HVAC

HVAC stands for heating, ventilation, and air conditioning. It refers to the technology of indoor environmental comfort and air quality in buildings. An HVAC system typically provides space heating and cooling, maintains humidity within a target range, exchanges indoor air with outdoor air, and filters contaminants to improve indoor air quality. Systems vary in size and configuration but share the goal of providing thermal comfort and acceptable indoor air quality while operating efficiently.

Major components include heating equipment (furnaces or boilers, and heat pumps which can both heat and cool), cooling equipment (air conditioners, chillers, and heat pumps), ventilation and air distribution (ductwork, air handlers, registers, and exhaust systems), and controls (thermostats, sensors, and automated building-management systems). Common system types are central systems with ductwork, split systems with indoor and outdoor units, packaged units that combine components in a single cabinet, and ductless mini-split systems.

Operation relies on thermodynamics and control strategies to meet cooling and heating loads. Efficiency is expressed by metrics such as AFUE for furnaces, SEER for cooling, and HSPF for heat pumps, with higher values indicating greater efficiency. Modern systems often employ variable-speed compressors and smart controls to optimize energy use and comfort. Indoor air quality is addressed through filtration, humidity control, and ventilation strategies that bring in outdoor air while minimizing contaminants.

Maintenance involves regular filter replacement, coil and duct cleaning, refrigerant checks, and safety inspections, particularly for gas-fired equipment. Standards and regulations from organizations like ASHRAE and AHRI guide design, performance testing, and equipment labeling.