What is an HVAC System and How Does It Work?

When we discussed about the What is HVAC system and discussed what does HVAC its means? also and How does it works? So, for this we mentioned some components and equipment’s or full process just to give the exact idea.

what is HVAC system

Many house owners know the meaning of HVAC, HVAC means (Heating, ventilation and Air Conditioning). And many people know the basic working of HVAC. But most out of them only few peoples know that how many things are included in HVAC system.

This is very easy to understand. How many times do you really think about your furnace, HVAC equipment’s and any type of air conditioner? Few people never every purchased a brand new furnace and also they don’t have to do more work rather than their regular HVAC maintenance of existing system.

When you are ready to do new investments, though, if you are building your new House or you want to replace your previous HVAC system. You pay to understand what’s what.

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If you come to this point and want to know more about HVAC equipment’s, than visit Tempindoors articles because it is one of the best resource to get all the information about HVAC. If you still working to put the grip on this industry, then this article become a primer for you. At the end of this article you will be able to a proper and clear understanding of HVAC and its processes. So, in result your conversations with your HVAC contractor will become more effective and productive.

Read More: Furnace Installation Process Step by step Complete Guide

What is HVAC system?

Basically HVAC is a technology, equipment and procedure which goes for heating and also cooling or ventilating the commercial or any residential properties. Equipment’s which is included in this list is such as: Air conditioners, air handles, heating pumps, ductworks, filters and lines of ventilation, humidifiers and other various products etc.

Let’s discuss each furnace for more clear understanding.

Heating Equipment’s of HVAC:

Various house having a furnace which provide heat to their house. Furnaces may vary in power resources and types such as:

  • Natural gas furnace.
  • Propane furnace.
  • Geothermal power furnace.
  • Oil furnace.
  • Electric furnace.

Now a day’s natural gas furnace is very common type of furnace, but I do not mean that electric furnace is not so much popular. Well, I have to tell you that electric furnace become more popular in various parts of country, especially where weather is not so much cold and the gas cost is not low.

Read More: Popular furnace brands

Blower motor is also included in the heating equipment’s through which air moves all over in your house.

This function is also known as forced system of air. Which distribute the air throughout your house through blower motor using the duct.

Ventilation Equipment’s of HVAC:

In ventilation there are many processes which helps to move the air throughout your house and system of HVAC. It normally includes such as ductwork, ceiling vents and wall, floor and all other ventilation shafts including PVC pipes and chimney flues for the indoor ventilation of the equipment of HVAC.

Basically the ductwork of house is designed in such a way to provide air which come from air conditioner or warm from your furnace. In sufficient system of ductwork stifle the ability of systems for heating and cooling, or it will produce hot or cold spots especially where the system of ductwork which carrying the air is insufficient.

For excessive need of heating or cooling from your system furnace, there are many other ventilations such as PVC vents and chimney flues.

There are many other vents for air conditioning unit of outdoors, which distribute the air all over the house.

Ductless system of HVAC will not be included such various advance type ventilation forms. Still there is indoor and outdoor unit and the indoor unit often provide heating or cooling or some only provide cooling. All these are for individual room or for a specific area like basement or attic. For maintaining the temperature more comfortable natural ventilation process is also the part of this process,

ductless system

through this cross flow of air from windows and also from door will be very important factor for keeping the house more comfortable.

Cooling Equipment’s of HVAC:

Traditionally the HVAC systems includes air conditioner and the heat pumps in the HVAC is also work exactly similar to air conditioner. Heat pumps actually can heat or cool your house.

Heating pumps are basically connected with electric furnaces through which heating pump supplement the heating pumps ability to give efficient heat to the house. On the other hand, air conditioners are normally paired with the gas furnaces.

Cooling Equipment

How Does an HVAC System Works?

First of all, the basic thing you need to understand that equipment’s of HVAC moves the air. Generally, the system which exist move the hot air anywhere, might be in the house or out of the house. Basically house air conditioner or heating pumps and furnace normally captures or creates the hot or cold air. After that blower motor spread the air through ductwork helps to spread the air in the house.

Below we talk about the sub-system one by one and discuss the equipment and all the processes. You have to remember that the central air system of HVAC is living and the breathing system function works as whole. Heating system is not totally shut off due to cooling system and the processes or parts through which it helps the system to function properly are often overlaps.

Heating The House: How the system Works?

Basically furnace creates heat either it is produced by electrical furnace or through burning of fuel resources. Here fuel source means gas furnace but there are many others like propane or oil also.

Well, Heating pumps work in a different way when starts heating. It starts absorbing heat from the outside unit and then transfer it towards inside. But it’s not really generating excessive amount of heat as it moves the heat from one specific place to other place.

Cooling The House: How the system Works?

It is normal and very common myth that air conditioner or heating pumps starts absorbing heat from house and then travel the heat towards outside unit, from where the air is vented in the atmosphere.

Refrigerant in the cooling system is the key of this. The refrigerant is different at different pressure state such as liquid or might be in gaseous form. HVAC system depends on the refrigerant only where the pressure is.


It then starts absorbing the ambient heat and once it’s at different pressure starts removing. The heat is automatically removed by doing the process of inside and outside again and again by measuring the refrigerant pressure.

As discussed earlier, heating pumps will do the reverse procedure, like absorbs heating from the outside towards inside. At very low (cold) temperature heating pumps still start absorbing heat from the outside at very less efficient heat rate. That is why the heating pumps normally paired with the electric furnaces, because it has compatible technology and supplementing the capabilities of heating pumps heating.

Ventilation The House: How the system Works?

Here the ductwork is more clear equipment for transferring heat and cold air because the ductwork is connected to the heating system or cooling system directly.

Chimney flues and the PVC vents are included in the ventilation of heating system for discharging the excessive amount of heat. The furnace efficiency dictates that what is the percentage of your furnace energy serve in heating your house. 95 to 97% efficiency hit even in the best efficient heaters and the remaining air is normally being vented.

Read More: How does a Furnace Works?

All depends on equipment’s because the ventilation added to exits to the side of house instead of above the house. Basically this is designed in such a way to prevent the moisture condensation inside from HVAC system. For very long term period it can damage the system.

Odd and end of HVAC:

There are various items which we haven’t talk about yet, and helps big equipment’s to manage its functions. Few items are listed here, but I tell you this is not a proper list of these items inside the HVAC systems. This list is describing in such a way to tell you the basic understanding of its functions and what are the basic parts of HVAC systems.

Returning Air:

Air which is returning draws into the main HVAC system through the filters.

Exhaust outlets:

We discussed chimney flues and vent earlier clearly. Basically exhaust outlets are the areas where hot air is vented form house.


Filter should be cleaned time to time according to proper schedule maintenance. All furnaces come with 1 by 4 inch filters which traps dust particles in the air and then air passes through the filters.

Products regarding Humidity Control:

Often Humidifiers and the dehumidifiers are forgotten but plays very important role in maintaining the temperature for whole house HVAC system. It also decreases the burden on the equipment of cooling and heating through which you will be more comfortable and your system stays healthy, also increasing the efficiency of system too.

Electric Components:

Each component of HVAC is totally linked with other component of same equipment. This is actually true that when you are having multi speed system which adjust the temperature automatically. Proper controls on all of these systems done by electrical circuitry.


Thermostat is the last point through which user used thermostat to control the system. All depends on that what type of your system complexity is and how much your system need to work with other various devices. Well, many electrical inputs must be needed to complete the task in thermostat.


Basically coil is used to absorb and transfer the heat and moisture and helps the system to regulate refrigerant temperature. Coil size varies depends upon your unit efficiency.

HVAC Coils


Compressor plays an important role in the heating pumps or also in air conditioner. Through this it regulates the refrigerant pressure. Just because when your system is working. Well, especially you need to take proper maintenance to avoid various breakdowns.

Who can Service your equipment of HVAC?

For best and proper installation or service of your system requires many years for training then you will be able to do your HVAC system installation or service very accurately. Also, you need your states national certification by your areas. On other hand, simple tasks like changing of filter according to schedule maintenance are done by house owner. Well, a licensed professional contractor always take care of your furnace while servicing or doing installation and replacement of HVAC system.

Read More: Everything you know about wall furnace

There are variety of things which you need if you want proper installation of HVAC system some are like plumbing, metal works, electric works and brazing which is like welding also carpentry and much more.

During installation many testing procedure will be taken which house owners are not able to done by themselves.

First You have to learn about your HVAC system:

While professional HVAC contractor starts working on the equipment. So, if you know more about HVAC systems, through this way you are able to choose better system or accessories for your house.

Through this you will be able to get best professional HVAC contractor for your HVAC system.

Our Blog section having a variety of resources according to any level of your HVAC equipment. Check out our articles on Learn About HVAC systems through which you will continue your journey on becoming top best professional HVAC contractor.

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