Heating, ventilation and air conditioning (HVAC) equipment are climate control systems installed in buildings. Additional to providing thermal comfort they are meant to provide acceptable indoor air quality and the ability to regulate and maintain the systems. An HVAC system typically consists of central heating, forced or displacement ventilation, and air conditioning equipment.
Central heating equipment generally consists of a furnace or heat pump used to heat water, steam or air in a central location, and then distributes the heat through piping or ductwork. A forced or displacement ventilation system can also be used to control humidity or odors through heat recovery ventilators (using heat exchangers to bring the fresh air temperature to room temperature) or displacement ventilation systems (introducing air into a room at low velocities). Air conditioning equipment provides heating as well as cooling and humidity control to a building.
Many of the new HVAC systems surpass 16, 18 even 20 SEER, and some of the most energy-efficient heat pumps have reached 95.5% Annual Fuel Utilization Efficiency (AFUE). The 13 SEER mandate has become synonymous with more entry-level HVAC equipment, whereas the more advanced, energy-efficient systems aim for ever-higher SEER ratings. Manufacturers have also invested more in geothermal technology, and at least one, Lennox, has introduced solar assisted heating and cooling. Newer energy-efficient units not only address spiraling energy costs but also provide greater levels of comfort and improved consumer control over their immediate thermal environment.