their homes, businesses, restaurants, and almost everywhere.
History:
Before we dive further into the modern HVACs today, we think it’s important to mention the humble beginnings of these systems. The first ever functional system was developed in the 19th century in America. This was a time when steam was used to provide both cooling and heating, using these systems.
Then in the 20th century, we witnessed the first ever electric-powered system which was quickly and widely adopted by almost everyone. They were commonly known as the “central heating and cooling systems” and these were what started the journey towards the advanced and modern systems that we have.
How do they work and what are the components?
As most people believe, these systems do not produce cooling. Yes, you heard it right. In fact, these systems including the ACs, catch all the hot air from the inside of our homes and expel it outside. Leaving a cool temperature inside. The same goes for heating, these systems grab all the heat from the outside and provide it in our homes during cold temperatures. The magic is done by a chemical called “Refrigerant”. This is what catches the heat and expels it or provides it as per the need. We will discuss the functioning of the refrigerant and other components below, in detail.
Furnace
If a system does not have the ability to catch the hot air from outside, then the easiest and most common way is to generate the heat from inside. That is where a furnace comes in handy. The furnace is responsible for generating all the heat in the system. The most common ways it produces heat are by burning oil, electricity, gas, and more. The type of fuel it uses to generate heat depends largely on the price of the system, manufacturer’s choice, and demand in the area you are living. Not to mention that it’s also affected by the availability of each fuel source. It pretty much functions like normal heaters, the heat is transferred with the help of other components.
Cooling compartment.
Now as we mentioned before, these systems do not produce cold air. The cold airflow that you feel when placing your hand on the vent is actually the same air but with heat removed.
The whole system operates on a simple yet intuitive concept. The normal air contains heat energy. The magic chemical “Refrigerant” is placed in the system. Refrigerant is an excellent heat absorber and exists in gas form. It is compressed in the system and turned into liquid form. This liquid circulates through the coils that are present in the system. The system then takes the hot air from our homes and passes it through the coils that contain the cold refrigerant.
As the refrigerant has excellent heat-absorbing capabilities, it absorbs all the heat energy from the hot air. This drops the temperature of the air while the energy level of the refrigerant is increased. The air with less heat energy, or the “cold air” is now then passed back into our home, leaving the impression that the system is somehow generating cold air.
Coils
These coils contain the refrigerant. These are designed in a way that they can absorb the most heat while allowing air to pass over them. These are often thin and multiple in number to increase the surface area. The greater the surface area, the faster the refrigerant will absorb the heat and the more efficient it gets.
Ducts
No matter how efficient and effective these systems are in generating heat and cooling effects, they are useless without the ducts. The ductwork is what we normally don’t see in our home, as it’s hidden behind the ceiling and walls. These are massive pathways for the air to travel. The cold and hot air is transferred through these ducts to reach all the rooms of our home. The ducts are a massive net of airways that connects all the rooms in a home with the central cooling and heating systems. Without these, there will be no ventilation and no movement of air.
Thermostat
Thermostats are devices that allow us to control the temperature of our home. These allow convenient access and control of our heating and cooling system. We can change the temperature settings anytime, just by pressing a button. These devices come in analog form and smart eclectic forms.
Condensation unit
This component contains the refrigerant once it’s converted into liquid form. The job of this component is to send the refrigerant back to the evaporator coils so that it can be used again for the process of heat absorption.
Air Returns.
Just like pathways to transfer the cooled and heated air to our rooms, there are separate pathways that take the air from our rooms. Air returns are like vents fitted with filters. This allows the system to take all the unprocessed air from our home and provide it to our HVACs.
Filters
We all are aware of what the filters do and the name itself is self-explanatory. These filters are designed to catch all the dirt, dust, and contamination from the air. Some of the best filters available in the market are able to catch even the smallest of microorganisms. These filters ensure that you are provided with clean and healthy air all the time. It is also important to regularly clean your filters for maximum filtration and hygiene.
Conclusion
We hope this information answers some of the most common questions like “What is an HVAC system” and “How do HVACs work”. There could be more detail on the sub-components of each part. But for an average homeowner, knowing the above information is enough to understand how these systems work.