HVAC is an abbreviation for Heating, Ventilation and Air Conditioning. Therefore, HVAC systems are everything ranging from domestic air conditioners at home to large systems used in apartment blocks and industrial complexes. A good HVAC system provides indoor comfort through thermal control and one which is designed using the principles of thermodynamics, heat transfer and fluid mechanics. The large air conditioner boxes seen on top of apartment blocks or offices are examples of HVAC systems. They are generally deployed in big industrial buildings, apartment blocks, large interior environments and skyscrapers. They are also used as an essential component in environments where the temperature and humidity need to be kept at certain levels according to health regulations, using the air taken from outside. However, heating and cooling systems that are seen today in domestic houses also come under the category of HVAC systems. They might take a different form, but many of the fundamental principles which determine how they operate and their efficiency cross over from the smallest of domestic devices right through to the largest commercial installations.

Different Types Of HVAC Systems

For most of the people using an HVAC system, heating and cooling will more or less account for as much as half of their energy usage. Keeping this in mind, it is vital to choose an HVAC system which will not only meet the comfort requirements of the residents but also not draw on excess power and escalate the cost of living. People living in hot or cold climates may opt for a single-stage system which is designed to produce only heating or cooling. These systems are generally inexpensive compared to the multi-stage systems available. However, they are also relatively inefficient and will most likely work at maximum capacity even when not required. More advanced models offer variable fan speeds to reduce power use as much as possible but are still inefficient when compared to multi-stage systems, and are therefore more expensive to run in the long term.

On the other hand, zoned systems have been designed to heat or cool individual parts of a building. This is done by creating zone valves and dampers inside the ductwork and vents which selectively block the flow of air. For people with more massive property, this is of prime value as it prevents the system from heating or cooling areas in the building which are not in use.

Humidity control is also offered by certain HVAC systems, and options for both humidifiers and dehumidifiers can be added to heating and cooling systems. People who live in arid environments or in the tropics find these additions quite useful. However, there are people who prefer to install dehumidifier or humidifier systems to alter the humidity of their environment without using the air conditioner.