HVAC, or heating, ventilation, and air conditioning, is an essential part of many indoor environments, from homes and offices to large office buildings and even airplanes and cruise ships. These systems use a combination of mechanical and natural ventilation to help regulate temperature and humidity. They help keep indoor spaces comfortable and safe for occupants.

There are several types of HVAC, each designed to meet the needs of a particular home or building. One type, packaged HVAC systems, consists of a furnace and an evaporator that is installed directly into a room or area. These systems are easy to install, low-maintenance, and often run off of electricity. They are best suited for homes that do not have a lot of space.

Newer HVAC systems are significantly more energy efficient than older models. They have the potential to reduce energy costs by as much as 50%. Many homeowners choose a dual system that includes both a furnace and a heat pump. Alternatively, a home with a furnace but no heat pump would have a conventional AC system.

Another type of HVAC system uses oil to heat and cool the air. Oil furnaces heat and cool air by pumping oil from a reserve tank into a burner. The heated air is then forced into a heat exchanger. The hot air is then blown back into the house. A Richmond-based company estimates that 5% of all HVAC systems use oil furnaces.