HVAC is a commonly used acronym meaning. Heating, Ventilation, and Air Conditioning. HVAC refers to the different systems used for moving air between indoor and outdoor areas (ventilation). Along with heating and cooling both residential and commercial buildings. A good HVAC system aims to provide thermal control and indoor comfort, and one that is designed using the principles of thermodynamics, fluid dynamics, and heat transfer.

While you may have seen the big air conditioner boxes on top of apartment buildings, offices, what are you seeing is the visible part of the HVAC systems. They are generally deployed in large industrial buildings, skyscrapers, apartment buildings, and large interior environments. They are also an essential component of environments where there are health regulations requiring that temperature and humidity be kept at certain levels, using air taken from outside.

However, the heating and cooling systems you are using in your home are also HVAC systems. They may take on a different form, but many of the fundamental principles are similar but with some commercial units having fresh air as part of the unit, as well as their efficiency, crosses over from the smallest of personal devices right through to the biggest commercial installations.

The main purpose of an HVAC system is more than just warming or cooling a space. Instead, it serves to improve indoor air quality and provide comfort for everyone inside a building. While there are several different types of HVAC systems, they all begin with the same essentials.

Firstly, there is a source of air or water to recover heat from to perform the heat recovery process, which is typically from outside the home/ building.

Secondly, this process is called ventilation, this part is not essential for domestic homes but is becoming more and more required because building methods, but it is essential for large volume spaces and buildings, and it happens in two different ways.

The first way is mechanical ventilation, which uses a mechanical system to move air in and out. In the past, there was plenty of natural ventilation in most homes from gaps and cracks in the construction along with the opening and closing of doors. However, modern construction is creating homes that are far more tightly sealed, so ventilation is becoming an increasingly important component in home HVAC systems. Once the air is brought in, it is drawn into an air handling unit where the work begins. Here, the air is drawn through filters to remove dirt, dust, allergens and other particles. Once the air is clean, fresh and at a comfortable temperature, it is directed into the home. Form a central system, this means moving through a network of ducts and register to different rooms. For other systems, this usually means being directed right into space.

The second way is via natural ventilation, which is the process of supplying air to and removing air from an indoor space without using mechanical systems. It refers to the flow of external air to an indoor space as a result of pressure differences arising from natural forces. There are two types of natural ventilation occurring in buildings; wind-driven and buoyancy-driven ventilation. Wind-driven ventilation arises from the different pressures created by wind around the building or structure, and openings being formed on the perimeter which then permits flow through the building. Buoyancy driven ventilation occurs as a result of the directional buoyancy force that results from temperature differences, between the interior and exterior.