HVAC loads often represent the biggest energy expense in commercial buildings. Buildings in the far north or south of the planet often have substantial heating costs, whilst those in the tropics may require air cooling all year.

Commercial buildings, like residential structures, have a wide choice of heating and cooling options, each with its own set of benefits and drawbacks. The following are three of the most often utilized commercial building systems:

• Variable-air-volume (VAV) systems with a rooftop unit are available.
• Systems for chillers, cooling towers, and boilers
• Heat pump systems that use water as a source of heat and include a cooling tower and a boiler

1. In climates where the unit must offer air conditioning with low outside humidity, an economizer can be added to lower the condenser’s cooling demand. Fans are used to blow air into a duct system that distributes it throughout the various indoor zones in all modes of operation. In commercial buildings, HVAC loads are sometimes the largest energy expense. Buildings in the far north and south of the world frequently have high heating expenditures, whereas those in the tropics may require air conditioning throughout the year.
2. Chiller with Cooling Tower and Boiler Water circuits pass through air-handling units (AHUs) that supply the appropriate airflow for each building zone in these systems, which employ water as a medium to transport or extract heat.