HVAC systems, also known as heating, ventilation, and air conditioning, are vital parts of many buildings. Residential homes and offices, medium-large industrial buildings, hospitals, vehicles, and marine environments all require HVAC systems to keep their environments at a comfortable temperature and humidity level. These systems use a combination of outside air and fresh air to regulate temperature and humidity.

HVAC systems come in a variety of shapes and sizes, and can have separate or combined components. A combination system may use a single blower to move air throughout a duct system. The first step in the HVAC process is ventilation, either from the outside or within the home. Natural ventilation allows air to circulate and replenish oxygen, while mechanical ventilation helps to remove moisture and odors.

Packaged systems contain the heating and air unit, and are often installed on a roof or near the foundation. They are easy to maintain and have great energy efficiency. They can be powered by gas or electricity. Packaged systems are perfect for houses with limited space. The most popular type of HVAC system is the split system.

When choosing a HVAC system, it is important to pay special attention to the type of material used in the duct system. The material should be durable and easy to read. A good duct liner or duct board will reduce the risk of mold growth.